San Luis & Delta-Mendota Water v. Natural Resources Defense Coun ( 2014 )


Menu:
  •                 FOR PUBLICATION
    UNITED STATES COURT OF APPEALS
    FOR THE NINTH CIRCUIT
    SAN LUIS & DELTA-MENDOTA               No. 11-15871
    WATER AUTHORITY; WESTLANDS
    WATER DISTRICT; STEWART &                 D.C. No.
    JASPER ORCHARDS; ARROYO FARMS,         1:09-cv-00407-
    LLC; KING PISTACHIO GROVE;               OWW-DLB
    STATE WATER CONTRACTORS;
    METROPOLITAN WATER DISTRICT OF
    SOUTHERN CALIFORNIA; COALITION
    FOR A SUSTAINABLE DELTA; KERN
    COUNTY WATER AGENCY; FAMILY
    FARM ALLIANCE,
    Plaintiffs-Appellees,
    CALIFORNIA DEPARTMENT OF
    WATER RESOURCES,
    Intervenor-Plaintiff-Appellee,
    v.
    SALLY JEWELL, as Secretary of the
    Department of the Interior; U.S.
    DEPARTMENT OF THE INTERIOR; U.S.
    FISH & WILDLIFE SERVICE; DANIEL
    M. ASHE, as Director of the U.S.
    Fish and Wildlife Service; REN
    LOHOEFENER, as Regional Director
    of the U.S. Fish and Wildlife
    Service, Pacific Southwest Region,
    U.S. Department of the Interior;
    2                 SAN LUIS V. JEWELL
    UNITED STATES BUREAU OF
    RECLAMATION; MICHAEL L.
    CONNOR, as Commissioner of the
    U.S. Bureau of Reclamation, U.S.
    Department of the Interior; DAVID
    MURILLO, as Director of the U.S.
    Bureau of Reclamation, Mid-Pacific
    Region, U.S. Department of the
    Interior; MARK COWIN, Director,
    California Department of Water
    Resources; UNITED STATES
    DEPARTMENT OF JUSTICE; U.S.
    ENVIRONMENTAL PROTECTION
    AGENCY; GINA MCCARTHY, in her
    official capacity as Administrator of
    the Environmental Protection
    Agency; U.S. DEPARTMENT OF
    TRANSPORTATION; ANTHONY FOXX,
    in his official capacity as Secretary
    of Transportation; MARITIME
    ADMINISTRATION; PAUL N.
    JAENICHEN, SR., in his official
    capacity as Acting Maritime
    Administrator; U.S. DEPARTMENT OF
    HOMELAND SECURITY; JEH
    JOHNSON, in his official capacity as
    Secretary of Homeland Security;
    FEDERAL EMERGENCY
    MANAGEMENT AGENCY; WILLIAM
    CRAIG FUGATE, in his official
    capacity as Administrator of the
    Federal Emergency Management
    Agency; UNITED STATES ARMY
    SAN LUIS V. JEWELL                    3
    CORPS OF ENGINEERS; THOMAS P.
    BOSTICK, Commanding General and
    Chief of Engineers, United States
    Army Corps of Engineers,
    Defendants,
    and
    NATURAL RESOURCES DEFENSE
    COUNCIL; THE BAY INSTITUTE,
    Intervenor-Defendants-Appellants.
    SAN LUIS & DELTA-MENDOTA               No. 11-16617
    WATER AUTHORITY; WESTLANDS
    WATER DISTRICT; STEWART &                 D.C. No.
    JASPER ORCHARDS; ARROYO FARMS,         1:09-cv-00407-
    LLC; KING PISTACHIO GROVE;               OWW-DLB
    METROPOLITAN WATER DISTRICT OF
    SOUTHERN CALIFORNIA; COALITION
    FOR A SUSTAINABLE DELTA; KERN
    COUNTY WATER AGENCY; FAMILY
    FARM ALLIANCE,
    Plaintiffs,
    CALIFORNIA DEPARTMENT OF
    WATER RESOURCES,
    Intervenor-Plaintiff,
    and
    STATE WATER CONTRACTORS,
    Plaintiff-Appellant,
    4                 SAN LUIS V. JEWELL
    v.
    SALLY JEWELL, as Secretary of the
    Department of the Interior; U.S. FISH
    & WILDLIFE SERVICE; DANIEL M.
    ASHE, as Director of the U.S. Fish
    and Wildlife Service; REN
    LOHOEFENER, as Regional Director
    of the U.S. Fish and Wildlife
    Service, Pacific Southwest Region,
    U.S. Department of the Interior;
    UNITED STATES BUREAU OF
    RECLAMATION; MICHAEL L.
    CONNOR, as Commissioner of the
    U.S. Bureau of Reclamation, U.S.
    Department of the Interior; DAVID
    MURILLO, as Director of the U.S.
    Bureau of Reclamation, Mid-Pacific
    Region, U.S. Department of the
    Interior; UNITED STATES
    DEPARTMENT OF JUSTICE; U.S.
    ENVIRONMENTAL PROTECTION
    AGENCY; GINA MCCARTHY, in her
    official capacity as Administrator of
    the Environmental Protection
    Agency; U.S. DEPARTMENT OF
    TRANSPORTATION; ANTHONY FOXX,
    in his official capacity as Secretary
    of Transportation; MARITIME
    ADMINISTRATION; PAUL N.
    JAENICHEN, SR., in his official
    capacity as Acting Deputy Maritime
    Administrator; U.S. DEPARTMENT OF
    SAN LUIS V. JEWELL                    5
    HOMELAND SECURITY; JEH
    JOHNSON, in his official capacity as
    Secretary of Homeland Security;
    FEDERAL EMERGENCY
    MANAGEMENT AGENCY; WILLIAM
    CRAIG FUGATE, in his official
    capacity as Administrator of the
    Federal Emergency Management
    Agency; UNITED STATES ARMY
    CORPS OF ENGINEERS; THOMAS P.
    BOSTICK, Commanding General and
    Chief of Engineers, United States
    Army Corps of Engineers; U.S.
    DEPARTMENT OF THE INTERIOR,
    Defendants-Appellees,
    NATURAL RESOURCES DEFENSE
    COUNCIL; THE BAY INSTITUTE,
    Intervenor-Defendants-Appellees.
    SAN LUIS & DELTA-MENDOTA               No. 11-16621
    WATER AUTHORITY; WESTLANDS
    WATER DISTRICT; STEWART &                 D.C. No.
    JASPER ORCHARDS; ARROYO FARMS,         1:09-cv-00407-
    LLC; KING PISTACHIO GROVE;               OWW-DLB
    COALITION FOR A SUSTAINABLE
    DELTA; KERN COUNTY WATER
    AGENCY; FAMILY FARM ALLIANCE;
    STATE WATER CONTRACTORS,
    Plaintiffs,
    6                SAN LUIS V. JEWELL
    CALIFORNIA DEPARTMENT OF
    WATER RESOURCES,
    Intervenor-Plaintiff,
    and
    METROPOLITAN WATER DISTRICT OF
    SOUTHERN CALIFORNIA,
    Plaintiff-Appellant,
    v.
    SALLY JEWELL, as Secretary of the
    Department of the Interior; U.S.
    DEPARTMENT OF THE INTERIOR; U.S.
    FISH & WILDLIFE SERVICE; DANIEL
    M. ASHE, as Director of the U.S.
    Fish and Wildlife Service; REN
    LOHOEFENER, as Regional Director
    of the U.S. Fish and Wildlife
    Service, Pacific Southwest Region,
    U.S. Department of the Interior;
    UNITED STATES BUREAU OF
    RECLAMATION; MICHAEL L.
    CONNOR, as Commissioner of the
    U.S. Bureau of Reclamation, U.S.
    Department of the Interior; DAVID
    MURILLO, as Director of the U.S.
    Bureau of Reclamation, Mid-Pacific
    Region, U.S. Department of the
    Interior; UNITED STATES
    DEPARTMENT OF JUSTICE; U.S.
    ENVIRONMENTAL PROTECTION
    SAN LUIS V. JEWELL    7
    AGENCY; GINA MCCARTHY, in her
    official capacity as Administrator of
    the Environmental Protection
    Agency; U.S. DEPARTMENT OF
    TRANSPORTATION; ANTHONY FOXX,
    in his official capacity as Secretary
    of Transportation; MARITIME
    ADMINISTRATION; PAUL N.
    JAENICHEN, SR., in his official
    capacity as Acting Deputy Maritime
    Administrator; U.S. DEPARTMENT OF
    HOMELAND SECURITY; JEH
    JOHNSON, in his official capacity as
    Secretary of Homeland Security;
    FEDERAL EMERGENCY
    MANAGEMENT AGENCY; WILLIAM
    CRAIG FUGATE, in his official
    capacity as Administrator of the
    Federal Emergency Management
    Agency; UNITED STATES ARMY
    CORPS OF ENGINEERS; THOMAS P.
    BOSTICK, Commanding General and
    Chief of Engineers, United States
    Army Corps of Engineers,
    Defendants-Appellees,
    NATURAL RESOURCES DEFENSE
    COUNCIL; THE BAY INSTITUTE,
    Intervenor-Defendants-Appellees.
    8                 SAN LUIS V. JEWELL
    SAN LUIS & DELTA-MENDOTA               No. 11-16623
    WATER AUTHORITY; WESTLANDS
    WATER DISTRICT; STEWART &                 D.C. No.
    JASPER ORCHARDS; ARROYO FARMS,         1:09-cv-00407-
    LLC; KING PISTACHIO GROVE;               OWW-DLB
    STATE WATER CONTRACTORS;
    METROPOLITAN WATER DISTRICT OF
    SOUTHERN CALIFORNIA; COALITION
    FOR A SUSTAINABLE DELTA; KERN
    COUNTY WATER AGENCY; FAMILY
    FARM ALLIANCE,
    Plaintiffs-Appellees,
    CALIFORNIA DEPARTMENT OF
    WATER RESOURCES,
    Intervenor-Plaintiff-Appellee,
    v.
    SALLY JEWELL, as Secretary of the
    Department of the Interior; U.S.
    DEPARTMENT OF THE INTERIOR; U.S.
    FISH & WILDLIFE SERVICE; DANIEL
    M. ASHE, as Director of the U.S.
    Fish and Wildlife Service; REN
    LOHOEFENER, as Regional Director
    of the U.S. Fish and Wildlife
    Service, Pacific Southwest Region,
    U.S. Department of the Interior;
    UNITED STATES BUREAU OF
    RECLAMATION; MICHAEL L.
    CONNOR, as Commissioner of the
    U.S. Bureau of Reclamation, U.S.
    SAN LUIS V. JEWELL    9
    Department of the Interior; DAVID
    MURILLO, as Director of the U.S.
    Bureau of Reclamation, Mid-Pacific
    Region, U.S. Department of the
    Interior; UNITED STATES
    DEPARTMENT OF JUSTICE; U.S.
    ENVIRONMENTAL PROTECTION
    AGENCY; GINA MCCARTHY, in her
    official capacity as Administrator of
    the Environmental Protection
    Agency; U.S. DEPARTMENT OF
    TRANSPORTATION; ANTHONY FOXX,
    in his official capacity as Secretary
    of Transportation; MARITIME
    ADMINISTRATION; PAUL N.
    JAENICHEN, SR., in his official
    capacity as Acting Deputy Maritime
    Administrator; U.S. DEPARTMENT OF
    HOMELAND SECURITY; JEH
    JOHNSON, in his official capacity as
    Secretary of Homeland Security;
    FEDERAL EMERGENCY
    MANAGEMENT AGENCY; WILLIAM
    CRAIG FUGATE, in his official
    capacity as Administrator of the
    Federal Emergency Management
    Agency; UNITED STATES ARMY
    CORPS OF ENGINEERS; THOMAS P.
    BOSTICK, Commanding General and
    Chief of Engineers, United States
    Army Corps of Engineers,
    Defendants-Appellants,
    10                SAN LUIS V. JEWELL
    and
    NATURAL RESOURCES DEFENSE
    COUNCIL; THE BAY INSTITUTE,
    Intervenor-Defendants.
    SAN LUIS & DELTA-MENDOTA               No. 11-16624
    WATER AUTHORITY; WESTLANDS
    WATER DISTRICT,                           D.C. No.
    Plaintiffs-Appellants,   1:09-cv-00407-
    OWW-DLB
    and
    STEWART & JASPER ORCHARDS;
    ARROYO FARMS, LLC; KING
    PISTACHIO GROVE; COALITION FOR A
    SUSTAINABLE DELTA; KERN
    COUNTY WATER AGENCY; FAMILY
    FARM ALLIANCE; STATE WATER
    CONTRACTORS; METROPOLITAN
    WATER DISTRICT OF SOUTHERN
    CALIFORNIA,
    Plaintiffs,
    CALIFORNIA DEPARTMENT OF
    WATER RESOURCES,
    Intervenor-Plaintiff,
    v.
    SALLY JEWELL, as Secretary of the
    Department of the Interior; U.S.
    SAN LUIS V. JEWELL    11
    DEPARTMENT OF THE INTERIOR; U.S.
    FISH & WILDLIFE SERVICE; DANIEL
    M. ASHE, as Director of the U.S.
    Fish and Wildlife Service; REN
    LOHOEFENER, as Regional Director
    of the U.S. Fish and Wildlife
    Service, Pacific Southwest Region,
    U.S. Department of the Interior;
    UNITED STATES BUREAU OF
    RECLAMATION; MICHAEL L.
    CONNOR, as Commissioner of the
    U.S. Bureau of Reclamation, U.S.
    Department of the Interior; DAVID
    MURILLO, as Director of the U.S.
    Bureau of Reclamation, Mid-Pacific
    Region, U.S. Department of the
    Interior; UNITED STATES
    DEPARTMENT OF JUSTICE; U.S.
    ENVIRONMENTAL PROTECTION
    AGENCY; GINA MCCARTHY, in her
    official capacity as Administrator of
    the Environmental Protection
    Agency; U.S. DEPARTMENT OF
    TRANSPORTATION; ANTHONY FOXX,
    in his official capacity as Secretary
    of Transportation; MARITIME
    ADMINISTRATION; PAUL N.
    JAENICHEN, SR., in his official
    capacity as Acting Deputy Maritime
    Administrator; U.S. DEPARTMENT OF
    HOMELAND SECURITY; JEH
    JOHNSON, in his official capacity as
    Secretary of Homeland Security;
    12               SAN LUIS V. JEWELL
    FEDERAL EMERGENCY
    MANAGEMENT AGENCY; WILLIAM
    CRAIG FUGATE, in his official
    capacity as Administrator of the
    Federal Emergency Management
    Agency; UNITED STATES ARMY
    CORPS OF ENGINEERS; THOMAS P.
    BOSTICK, Commanding General and
    Chief of Engineers, United States
    Army Corps of Engineers,
    Defendants-Appellees,
    NATURAL RESOURCES DEFENSE
    COUNCIL; THE BAY INSTITUTE,
    Intervenor-Defendants-Appellees.
    STATE WATER CONTRACTORS,              No. 11-16660
    Plaintiff-Appellant,
    D.C. No.
    v.                    1:09-cv-00422-
    OWW-GSA
    SALLY JEWELL, as Secretary of the
    Department of the Interior; UNITED
    STATES DEPARTMENT OF JUSTICE;
    DANIEL M. ASHE, as Acting Director
    of the U.S. Fish and Wildlife
    Service; U.S. FISH & WILDLIFE
    SERVICE; MARK COWIN, Director,
    California Department of Water
    Resources; CALIFORNIA
    SAN LUIS V. JEWELL                    13
    DEPARTMENT OF WATER
    RESOURCES,
    Defendants-Appellees.
    METROPOLITAN WATER DISTRICT OF          No. 11-16662
    SOUTHERN CALIFORNIA,
    Plaintiff-Appellant,        D.C. No.
    1:09-cv-00631-
    v.                       OWW-DLB
    U.S. FISH & WILDLIFE SERVICE;
    SALLY JEWELL, Secretary of the            OPINION
    Department of the Interior; DANIEL
    M. ASHE, Acting Director of the
    U.S. Fish and Wildlife Service;
    UNITED STATES BUREAU OF
    RECLAMATION; J. WILLIAM
    MCDONALD; CALIFORNIA
    DEPARTMENT OF WATER
    RESOURCES; MARK COWIN, Director,
    California Department of Water
    Resources,
    Defendants-Appellees.
    Appeal from the United States District Court
    for the Eastern District of California
    Oliver W. Wanger, Senior District Judge, Presiding
    Argued and Submitted
    September 10, 2012—Las Vegas, Nevada
    14                    SAN LUIS V. JEWELL
    Filed March 13, 2014
    Before: Morris S. Arnold,* Johnnie B. Rawlinson,
    and Jay S. Bybee, Circuit Judges.
    Opinion by Judge Bybee;
    Partial Concurrence and Partial Dissent by Judge Arnold;
    Partial Concurrence and Partial Dissent by Judge
    Rawlinson
    *
    The Honorable Morris S. Arnold, Senior Circuit Judge for the U.S.
    Court of Appeals for the Eighth Circuit, sitting by designation.
    SAN LUIS V. JEWELL                           15
    SUMMARY**
    Environmental Law
    The panel reversed in part and affirmed in part the district
    court’s judgment invalidating a 2008 biological opinion by
    the U.S. Fish and Wildlife Service that concluded that the
    Central Valley and State Water Projects jeopardized the
    continued existence of the delta smelt and its habitat.
    The Central Valley Project and the State Water Project,
    operated respectively by the U.S. Bureau of Reclamation and
    the State of California, supply water originating in northern
    California to agricultural and domestic consumers in central
    and southern California. The source of the water—the
    estuary at the confluence of the San Francisco Bay and the
    Sacramento-San Joaquin Delta—is the lone habitat for the
    delta smelt, a threatened species under the Endangered
    Species Act (“ESA”). After the Bureau of Reclamation
    requested a biological opinion (“BiOp”), the U.S. Fish and
    Wildlife Service (“FWS”) concluded that the Central Valley
    operations would threaten the delta smelt and, as required by
    the ESA, proposed alternatives to ameliorate the effect on the
    smelt, including reducing the water exported to southern
    California. The plaintiffs-appellees—various water districts,
    water contractors, and agricultural consumers—brought suit
    under the Administrative Procedure Act against various
    federal defendants. The district court concluded that the 2008
    BiOp was arbitrary and capricious.
    **
    This summary constitutes no part of the opinion of the court. It has
    been prepared by court staff for the convenience of the reader.
    16                  SAN LUIS V. JEWELL
    Concerning the scope of the record, the panel held that the
    district court overstepped its bounds in admitting additional
    declarations from the parties’ experts. The panel held that it
    would consider the BiOp and evidence submitted by the
    parties that the FWS considered in making its decision, and
    the testimony of the four experts the district court appointed
    pursuant to Federal Rule of Evidence 706.
    Concerning the merits, the panel held that the 2008
    BiOp’s reliance on raw salvage figures to set the upper and
    lower Old and Middle Rivers flow limits was not arbitrary
    and capricious. The panel also held that the 2008 BiOp’s
    determination of X2 (the point in the Bay-Delta at which the
    salinity is less than two parts per thousand) was not arbitrary
    and capricious. The panel further held that the BiOp’s
    incidental take statement was not arbitrary and capricious
    because it included adequate explanation and support for its
    determinations. The panel also held the record supported the
    BiOp’s conclusions regarding the indirect effects of project
    operations. The panel disagreed with the district court’s
    determination that the FWS’s own regulations and the
    Administrative Procedure Act required the FWS to explain
    that the reasonable and prudent alternatives satisfied 
    50 C.F.R. § 402.02
    ’s non-jeopardy factors. The panel held that
    the FWS’s consideration of these factors could be reasonably
    discerned from the record to satisfy any explanation
    requirements.
    Concerning the cross appeal, the panel held that the FWS
    did not violate the ESA by not separating the discretionary
    from nondiscretionary actions when it set the environmental
    baseline. The panel also held that the Bureau of Reclamation
    did not violate the ESA by accepting the 2008 BiOp. The
    panel affirmed the district court’s judgment with respect to
    SAN LUIS V. JEWELL                      17
    the National Environmental Policy Act (“NEPA”) claims, and
    held: NEPA does not require the FWS to prepare an
    Environmental Impact Statement in conjunction with the
    issuance of the BiOp; and the Bureau of Reclamation’s
    provisional adoption and implementation of the BiOp
    triggered its obligation to comply with NEPA. The panel
    affirmed the district court’s order remanding to the Bureau of
    Reclamation so that it can complete an Environmental Impact
    Statement evaluating the effects of its adoption and
    implementation of the BiOp.
    Eighth Circuit Judge Arnold dissented from Parts III,
    IV.A., IV.B, IV.E, and V.B. of the majority opinion, and
    concurred in the rest. Judge Arnold would uphold the district
    court’s limited admission of evidence outside the
    administrative record as relevant to the Old and Middle River
    flow limits and determination of X2, and agreed with the
    district court that the FWS’s determination as to the flow
    prescription and X2 was arbitrary and capricious. Judge
    Arnold disagreed with the basis of the district court’s
    conclusion that the non-jeopardy elements must be addressed
    in the BiOp or administrative record, but would affirm on the
    issue. Finally, Judge Arnold believes the district court should
    have found the Bureau of Reclamation independently liable
    under the ESA for relying on a legally flawed BiOp.
    Judge Rawlinson concurred in the bulk of the majority
    opinion, but dissented from Part V.C.2. Judge Rawlinson
    disagreed only with the rationale and conclusion that the
    Bureau of Reclamation’s adoption and implementation of the
    BiOp triggered its obligation to comply with NEPA by
    preparing an Environmental Impact Statement that is
    generally required under the ESA.
    18                  SAN LUIS V. JEWELL
    COUNSEL
    Robert H. Oakley (argued), Ethan Carson Eddy, and Charles
    R. Scott, United States Department of Justice, Environment
    & Natural Resources Division, Washington, D.C.; Ignacia S.
    Moreno, United States Department of Justice, Assistant
    Attorney General, Washington, D.C.; Jim Monroe,
    Department of the Interior, Office of the Solicitor,
    Sacramento, California, for Federal Defendants-Appellants.
    Katherine Poole (argued) and Doug Obegi, Natural Resources
    Defense Council, San Francisco, California; Trent W. Orr and
    George M. Torgun, Earthjustice, San Francisco, California,
    for Defendant-Intervenors-Appellants.
    Daniel J. O’Hanlon (argued), Hanspeter Walter, and Rebecca
    R. Akroyd, Kronick, Moskovitz, Tiedemann & Girard,
    Sacramento, California; Craig Manson, General Counsel,
    Westlands Water District, Fresno, California; Steven O. Sims,
    Michelle C. Kales, and Geoffrey M. Williamson, Brownstein
    Hyatt Farber Schreck LLP, Denver, Colorado, for Plaintiffs-
    Appellees-Cross-Appellants San Luis & Delta-Mendota
    Water Authority and Westlands Water District.
    Gregory K. Wilkinson (argued), Steven M. Anderson,
    Melissa R. Cushman, and Steven G. Martin, Best Best &
    Krieger LLP, Riverside, California, for Plaintiffs-Appellees
    State Water Contractors.
    Marcia L. Scully, Interim General Counsel; Linus
    Masouredis, Chief Deputy General Counsel, The
    Metropolitan Water District of Southern California,
    Sacramento, California; Christopher J. Carr, William N.
    Sloan, and Travis Brandon, Morrison & Foerster LLP, San
    SAN LUIS V. JEWELL                    19
    Francisco, California, for Plaintiff-Appellee-Cross-Appellant
    The Metropolitan Water District of Southern California.
    Clifford T. Lee (argued), Deputy Attorney General; Kamala
    D. Harris, Attorney General of California; Kathleen A.
    Kenealy, Senior Assistant Attorney General; Robert W.
    Byrne, Supervising Deputy Attorney General; Cecilia L.
    Dennis, and Gary Alexander, Deputy Attorneys General, San
    Francisco, California, for Plaintiff-Intervenor-Appellee,
    California Department of Water Resources.
    20                           SAN LUIS V. JEWELL
    TABLE OF CONTENTS
    I. FACTS AND PROCEEDINGS BELOW. . . . . . . . . . . 26
    A. Background. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
    1. The Sacramento-San Joaquin Delta. . . . . . . . . 26
    2. The delta smelt.. . . . . . . . . . . . . . . . . . . . . . . . 31
    B. Proceedings Leading To The Present Controversy
    . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
    1. The FWS’s 2008 Biological Opinion. . . . . . . 33
    2. The present case.. . . . . . . . . . . . . . . . . . . . . . . 39
    II. STANDARDS OF REVIEW. . . . . . . . . . . . . . . . . . . . 43
    III. THE SCOPE OF THE RECORD. . . . . . . . . . . . . . . . 45
    IV. MERITS OF THE BiOp. . . . . . . . . . . . . . . . . . . . . . . 50
    A. The 2008 BiOp’s Reliance on Raw Salvage Figures to
    Set the Upper and Lower OMR Flow Limits Was Not
    Arbitrary and Capricious.. . . . . . . . . . . . . . . . . . . 53
    1. The FWS’s choice of a more conservative model
    to calculate flow limits in Figures B-13 and B-14
    was supported by substantial evidence. . . . . . 56
    2. The BiOp’s determination of OMR flow limits
    was influenced by more than Figures B-13 and B-
    14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
    SAN LUIS V. JEWELL                                       21
    3. The OMR flow limits exist as one part in a
    dynamic monitoring system that accounts for the
    smelt population as a whole.. . . . . . . . . . . . . . 71
    B. The 2008 BiOp’s Determination of X2 Was Not
    Arbitrary and Capricious.. . . . . . . . . . . . . . . . . . . 74
    1. The FWS was not arbitrary and capricious in
    comparing DAYFLOW to CALSIM II. . . . . . 75
    2. The BiOp sufficiently explained the fall X2
    locations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
    C. The BiOp’s Incidental Take Statement Is Not Flawed
    . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
    1. The ITS reasonably uses different data sets for
    adult and juvenile take limits. . . . . . . . . . . . . . 93
    2. The FWS reasonably uses an average cumulative
    salvage index. . . . . . . . . . . . . . . . . . . . . . . . . . 94
    D. The Record Supports the BiOp’s Conclusions
    Regarding the Indirect Effects of Project Operations
    . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
    1. Project operations indirectly affect smelt food
    supply. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
    2. Project operations indirectly affect the smelt
    through water contamination. . . . . . . . . . . . . 101
    22                           SAN LUIS V. JEWELL
    3. Project operations indirectly affect the smelt
    through the “other stressors” of predation,
    macrophytes, and microcystis. . . . . . . . . . . . 103
    a. Predation. . . . . . . . . . . . . . . . . . . . . . . . . . 104
    b. Aquatic Macrophytes. . . . . . . . . . . . . . . . 107
    c. Microcystis. . . . . . . . . . . . . . . . . . . . . . . . 109
    E. The FWS Is Not Required to Support the “Non-
    Jeopardy” Elements of its RPA. . . . . . . . . . . . . . 110
    V. CROSS-APPEAL.. . . . . . . . . . . . . . . . . . . . . . . . . . . 119
    A. Segregating Discretionary From Nondiscretionary
    Actions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119
    B. Reclamation Did Not Violate the ESA by Accepting
    the 2008 BiOp. . . . . . . . . . . . . . . . . . . . . . . . . . . 124
    C. Application of NEPA to the FWS and Reclamation
    . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
    1. Application of NEPA to the FWS. . . . . . . . . 127
    2. Application of NEPA to Reclamation. . . . . . 133
    VI. CONCLUSION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153
    GLOSSARY OF TERMS. . . . . . . . . . . . . . . . . . . . . . . . 154
    PARTIAL DISSENT BY JUDGE ARNOLD. . . . . . . . . 155
    PARTIAL DISSENT BY JUDGE RAWLINSON. . . . . 161
    SAN LUIS V. JEWELL                             23
    OPINION
    BYBEE, Circuit Judge, with whom ARNOLD, Circuit Judge,
    joins as to Parts I, II, IV.C, IV.D, V.A, and V.C, and with
    whom RAWLINSON, Circuit Judge, joins except as to Part
    V.C.2:
    As the district court aptly put it, these cases arise from the
    “continuing war over protection of the delta smelt.” San Luis
    & Delta-Mendota Water Auth. v. Salazar, 
    760 F. Supp. 2d 855
    , 863 (E.D. Cal. 2010). We are joined to the fray. The
    district court invalidated a biological opinion by the Fish and
    Wildlife Service that concluded that the Central Valley and
    State Water Projects jeopardize the continued existence of a
    three-inch fish and its habitat. We reverse in part and affirm
    in part.
    The Central Valley Project and the State Water Project,
    operated respectively by the Bureau of Reclamation
    (Reclamation)1 and the State of California, are perhaps the
    two largest and most important water projects in the United
    States. These combined projects supply water originating in
    northern California to more than 20,000,000 agricultural and
    domestic consumers in central and southern California. The
    source of this water, the estuary at the confluence of the San
    Francisco Bay and Sacramento-San Joaquin Delta (Bay-
    Delta), is also the lone habitat for the delta smelt, a threatened
    species under the Endangered Species Act. 
    16 U.S.C. § 1531
    et seq.
    1
    See the Glossary of Terms at the end of this opinion for a complete list
    of abbreviations and acronyms.
    24                     SAN LUIS V. JEWELL
    In 2008, Reclamation requested a biological opinion
    (BiOp) from the U.S. Fish and Wildlife Service (FWS), in
    accord with the Endangered Species Act (ESA), on whether
    its continued operations would jeopardize the smelt. In a
    more than 400-page opinion—described by the FWS as the
    most complex biological opinion ever prepared—the FWS
    concluded that the Central Valley operations would threaten
    the delta smelt and, as required by the Endangered Species
    Act, proposed “reasonable and prudent alternatives” that
    Reclamation should take to ameliorate the effect on the smelt.
    The alternatives recommended by the FWS would reduce the
    water exported from northern California to southern
    California through the Central Valley and State Water
    Projects. Reclamation has notified the FWS that it intends to
    operate the Projects in compliance with the biological
    opinion.
    The plaintiffs-appellees—various water districts, water
    contractors, and agricultural consumers2—brought suit under
    the Administrative Procedure Act against various federal
    defendants, including Reclamation, the FWS, and the
    Secretary of the Interior, to prevent the federal defendants
    from implementing the biological opinion and its proposed
    alternatives.    The district court, in a lengthy and
    comprehensive opinion, was deeply critical of the biological
    opinion and concluded that it was arbitrary and capricious.
    The court accused the FWS of repeatedly “ignoring [the] best
    science available” to reach a “results-driven choice.” 
    760 F. Supp. 2d at 940
    , and “show[ing] no inclination to fully and
    2
    The plaintiffs-appellees include the San Luis & Delta-Mendota Water
    Authority, the Westlands Water District, Stewart & Jasper Orchards, the
    California Department of Water Resources, and the Metropolitan Water
    District of Southern California.
    SAN LUIS V. JEWELL                      25
    honestly address water supply needs beyond the species,”
    even as it “interdict[s] the water supply for domestic human
    consumption and agricultural use for over twenty million
    people who depend on the Projects for their water supply,” 
    id.
    at 956–57 (quoting the FWS).
    We are acutely aware of the consequences of this
    proceeding. As a court, however, we are limited in our
    review of matters within the expertise of an agency. We may
    review the FWS’s biological opinion and Reclamation’s
    implementation for arbitrariness, caprice, or actions otherwise
    not in accordance with law. 
    5 U.S.C. § 706
    (2)(A). Although
    the FWS must employ “the best scientific and commercial
    data available,” 
    16 U.S.C. § 1536
    (a)(2), it is “not required to
    support its finding that a significant risk exists with anything
    approaching scientific certainty,” Indus. Union Dep’t v. Am.
    Petroleum Inst., 
    448 U.S. 607
    , 656 (1980) (plurality opinion).
    And, “[w]hen examining this kind of scientific determination
    . . . a reviewing court must generally be at its most
    deferential.” Baltimore Gas & Elec. Co. v. NRDC, 
    462 U.S. 87
    , 103 (1983). For the reasons explained below, we
    conclude that the district court failed to observe these
    standards and we reverse its judgment.
    We recognize the enormous practical implications of this
    decision. But the consequences were prescribed when
    Congress determined that “these species of fish, wildlife, and
    plants are of esthetic, ecological, educational, historical,
    recreational, and scientific value to the Nation and its
    people.” 
    16 U.S.C. § 1531
    (a)(3). As the Supreme Court
    observed in Tennessee Valley Authority v. Hill: “It may seem
    curious to some that the survival of a relatively small number
    of three-inch fish . . . would require the permanent halting of
    a virtually completed dam,” but “the explicit provisions of the
    26                   SAN LUIS V. JEWELL
    Endangered Species Act require precisely that result.”
    
    437 U.S. 153
    , 172–73 (1978). Such species have been
    “afforded the highest of priorities,” by Congress, even if it
    means “the sacrifice of the anticipated benefits of the project
    and of many millions of dollars in public funds.” 
    Id. at 174
    (footnote omitted). The law prohibits us from making “such
    fine utilitarian calculations” to balance the smelt’s interests
    against the interests of the citizens of California. 
    Id. at 187
    .
    Consequently, any other “[r]esolution of these fundamental
    policy questions” about the allocation of water resources in
    California “lies . . . with Congress and the agencies to which
    Congress has delegated authority, as well as with state
    legislatures and, ultimately, the populace as a whole.”
    Baltimore Gas & Elec., 
    462 U.S. at 97
    .
    I. FACTS AND PROCEEDINGS BELOW
    A. Background
    1. The Sacramento-San Joaquin Delta
    “The history of California water development and
    distribution is a story of supply and demand. California’s
    critical water problem is not a lack of water but uneven
    distribution of water resources.” United States v. State Water
    Res. Control Bd., 
    182 Cal. App.3d 82
    , 98 (Cal. Ct. App.
    1986). California’s Central Valley comprises some of the
    most productive farmland in the world. Extending 450 miles
    from north to south, and averaging 100 miles wide east to
    west, the Central Valley includes two principal rivers: The
    Sacramento River begins in the northern part of the valley,
    runs south past Sacramento, and is fed by the Feather and
    American Rivers. The San Joaquin River begins in the Sierra
    Nevadas, northeast of Fresno, runs west and northwest into
    SAN LUIS V. JEWELL                      27
    the Central Valley, and is fed by smaller rivers, including the
    Calaveras, Chowchilla, Fresno, Kings, Merced, Mokelumne,
    Stanislaus, and Tuolumne Rivers. The two rivers converge in
    the Sacramento-San Joaquin Delta and form an estuary that
    joins Suisun Bay, San Francisco Bay, and the Pacific Ocean.
    Although over 70 percent of California’s water originates
    north of Sacramento, more than 70 percent of the state’s
    demand is in the south. The water from this region supplies
    irrigation for seven million acres of agriculture and more than
    twenty million people, nearly half of California’s residents.
    See Where Does California’s Water Come From?,
    Aquafornia, The California Water News Blog, Aug. 13, 2008,
    9:29 a.m., http://www.aquafornia.com/index.php/where-does-
    californias-water-come-from/. See generally Dugan v. Rank,
    
    372 U.S. 609
    , 612–13 (1963); United States v. Gerlach Live
    Stock Co., 
    339 U.S. 725
    , 728–29 (1950); San Luis & Delta-
    Mendota Water Auth. v. United States, 
    672 F.3d 676
    , 681–83
    (9th Cir. 2012); Westlands Water Dist. v. United States,
    
    337 F.3d 1092
    , 1095–96 (9th Cir. 2003); In re Bay-Delta
    Programmatic Envtl. Impact Report Coordinated
    Proceedings, 
    184 P.3d 709
    , 715–17 (Cal. 2008); State Water
    Res. Control Bd., 182 Cal. App.3d at 97–100.
    In an effort to manage the increasing and conflicting
    demands placed on the water flowing through the
    Sacramento-San Joaquin Delta region, California and the
    United States have embarked on two massive projects. First,
    in 1933, California proposed the Central Valley Project
    (CVP), a plan to transfer water from the Sacramento River to
    water-deficient areas in the San Joaquin Valley and from the
    San Joaquin River to the southern regions of the Central
    Valley. State Water Res. Control Bd., 182 Cal. App.3d at
    98–100. Reclamation took over the project in 1935, and it is
    now “the largest federal water management project in the
    28                  SAN LUIS V. JEWELL
    United States.” Central Delta Water Agency v. United States,
    
    306 F.3d 938
    , 943 (9th Cir. 2002). The CVP consists of a
    series of dams, including Shasta, Folsom, and Nimbus Dams;
    21 reservoirs; 11 hydropower plants; and 500 miles of canals
    and aqueducts. In re Bay-Delta, 184 P.3d at 716 n.1. In
    1992, Congress adopted the Central Valley Project
    Improvement Act (CVPIA), Pub. L. No. 102-575, 
    106 Stat. 4706
    , which Congress described as designed “to achieve a
    reasonable balance among competing demands for use of
    Central Valley Project water, including the requirements of
    fish and wildlife, agricultural, municipal and industrial and
    power contractors.” CVPIA, § 3402(f), 106 Stat. at 4706.
    In 1951, California approved what is known as the State
    Water Project (SWP), the largest state-built water project in
    the United States. San Luis & Delta-Mendota Water Auth.,
    
    672 F.3d at 683
    . Managed by the California Department of
    Water Resources (DWR), “[t]he SWP serves the domestic
    water needs of approximately two-thirds of all Californians,”
    principally in Southern California. In re Bay-Delta, 184 P.3d
    at 716. SWP consists of “21 dams and reservoirs, . . . five
    power plants, 16 pumping plants, and 662 miles of aqueduct.”
    Id. at 716 n.2. In 1994, eight state agencies and 10 federal
    agencies formed the CALFED Bay-Delta Program
    (CALFED) to address comprehensively the challenges of
    managing the Bay-Delta estuary. Id. at 717.
    The CVP and SWP each operate a major station for
    pumping water from the Bay-Delta to canals and aqueducts
    that will carry the water to the south. Both plants are located
    near Tracy, California, and together they reverse the natural
    flow of the southern part of the Bay-Delta through two
    distributaries of the San Joaquin, Old, and Middle Rivers,
    referred to as “OMR.” San Luis & Delta-Mendota, 760 F.
    SAN LUIS V. JEWELL                       29
    Supp. 2d at 863. The CVP operates the Jones Pumping Plant,
    capable of diverting 4,600 cubic feet per second (cfs).
    Nearby, the SWP operates the Harvey O. Banks Pumping
    Plant, with a capacity of 10,300 cfs, although it generally
    operates at or below 6,680 cfs. BiOp at 82, 108, 159–60.
    The plants have been constructed with louvers that allow
    water to pass through into the pumping plant, but will prevent
    most fish from entering the plants. The process of the fish
    entering the plants, known as entrainment, traps some 52
    different species of fish. BiOp at 67. The salvaged fish are
    hauled in trucks injected with oxygen and released at sites on
    the Sacramento and San Joaquin Rivers. BiOp at 67, 145.
    Over a recent 15-year period, more than 110 million fish were
    salvaged from the Jones and Banks facility. BiOp at 160.
    This number, however, greatly underestimates the number of
    fish actually entrained at the facilities, because fish less than
    30 mm (1.2 inches) are not efficiently collected at the
    louvers. BiOp at 160–61. Smaller fish, especially those in the
    juvenile or larval stage, are killed in the pumps. BiOp at 210.
    Those that are salvaged frequently do not survive the salvage
    process. BiOp at 338.
    The Colorado River and the SWP have historically been
    the major supply of water for southern California. As the
    result of an interstate agreement signed in 2003, California
    will receive less water from the Colorado River.
    Quantification Settlement Agreement, San Diego Water
    Authority, http://www.sdcwa.org/quantification-settlement-
    agreement (last visited July 29, 2013). As a consequence,
    southern California has sought more water from SWP. BiOp
    at 89–90. Increased demand for water from SWP has had a
    predictable effect on the water flowing into the Bay-Delta.
    As more water is diverted from the rivers that feed the Delta
    into the southern Central Valley, the salinity of the Delta and
    30                   SAN LUIS V. JEWELL
    its estuaries increases along with the threat to the species that
    thrive there.
    The Delta generally describes a large
    lowland area with a labyrinth of natural
    channels in and around the confluence of the
    Sacramento and San Joaquin Rivers. . . .
    The major factor affecting water quality in
    the Delta is saltwater intrusion. Delta Lands,
    situated at or below sea level, are constantly
    subject to ocean tidal action. Salt water
    entering from San Francisco Bay extends well
    into the Delta, and intrusion of the saline tidal
    waters is checked only by the natural barrier
    formed by fresh water flowing out from the
    Delta.
    State Water Resources Control Bd., 182 Cal. App.3d at 107.
    Since the 1970s, Reclamation and a raft of state agencies
    have worked to mitigate the effects of increased water salinity
    on Suisun Bay resulting from the upstream diversion of water
    that would otherwise naturally flow through Suisun. BiOp at
    112–13. Salinity levels in Suisun Bay are highly sensitive to
    diversion from the Delta.
    Two related standards are used to describe the salinity of
    the Bay-Delta. The first is the Low Salinity Zone or LSZ.
    BiOp at 147. The LSZ is the transition point between the
    freshwater of the inland rivers and brackish water flowing
    eastward from San Francisco Bay and the Pacific Ocean, and
    includes water ranging in salinity from 0.5 parts per thousand
    to six parts per thousand. BiOp at 191. The second is
    referred to as X2. X2 represents the point in the Bay-Delta at
    SAN LUIS V. JEWELL                           31
    which the salinity is less than two parts per thousand. See
    Westlands Water Dist. v. Dep’t of Interior, 
    376 F.3d 853
    , 876
    (9th Cir. 2004). The LSZ, which encompasses a larger region
    of the Bay-Delta, is generally centered around X2. Together,
    these regions are largely determined by Bay-Delta outflow,
    which is the difference between the inflow and the water
    exported. The agencies use X2 as a marker for the LSZ as
    well as a habitat indicator for fish and as a regulatory
    standard. BiOp at 149–50, 236; San Luis & Delta Mendota,
    
    760 F. Supp. 2d at
    864 & nn.4–5. They express the location
    of X2 as its distance in kilometers east of the Golden Gate
    Bridge, Westlands Water Dist., 
    376 F.3d at 876
    .
    2. The delta smelt
    The delta smelt (Hypomesus transpacificus) is a small,
    two-to-three inch species of fish endemic to the San
    Francisco Bay/Sacramento-San Joaquin Delta Estuary. BiOp
    at 140–41. Once an abundant species in the Bay-Delta
    ecosystem, the delta smelt is now in imminent danger of
    extinction. In March 1993, the species was listed as
    threatened under the ESA, and the FWS designated the Bay-
    Delta system a critical habitat for the delta smelt in 1994.3
    
    50 C.F.R. § 17.11
    ; BiOp at 140. Yet, over the past decade,
    the delta smelt population has been decimated even relative
    to these depleted levels, with a measured decline since 2000
    3
    In 1990, the National Marine Fisheries Service listed the Sacramento
    River winter-run chinook salmon as a threatened species under the
    Endangered Species Act. 
    50 C.F.R. § 227.4
    ; Orff v. United States,
    
    545 U.S. 596
    , 599 (2005); O’Neill v. United States, 
    50 F.3d 677
    , 681 (9th
    Cir. 1995). This case does not involve the salmon.
    32                      SAN LUIS V. JEWELL
    of up to three orders of magnitude below historic lows.4 San
    Luis & Delta-Mendota, 
    760 F. Supp. 2d at 866
    . As a
    consequence, the FWS announced in 2010 that reclassifying
    the delta smelt from a threatened to an endangered species
    was warranted but precluded by higher priority listings.5 
    Id.
    The ESA provides “both substantive and procedural
    provisions designed to protect endangered species and their
    habitat.” Am. Rivers v. Nat’l Marine Fisheries Serv.,
    
    126 F.3d 1118
    , 1121 (9th Cir. 1997).6 One such protection,
    § 7(a)(2) of the ESA, requires federal agencies to “insure that
    any action authorized, funded, or carried out by such agency
    . . . is not likely to jeopardize the continued existence of any
    endangered species or threatened species or result in the
    destruction or adverse modification of habitat of such
    species.” 
    16 U.S.C. § 1536
    (a)(2). Should the agency find that
    its proposed action may affect a listed species or critical
    habitat, it must formally or informally consult with the
    Secretary of the Interior, or his or her delegee. 
    16 U.S.C. § 1536
    (a)(4); 
    50 C.F.R. § 402.14
    (a); see Am. Rivers, 
    126 F.3d at 1122
    . If no effect is found, consultation is not required.
    4
    The 2008 delta smelt population was estimated at 1.5% of the 1980
    level, 
    75 Fed. Reg. 17667
     (April 7, 2010), and 2009 levels were estimated
    to be the lowest on record. San Luis & Delta-Mendota, 
    760 F. Supp. 2d at 866
    .
    5
    The delta smelt was assigned a listing priority of 2 on a scale from 1
    to 12, with 1 being the highest priority. San Luis & Delta-Mendota, 
    760 F. Supp. 2d at
    866–67 n.6.
    6
    Among other things, the CVPIA instructs the Secretary of the Interior
    to “operate the Central Valley Project to meet all obligations under State
    and Federal law, including but not limited to the Federal Endangered
    Species Act, 
    16 U.S.C. § 1531
     et seq.” CVPIA, § 3406(b), 106 Stat. at
    4714.
    SAN LUIS V. JEWELL                       33
    
    50 C.F.R. § 402.14
    . Formal consultation is required when the
    acting agency or consulting agency determines that the
    proposed action is likely to adversely affect a listed species or
    critical habitat. 
    50 C.F.R. §§ 402.13
    , 402.14. Formal
    consultation requires the consulting agency, here the FWS, to
    issue a biological opinion stating whether the proposed action
    is likely to jeopardize such species or habitat. 
    16 U.S.C. § 1536
    (b); 
    50 C.F.R. § 402.14
    . Should the action jeopardize
    the species or habitat, the consulting agency must suggest any
    “reasonable and prudent alternatives” (RPA) that would allow
    the projects to continue operation without causing jeopardy
    to the species or adverse modification to its critical habitat.
    
    16 U.S.C. § 1536
    (b)(3)(A). Once it receives the BiOp, the
    acting agency “shall determine whether and in what manner
    to proceed with the action in light of its section 7 obligations
    and the [FWS’s] biological opinion.” 
    50 C.F.R. § 402.15
    (a).
    If, after consultation, the agency determines that it cannot
    comply with § 7(a)(2), it may apply for an exemption, which
    can only be authorized by the Endangered Species
    Committee, an ad hoc panel composed of executive branch
    members and at least one appointee from the state in which
    the project is to occur. 
    16 U.S.C. § 1536
    (e); 
    50 C.F.R. §§ 402.15
    (c), 451.
    B. Proceedings Leading To The Present Controversy
    1. The FWS’s 2008 Biological Opinion
    Reclamation sought a biological opinion from the FWS as
    part of its continued long-term operation of the CVP and its
    coordinated operations with state agencies of the SWP. BiOp
    34                      SAN LUIS V. JEWELL
    at 1, 8.7 Following § 7(a)(2) review and a subsequent formal
    consultation, the FWS issued a biological opinion in 2005
    (2005 BiOp). The 2005 BiOp found that the proposed
    coordinated operations of the CVP and SWP would not have
    an adverse effect on the continued existence and recovery of
    the delta smelt and its critical habitat. San Luis & Delta-
    Mendota, 
    760 F. Supp. 2d at 863
    . The Natural Resources
    Defense Council—defendants-intervenors-appellants in the
    present case—challenged the FWS’s conclusion in U.S.
    District Court for the Eastern District of California, and the
    court found the 2005 BiOp arbitrary and capricious.
    Kempthorne, 506 F. Supp. 2d at 387. After conducting an
    extensive evidentiary hearing, the district court issued an
    interim remedial order and findings of fact and conclusions
    of law, which covered, among other things, the effects on
    delta smelt of negative flows in OMR. See San Luis & Delta-
    Mendota, 
    760 F. Supp. 2d at 864
    . The district court ordered
    Reclamation and DWR to implement a winter “pulse flow”
    in OMR of no more negative than !2,000 cfs, and to “operate
    the CVP and SWP to achieve a daily average net upstream
    (reverse) flow in the OMR not to exceed !5,000 cfs on a
    seven-day running average during a defined period in the
    spring.”8 Id.; Int. Rem. Order at 5–7. The district court also
    7
    The precipitating event for Reclamation seeking a biological opinion
    was a 2004 Operating Criteria and Plan (OCAP), reflecting changes in
    facilities, water delivery requirements, and regulatory restrictions and
    increasing coordination between federal and state agencies. NRDC v.
    Kempthorne, 
    506 F. Supp. 2d 322
    , 330 (E.D. Cal. 2007).
    8
    When water is diverted from the Bay-Delta contrary to its natural
    course, the amount of water exported is usually expressed as a negative
    number because the pumping plants reverse OMR flow. For example, if
    the Banks facility is pumping 2,500 cubic feet per second to the California
    Aqueduct, it is noted as !2,500 cfs.
    SAN LUIS V. JEWELL                            35
    ordered the FWS to complete a new BiOp in just nine
    months, a deadline that it would ultimately extend to one
    year. San Luis & Delta-Mendota, 
    760 F. Supp. 2d at 865
    ; Int.
    Rem. Order at 2.
    The FWS issued a new delta smelt biological opinion on
    the deadline, December 15, 2008 (2008 BiOp or BiOp).9
    BiOp at 1–396. In stark contrast to the 2005 BiOp, the 2008
    BiOp concluded that the “coordinated operations of the CVP
    and SWP, as proposed, are likely to jeopardize the continued
    existence of the delta smelt” and “adversely modify delta
    smelt critical habitat.” BiOp at 276–78. With respect to the
    delta smelt, the FWS entered five findings of fact:
    (1) “Diversions of water from the Delta have increased since
    1967 when the SWP began operation in conjunction with the
    CVP.” BiOp at 276. The CVP/SWP operations have
    entrained smelt, including adults, larvae, and juveniles, at the
    Banks and Jones facilities; reduced smelt habitat; and reduced
    the Delta outflows, altering the location of the LSZ; (2) “The
    delta smelt is currently at its lowest level of abundance since
    monitoring began in 1967”; (3) “Under the proposed
    CVP/SWP operations, inflows to the Delta are likely to be
    further reduced, as water demands upstream of the Delta
    increase, most notably on the American River.” BiOp at 276.
    This is likely to “cause increased relative entrainment of adult
    delta smelt in the winter and spring, and of larval and juvenile
    9
    In preparing this BiOp, the FWS subjected it to an Internal Peer
    Review Team, consisting of experts in the development of complex
    biological opinions under the ESA from throughout the FWS, comments
    from a team of delta smelt experts from within the FWS and other related
    agencies, the review of PBS&J, an environmental consulting firm, as well
    as feedback from Reclamation and the DWR. See BiOp at i–vi. In
    response to the significant feedback it received, the FWS made substantial
    changes to the BiOp. See BiOp at ii.
    36                  SAN LUIS V. JEWELL
    delta smelt in the spring”; (4) “Other baseline stressors will
    continue to adversely affect the delta smelt, such as
    contaminants, microcystis, aquatic macrophytes, and invasive
    species”; (5) To recover, delta smelt will need a more
    abundant adult population, an increase in the quality and
    quantity of spawning, rearing, and migratory habitat, a
    reduction in contaminants and pollutants, a reduction in
    exposure to disease and toxic algal blooms, and a reduction
    in entrainment at water-diversion facilities in the Bay-Delta.
    BiOp at 276–77. With respect to delta smelt critical habitat,
    the FWS found that “past and present operations of the
    CVP/SWP have degraded these habitat elements” such that
    they are “insufficient to support successful delta smelt
    recruitment at levels that will provide for the species’
    conservation.” BiOp at 278.
    The FWS recommended five components and listed six
    separate actions as “reasonable and prudent alternatives”
    (RPA):
    RPA Component 1 (Actions 1 and 2). Component 1
    protects the adult delta smelt life stage by controlling OMR
    flows during the vulnerable December to March period. It
    has two proposed actions. Action 1 is “designed to protect
    upmigrating delta smelt” and describes the two periods when
    delta smelt are most vulnerable to entrainment: in December
    and when the first flush appears. BiOp at 280–81. Action 1
    therefore proposes limiting the negative flows at OMR based
    on a “daily salvage index.” 
    Id.
     In effect, this means that
    when the “daily salvage index” reaches a critical point (“the
    risk threshhold”), the Projects have to reduce their diversion
    for 14 days. During that period, OMR flows can be “no more
    negative than !2,000 cfs” for a 14-day running average and
    “no more negative than -2,500 cfs” for a 5-day running
    SAN LUIS V. JEWELL                              37
    average. BiOp at 281, 329. Action 2 follows from Action 1
    but covers the period from December through March, when
    pre-spawning adult delta smelt are vulnerable to entrainment.
    BiOp at 352. During that period, OMR flows can be no more
    negative than !5,000 cfs, although the FWS expected that
    flows would generally be in the range of !2,000 cfs to !3,500
    cfs.
    RPA Component 2 (Action 3). Component 2 protects
    larval and juvenile delta smelt by limiting OMR flows
    following the completion of Component 1 when the Bay-
    Delta water temperatures reach 12EC, or when a spent female
    smelt is detected in trawls at Jones or Banks or is found in the
    salvage facilities. Action 3 requires the CVP/SWP projects
    to maintain their average OMR flows between !1,250 and
    !5,000 cfs until June 30, or until the mean water temperature
    reaches a target level, whichever occurs earlier. BiOp at 290,
    357–58.
    RPA Component 3 (Action 4). Component 3 improves
    smelt habitat by increasing Bay-Delta outflow during the fall.
    Action 4 requires that in September and October, in years
    when the precipitation and runoff is defined as “wet or above
    normal,” Reclamation and DWR must provide sufficient
    Delta outflow to maintain X2 no more eastward than 74 km
    from the Golden Gate in wet years and 81 km in above-
    normal years.10 BiOp at 282–83, 369.
    10
    In Action 4, the FWS noted that “there may be other ways to achieve
    the biological goals of this action,” and that it would evaluate alternatives
    and modify Action 4 “consistent with the intention of this action.” The
    FWS referred to this process as an “adaptive management process.” BiOp
    at 283.
    38                        SAN LUIS V. JEWELL
    RPA Component 4 (Action 611). Component 4 restores
    habitat by establishing a program to create or restore
    intertidal and associated subtidal habitat to the Bay-Delta and
    Suisun Marsh. Action 6 requires DWR to create or restore at
    least 8,000 acres in the Delta and Suisun Marsh. BiOp at 283.
    RPA Component 5. Component 5 monitors and reports on
    the implementation, success, and possible improvements of
    Components 1–4.12
    Finally, the FWS issued an “incidental take statement”
    (ITS) in accord with 
    50 C.F.R. § 402.02
    . For purposes of the
    ITS, the FWS presumed that its reasonable and prudent
    alternatives would be implemented. Based on that premise,
    the FWS found that, as a result of CVP/SWP operations, there
    would be a take of the delta smelt, and that although the
    extent of the take would be difficult to estimate, smelt
    entrainment would be minimized when OMR flows were
    regulated according to the FWS’s proposed RPA. BiOp at
    285–86. As a consequence, the FWS concluded that “this
    level of anticipated take is not likely to result in jeopardy to
    the species or destruction or adverse modification of critical
    habitat when the RPA is implemented.” BiOp at 293.
    11
    For Action 5 see, infra, Note 12.
    12
    Component 5 did not have a separate action item, and Action 5 was
    not formally associated with any of the RPA Components. Action 5 was
    specific to the installation of a physical barrier on the Old River that
    affected entrainment of larval and juvenile delta smelt. BiOp at 377–78.
    SAN LUIS V. JEWELL                               39
    2. The present case
    The first of six complaints challenging the FWS’s 2008
    BiOp was filed in March 2009. San Luis & Delta-Mendota,
    
    760 F. Supp. 2d at 865
    . “Plaintiffs moved for a preliminary
    injunction . . . to prevent Reclamation from implementing
    Component 2 of the RPA, alleging that FWS violated the
    National Environmental Policy Act (“NEPA”) and the ESA.”
    
    Id.
     The district court granted the motion in part, finding that
    plaintiffs-appellees were likely to succeed on the merits of
    their NEPA claim, and requiring the FWS to make specific
    written findings to justify weekly decisions regarding OMR
    flow restrictions. 
    Id.
    Plaintiffs-appellees sought a preliminary injunction
    against the implementation of RPA Component 3. 
    Id.
    Following an evidentiary hearing,13 the district court issued
    a preliminary injunction confirming that plaintiffs-appellees
    had succeeded on their NEPA claims and finding that
    13
    At the evidentiary hearing, the district court appointed four experts
    pursuant to Federal Rule of Evidence 706, which permits the court to
    “appoint any expert that the parties agree on and any of its own choosing.”
    Fed. R. Evid. 706(a). The court appointed two professors from the
    University of Washington, Dr. Andre Punt and Dr. Thomas Quinn, to
    advise the court on the complex technical and scientific matters. The
    court also appointed two additional experts: a Reclamation employee
    knowledgeable on the CVP, and a DWR employee knowledgeable in the
    SWP.
    In addition to these court-appointed experts, the district court
    permitted substantial declarations from experts selected (but not agreed to)
    by the parties. In its written decision, the district court relied extensively
    on opinions and evidence submitted by its own experts and by the parties’
    experts.
    40                  SAN LUIS V. JEWELL
    plaintiffs-appellees were likely to succeed on the merits of
    their ESA claim. 
    Id.
    In December 2010, the district court entered final
    judgment on the primary claims in a 115-page opinion. 
    Id.
     at
    967–70. Although the FWS’s 2008 BiOp reached antipodal
    conclusions to the 2005 BiOp—which reached a no-jeopardy
    conclusion and was found arbitrary and capricious—the
    district court once again found the 2008 BiOp to be arbitrary
    and capricious under the ESA and the APA and remanded the
    BiOp, its RPA, and Reclamation’s provisional acceptance of
    the RPA to the agency. San Luis & Delta-Mendota, 
    760 F. Supp. 2d at 855, 970
    . The court’s remand required the
    completion of yet a third BiOp analyzing the impact of CVP
    and SWP operations on the delta smelt. San Luis & Delta-
    Mendota, 
    760 F. Supp. 2d at 870
    . In March 2011, the district
    court entered final judgment on all remaining claims.
    Although the district court accepted the BiOp’s central
    conclusion that “Project operations are likely to jeopardize
    the continued existence and/or adversely modify the critical
    habitat of the delta smelt,” 
    id. at 969
    , the district court
    determined that there were a number of specific flaws with
    the BiOp, 
    id.
     at 967–70. We will briefly set forth the district
    court’s principal objections here—which are highly technical
    and somewhat obtuse out of context—and explain them in
    more detail in the discussion section.
    First, the district court found the BiOp’s reliance on
    analyses using raw salvage figures—e.g., those calculations
    that incorporated the absolute “raw” number of smelt
    entrained in pumping stations, as opposed to the smelt
    entrained as a percentage of the total population—to be
    arbitrary and capricious and not the result of the best
    SAN LUIS V. JEWELL                      41
    available science. 
    Id. at 968
    . These calculations significantly
    influenced the upper and lower OMR flow limits in Actions
    1, 2, and 3.
    Second, the district court found that the BiOp’s use of two
    different models, CALSIM II and DAYFLOW, that predict
    the location of X2, introduced bias requiring a corrective
    calibration or, at the very least, explanation. 
    Id.
     The district
    court also found that the bias produced by the comparison of
    CALSIM II to DAYFLOW tainted the BiOp’s justification
    for Action 4, which involves the management of X2. In
    addition, the district court found that the BiOp did not
    sufficiently explain why it is essential in Component 3
    (Action 4) to maintain X2 at the specific locations of 74 km
    upstream from the Golden Gate Bridge following “wet years”
    and 81 km following “above-normal years.” 
    Id. at 969
    .
    Third, the district court found that the BiOp did not
    sufficiently explain why different data sets were used to
    calculate the incidental take limit for juvenile and for adult
    smelt, and why these limits were calculated using an average
    of previous years’ smelt salvage (which would be expected to
    be exceeded in 50% of all future years).
    Fourth, the district court found the BiOp did not
    adequately support its conclusions that Project operations are
    reasonably certain to indirectly affect the delta smelt by
    limiting delta smelt food supply, by increasing harmful
    pollution and contaminants, and by increasing the detrimental
    impact of the “other stressors” of predation, macrophytes, and
    microcystis on delta smelt. 
    Id.
    Fifth, the district court held that the BiOp failed to
    analyze economic feasibility, consistency with the purpose of
    42                    SAN LUIS V. JEWELL
    the action, and consistency with the action agency’s authority,
    as required by § 402.02. See 
    5 U.S.C. § 551
     et seq; 
    50 C.F.R. § 402.02
    . 
    Id.
     at 969–70.
    Federal Defendants and the NRDC have timely appealed,
    urging reversal of the district court’s remand. We address
    their claims in Part IV.
    The San Luis & Delta-Mendota Water Authority and
    other appellees timely cross-appealed, arguing that the district
    court did not go far enough. They raise three claims: First,
    that the FWS violated the ESA by not separating out non-
    discretionary actions from discretionary actions in setting an
    environmental baseline; second, that Reclamation acted
    arbitrarily and capriciously in adopting the flawed BiOp; and,
    third, that the FWS failed to conduct the review required by
    NEPA.14 We address their claims in Part V.
    This tortured procedural history has extended over seven
    years, and has led to five fully consolidated suits and one
    partially consolidated suit brought by various groups who use
    water supplied by the CVP and SWP, as well as to the
    completion of two extensively researched BiOps—with a
    third currently in progress. All the while, the delta smelt has
    teetered on the brink of extinction.
    We agree with Federal Defendants and the NRDC and
    reverse the district court's remand of the BiOp. We affirm the
    14
    Federal Defendants and the NRDC also appeal the district court’s
    determination that Reclamation failed to conduct review required by
    NEPA. We address this direct appeal together with appellees’ cross
    appeal.
    SAN LUIS V. JEWELL                      43
    district court’s judgment that Reclamation failed to comply
    with NEPA before implementing the FWS’s BiOp.
    II. STANDARDS OF REVIEW
    We review the district court’s ruling on summary
    judgment de novo. McFarland v. Kempthorne, 
    545 F.3d 1106
    , 1110 (9th Cir. 2008).
    Neither the ESA nor NEPA supply a separate standard for
    our review, so we review claims under these Acts under the
    standards of the APA. Bennett v. Spear, 
    520 U.S. 154
    , 174
    (1997); Oregon Natural Desert Ass’n v. Bureau of Land
    Mgmt., 
    625 F.3d 1092
    , 1109 (9th Cir. 2010); Pyramid Lake
    Paiute Tribe of Indians v. U.S. Dept. of Navy, 
    898 F.2d 1410
    ,
    1414 (9th Cir. 1990). Section 706(2) of the APA provides
    that an agency action must be upheld on review unless it is
    “arbitrary, capricious, an abuse of discretion, or otherwise not
    in accordance with law.” 
    5 U.S.C. § 706
    (2)(A). As a
    reviewing court, we “must consider whether the decision was
    based on a consideration of the relevant factors and whether
    there has been a clear error of judgment.” Citizens to
    Preserve Overton Park, Inc. v. Volpe, 
    401 U.S. 402
    , 416
    (1971), abrogated in part on other grounds as recognized in
    Califano v. Sanders, 
    430 U.S. 99
    , 105 (1977). Although our
    inquiry must be thorough, the standard of review is highly
    deferential; the agency’s decision is “entitled to a
    presumption of regularity,” and we may not substitute our
    judgment for that of the agency. 
    Id.
     at 415–16. Where the
    agency has relied on “relevant evidence [such that] a
    reasonable mind might accept as adequate to support a
    conclusion,” its decision is supported by “substantial
    evidence.” Bear Lake Watch, Inc. v. FERC, 
    324 F.3d 1071
    ,
    1076 (9th Cir. 2003). Even “[i]f the evidence is susceptible
    44                   SAN LUIS V. JEWELL
    of more than one rational interpretation, [the court] must
    uphold [the agency’s] findings.” 
    Id.
    Under the ESA, the agency must base its actions on
    evidence supported by “the best scientific and commercial
    data available.” 
    50 C.F.R. § 402.14
    (g)(8); 
    16 U.S.C. § 1536
    (a)(2). The determination of what constitutes the “best
    scientific data available” belongs to the agency’s “special
    expertise . . . . When examining this kind of scientific
    determination, as opposed to simple findings of fact, a
    reviewing court must generally be at its most deferential.”
    Baltimore Gas & Elec. Co., 
    462 U.S. at 103
    . “Absent superior
    data[,] occasional imperfections do not violate” the ESA best
    available standard. Kern Cnty. Farm Bureau v. Allen,
    
    450 F.3d 1072
    , 1080–81 (9th Cir. 2006).
    “The best available data requirement ‘merely prohibits
    [an agency] from disregarding available scientific evidence
    that is in some way better than the evidence [it] relies on.’”
    Kern Cnty. Farm Bureau, 
    450 F.3d at 1080
     (emphasis added)
    (quoting Sw. Ctr. for Biological Diversity v. Babbitt, 
    215 F.3d 58
    , 60 (D.C. Cir. 2000)). “Essentially, FWS ‘cannot ignore
    available biological information.’” 
    Id.
     at 1080–81 (quoting
    Connor v. Burford, 
    848 F.2d 1441
    , 1454 (9th Cir. 1988)).
    Thus, “insufficient . . . [or] incomplete information . . . does
    not excuse [an agency’s] failure to comply with the statutory
    requirement of a comprehensive biological opinion using the
    best information available” where there was some additional
    superior information available. Conner, 
    848 F.2d at
    1454–55.
    On the other hand, where the information is not readily
    available, we cannot insist on perfection: “[T]he ‘best
    scientific . . . data available,’” does not mean “the best
    scientific data possible.” Building Indus. Ass’n v. Norton,
    
    247 F.3d 1241
    , 1246 (D.C. Cir. 2001).
    SAN LUIS V. JEWELL                     45
    III. THE SCOPE OF THE RECORD
    Our review is limited to “the administrative record
    already in existence, not some new record made initially in
    the reviewing court.” Camp v. Pitts, 
    411 U.S. 138
    , 142
    (1973).
    If the record before the agency does not
    support the agency action, if the agency has
    not considered all relevant factors, or if the
    reviewing court simply cannot evaluate the
    challenged agency action on the basis of the
    record before it, the proper course, except in
    rare circumstances, is to remand to the agency
    for additional investigation or explanation.
    The reviewing court is not generally
    empowered to conduct a de novo inquiry into
    the matter being reviewed and to reach its
    own conclusions based on such an inquiry. . . .
    The factfinding capacity of the district
    court is thus typically unnecessary to judicial
    review of agency decisionmaking.
    Florida Power & Light Co. v. Lorion, 
    470 U.S. 729
    , 744
    (1985). See also Citizens to Preserve Overton Park, 
    401 U.S. at
    419–20.
    There is a danger when a reviewing court goes beyond the
    record before the agency. “When a reviewing court considers
    evidence that was not before the agency, it inevitably leads
    the reviewing court to substitute its judgment for that of the
    agency.” Asarco, Inc. v. EPA, 
    616 F.2d 1153
    , 1160 (9th Cir.
    1980). See Sw. Ctr. for Biological Diversity v. U.S. Forest
    46                  SAN LUIS V. JEWELL
    Serv., 
    100 F.3d 1443
    , 1450 (9th Cir. 1996) (“Judicial review
    of an agency decision typically focuses on the administrative
    record in existence at the time of the decision and does not
    encompass any part of the record that is made initially in the
    reviewing court.”). Accordingly, we do not review “the
    evidence to determine the correctness or wisdom of the
    agency’s decision . . . even if the court has also examined the
    administrative record.” Asarco, 
    616 F.2d at 1160
    . If the
    reviewing court cannot find substantial evidence in the
    record, it should “not compensate for the agency’s dereliction
    by undertaking its own inquiry into the merits,” 
    id.,
     but
    should remand to the agency for further proceedings, see INS
    v. Ventura, 
    537 U.S. 12
    , 16 (2002).
    “We have, however, crafted narrow exceptions to this
    general rule.” Lands Council v. Powell, 
    395 F.3d 1019
    , 1030
    (9th Cir. 2005). As we have explained,
    [w]e allow expansion of the administrative
    record in four narrowly construed
    circumstances: (1) supplementation is
    necessary to determine if the agency has
    considered all factors and explained its
    decision; (2) the agency relied on documents
    not in the record; (3) supplementation is
    needed to explain technical terms or complex
    subjects; or (4) plaintiffs have shown bad faith
    on the part of the agency.
    Fence Creek Cattle Co. v. U.S. Forest Serv., 
    602 F.3d 1125
    ,
    1131 (9th Cir. 2010). Keeping in mind the Supreme Court’s
    concerns with reviewing court factfinding, we have
    approached these exceptions with caution, lest “the exception
    SAN LUIS V. JEWELL                      47
    . . . undermine the general rule.” Lands Council, 
    395 F.3d at 1030
    .
    We have serious concerns that the district court failed to
    observe these rules. First, the district court appointed four
    experts to aid it in understanding the technical and scientific
    aspects of the BiOp. These experts were appointed consistent
    with Federal Rule of Evidence 706. See supra Note 13.
    Having read the BiOp, we are sympathetic to the district
    court’s need for a scientific interpreter. No party has objected
    on appeal to the district court’s appointments, and we can see
    no reasonable objection to the use of experts to explain the
    highly technical material in the BiOp.
    The district court, however, did not limit itself to the
    court-appointed experts. Over the vigorous objection of the
    appellants, the court admitted multiple declarations from
    multiple experts hired by the appellees, even though the
    party-appointed experts addressed many of the same issues
    being addressed by the court-appointed experts. By the
    government’s count—which we have not sought to verify,
    although we have examined the declarations in the
    record—the district court admitted more than forty expert
    declarations from the appellees; once the court denied the
    appellant’s motion to exclude the declarations, the appellants
    submitted their own experts’ declarations. Yet, we cannot see
    what the parties’ experts added that the court-appointed
    experts could not have reasonably provided to the district
    court. See Animal Def. Council v. Hodel, 
    840 F.2d 1432
    ,
    1437 (9th Cir. 1988) (plaintiff failed to show why the district
    court needed to go outside the administrative record). The
    effect of this was, predictably, to create a battle of the
    experts. Moreover, it gave the proceedings in the district
    court the appearance that the administrative record was open
    48                  SAN LUIS V. JEWELL
    and that the proceedings were a forum for debating the merits
    of the BiOp. See Ariz. Cattle Growers’ Ass’n v. U.S. Fish &
    Wildlife, 
    273 F.3d 1229
    , 1245 (9th Cir. 2001) (“Considering
    evidence outside the record would render the extraordinarily
    complex consultation process . . . meaningless.”). Just as we
    will not allow the agency to supply post-hoc rationalizations
    for its actions, so “post-decision information . . . may not be
    advanced as a new rationalization either for sustaining or
    attacking an agency’s decision.” Sw. Ctr. for Biological
    Diversity, 
    100 F.3d at 1450
    . As the Court cautioned, “[w]hen
    specialists express conflicting views, an agency must have
    discretion to rely on the reasonable opinions of its own
    qualified experts even if, as an original matter, a court might
    find contrary views more persuasive.” Marsh v. Ore. Natural
    Res. Def. Council, 
    490 U.S. 360
    , 378 (1989).
    Even a quick review of the district court’s opinion shows
    that the appearance of an open record was the reality. The
    district court relied extensively on the declarations of the
    parties’ experts-as-advocates as the basis for rejecting the
    BiOp. See, e.g., San Luis & Delta-Mendota, 
    760 F. Supp. 2d at
    877–79, 881–84, 889–90, 894–97, 903–07, 912, 922. In
    places, the district court pits the experts against each other
    and resolves their contrary positions as a matter of scientific
    fact. E.g., San Luis & Delta-Mendota, 
    760 F. Supp. 2d at 884
    , 904–07. In effect, the district court opened the BiOp to
    a post-hoc notice-and-comment proceeding involving the
    parties’ experts, and then judged the BiOp against the
    comments received. The ESA consultation process is not a
    rulemaking proceeding, but a request from one agency for the
    expertise of a second agency. Although we may review each
    of those proceedings under the APA, the agency’s obligations
    under each is slightly different, and we must account for that
    difference in our review.
    SAN LUIS V. JEWELL                      49
    Our opinion in Asarco v. EPA addressed the question of
    using experts in a technical case and is on point here. In that
    case, the district court had a technical matter before
    it—involving a 1,000 foot stack at a smelter—and permitted
    the parties to call their experts. The court held four days of
    hearings in which at least ten witnesses testified. We held
    that some of the testimony, mainly from experts who
    provided “background material” on the smelter’s operations,
    was appropriate; the rest of it was not appropriate, even if it
    came from experts and “served some marginal purpose”:
    Most of the expert testimony, however, should
    not have been admitted or at least not have
    been considered for the purpose of judging the
    wisdom of the EPA’s stack-testing
    requirement. This technical testimony was
    plainly elicited for the purpose of determining
    the scientific merit of the EPA’s decision.
    Although the testimony may have served
    some marginal purpose in allowing the district
    court to evaluate the EPA’s court of inquiry,
    we can only conclude that the extent of the
    scientific inquiry undertaken at trial
    necessarily led the district court to substitute
    its judgement for that of the agency.
    
    616 F.2d 1155
    , 1160–61 (9th Cir. 1980).
    The district court similarly overstepped its bounds here.
    Because we review the court’s judgment de novo, however,
    we can confine our own scope of review to the administrative
    record, plus that evidence that satisfies the standards we have
    set forth here. See Dow Agrosciences v. Nat’l Marine
    Fisheries Serv., 
    707 F.3d 462
    , 469 (4th Cir. 2013) (confining
    50                   SAN LUIS V. JEWELL
    review to the administrative record and disregarding an
    affidavit submitted to the district court). We will consider the
    BiOp and any other evidence in the record submitted by the
    parties that the FWS considered in making its decision. We
    will also consider the testimony of the four experts the district
    court appointed pursuant to Rule 706, as to whom there is no
    objection.
    IV. MERITS OF THE BiOp
    Before we consider the challenges to the BiOp, we have
    some preliminary observations. First, the BiOp is a bit of a
    mess. And not just a little bit of a mess, but, at more than 400
    pages, a big bit of a mess. And the FWS knew it. In
    November 2008, shortly before the FWS submitted its final
    draft, the California Department of Water Resources
    commented on a portion of the FWS’s draft. Under the title
    “The Document is Confusing and Disorganized,” the DWR
    advised that “the document is especially unrefined. The text
    is often out of logical order . . . , many actions are fairly
    vague, and the document is unpolished.” Some portions,
    DWR wrote, were “largely unintelligible.” The FWS also
    submitted its draft to a peer review panel, coordinated by an
    outside engineering firm. One of the questions the FWS
    asked the panel was whether the BiOp was “organized in a
    manner that is clear, concise and complete (i.e., is it
    understandable)?” The panel pulled no punches and
    responded as follows: “The Panel’s response to this question
    is ‘no.’ The version of the [Effects Analysis] provided to the
    Panel was a draft and had not been adequately edited for
    general organization, consistency across sections in how
    analyses were described and reported, and for redundancies.”
    The bottom line was that “most readers would have a difficult
    time.”
    SAN LUIS V. JEWELL                              51
    Both the California DWR and the peer review panel
    commented on the FWS’s imposing schedule for issuing the
    BiOp. DWR observed that the “FWS was under an
    exceptionally difficult deadline to get this document in.” In
    a comment letter sent from the DWR to Reclamation just two
    weeks before the deadline, the DWR reflected on the
    pressures the FWS labored under: “Our concerns with the
    Draft [BiOp] are extensive but are correctable before the
    December 15 court ordered [deadline] for its finalization. We
    are willing to work closely with the FWS to address these
    concerns quickly. . . .” And the peer review panel
    complained that its own “review was conducted in a four-day
    period under a tight schedule.” See Ass’n of Pac. Fisheries v.
    EPA, 
    615 F.2d 794
    , 811 (9th Cir. 1980) (“The Agency itself
    recognized that its data collection was not as thorough as it
    otherwise would have been: ‘The time constraints imposed by
    the statutory deadlines precluded the Agency from
    conducting an exhaustive sampling program.’”). This
    challenging deadline was not the fault of the agency, but was
    set by the same district court that would later hold that the
    FWS’s rushed BiOp was arbitrary and capricious. See San
    Luis & Delta-Mendota, 506 F. Supp. at 322 (ordering the
    FWS to produce a revised BiOp in just nine months—a
    deadline that would later be extended by three months to give
    the FWS just one year to produce a new BiOp).15
    15
    One of the ironies of the district court’s deadlines is that the FWS had
    less time to produce its opinion than either the district court or we will
    have had to review it: The 2008 BiOp was issued in December 2008. The
    district court’s summary judgment decision issued almost two years to the
    day, in 2010. This opinion issues nearly three years later.
    The concerns in adhering to deadlines is familiar to courts who must
    occasionally rush to judgment. Justice Powell once bemoaned the
    problems arising from deciding cases “late in the Term” when the Court
    52                      SAN LUIS V. JEWELL
    We concur in these assessments. The BiOp is a jumble of
    disjointed facts and analyses. It appears to be the result of
    exactly what we would imagine happens when an agency is
    ordered to produce an important opinion on an extremely
    complicated and technical subject matter covering multiple
    federal and state agencies and affecting millions of acres of
    land and tens of millions of people. We expect that the
    document was patched together from prior documents,
    assembled quickly by individuals working independent of
    each other, and not edited for readability, redundancies, and
    flow. It is a ponderous, chaotic document, overwhelming in
    size, and without the kinds of signposts and roadmaps that
    even trained, intelligent readers need in order to follow the
    agency’s reasoning. We wonder whether anyone was
    ultimately well-served by the imposition of tight deadlines in
    a matter of such consequence.16 Deadlines become a
    substantive constraint on what an agency can reasonably do.
    In this case, the FWS not only had to write and compile the
    report—a substantial task in and of itself—but was under
    pressure to, among other things, produce a reliable population
    estimate of the delta smelt. Kempthorne, 
    506 F. Supp. 2d at 373
     (faulting the 2005 BiOp for failing to produce such an
    estimate, and noting that “[t]he viability of Delta smelt has
    been under scrutiny for over ten years. No party has shown
    was precluded by its own deadlines from “an opportunity for more
    thorough consideration of the basic principles at risk.” Robbins v.
    California, 
    453 U.S. 420
    , 435–36 (1981) (Powell, J., concurring in the
    judgment). Robbins was overruled the following Term in United States
    v. Ross, 
    456 U.S. 798
    , 824 (1982).
    16
    We recognize that the ESA itself imposes deadlines for a consulting
    agency to produce a BiOp, but those deadlines may be extended by
    consent of the requesting agency or the concerned applicant. See
    
    16 U.S.C. § 1536
    (b)(1), (2). Here, the district court fixed the deadline.
    SAN LUIS V. JEWELL                      53
    that producing a reliable population estimate is scientifically
    unfeasible”). Such scientific tasks may not be as well suited
    to deadlines as producing written copy; the final product will
    necessarily reflect the time allotted to the agency. The FWS
    is currently preparing its third BiOp, again under the orders
    of the district court and on the district court’s deadlines.
    Although we ultimately conclude that we can discern the
    agency’s reasoning and that the FWS’s 2008 BiOp is
    adequately supported by the record and not arbitrary and
    capricious, we also recognize that Reclamation has
    continuing responsibilities under CVP and SWP and that this
    is likely not the last BiOp that the FWS will issue with
    respect to the delta smelt, nor is this the last legal challenge
    that we will hear. Future analyses should be given the time
    and attention that these serious issues deserve.
    A. The 2008 BiOp’s Reliance on Raw Salvage Figures to Set
    the Upper and Lower OMR Flow Limits Was Not
    Arbitrary and Capricious
    Under normal pumping operations, enough water is
    pumped from the OMR that the river’s flow reverses. BiOp
    at 159–60. As vast quantities of water are pumped from the
    river, smelt and other fish are entrained in the pumps, where
    they are captured and counted in fish salvage facilities. 
    Id.
    Not all smelt are salvaged, however, as juvenile smelt smaller
    than 20 mm (0.79 inches), smelt still in the larval stage, and
    some percentage of adult delta smelt, are killed by the pumps.
    BiOp at 338. The prospects for salvaged smelt are also grim,
    as smelt rarely survive the salvage process, id.; up to sixty
    percent of the smelt population is lost each year at the
    pumping plants, BiOp at 210. Unsurprisingly, the 2008 BiOp
    found that as the OMR flows became increasingly negative,
    the entrainment risk and accompanying population loss
    54                     SAN LUIS V. JEWELL
    increased accordingly, thereby threatening the smelt
    population’s continuing viability. BiOp at 163.
    To mitigate this effect, the BiOp RPA imposed pumping
    limits expressed in terms of negative OMR flows,17 ranging
    from !1,250 cubic feet per second (cfs) to !5,000 cfs. BiOp
    at 280. Which limit is applicable is determined by the
    location of the smelt population, water turbidity,18 and a range
    of other factors. BiOp at 280. In determining the OMR flow
    limits, the FWS relied, in part, on the number of delta smelt
    salvaged from the fish screening facilities. Although it
    acknowledged that the number of smelt salvaged only
    represents “a small percentage of the actual number
    entrained,” and “is not a good estimate of actual delta smelt
    mortality through entrainment,” BiOp at 338, the FWS relied
    on this information because “[d]ata on the salvage of delta
    smelt is typically used to provide an index of entrainment into
    the diversion pumps,” BiOp at 145.
    The OMR flow limit has a great practical significance, not
    merely to the delta smelt but to Californians, as it represents
    the ultimate limit on the amount of water available to sustain
    California’s millions of urban and agricultural users.
    Appellees challenge the !5,000 cfs upper limit on OMR
    flows, claiming that the FWS based its calculation of the flow
    limit solely on information contained in two figures that show
    17
    Actions 1 and 2 of the RPA protect adult delta smelt migrating
    upstream in winter months to spawn, and Action 3 protects larval and
    juvenile delta smelt in the spring after they hatch. BiOp at 280, 282.
    18
    Water turbidity is the measurement of how much sediment or foreign
    particles are suspended in the water.
    SAN LUIS V. JEWELL                       55
    a significant increase in the number of smelt salvaged at
    approximately !5,000 cfs: Figures B-13 and B-14. See BiOp
    at 347, 350. These figures, appellees assert, failed to justify
    the !5,000 cfs limit because the number of delta smelt
    salvaged (raw salvage) was not adjusted for the smelt’s
    estimated population for that year (normalized). Appellees’
    objection to the BiOp’s use of raw salvage data, rather than
    normalized data, in calculating appropriate OMR flow limits
    is essentially an omitted variable bias argument; appellees
    assert that the number of smelt salvaged in a year is highly
    influenced by the total population of smelt that year, and that
    therefore the BiOp’s failure to account for this relation
    renders its calculated flow limits unreliable. Put another way,
    according to appellees, when there are more smelt in the Bay-
    Delta, more smelt are salvaged. Any apparent relationship
    between OMR flows and smelt salvage, therefore, may
    actually be a relationship between smelt population size and
    smelt salvage. Failing to account for this will skew, if not
    invalidate entirely, the analysis.
    The district court agreed, finding that “[t]he use of raw
    salvage data, as opposed to salvage data scaled to population
    size, is problematic because raw salvage figures do not
    account for the size (or relative size) of the smelt population.”
    San Luis & Delta-Mendota, 
    760 F. Supp. 2d at 889
    . The
    district court further found that “the use of normalized
    salvage data rather than gross salvage data is the standard
    accepted scientific methodology.” 
    Id.
     It concluded that the
    FWS’s use of raw salvage data in Figures B-13 and B-14 to
    determine restrictions on OMR flows was “scientifically
    unacceptable.” 
    Id. at 891
    . Because the FWS failed to use the
    best available scientific data, its !5,000 cfs flow limit in
    Actions 1, 2 and 3 was arbitrary and capricious. Id.; see 
    id.
     at
    891–94.
    56                      SAN LUIS V. JEWELL
    These objections, however, suffer from several problems.
    First, the FWS appropriately relied on Figures B-13 and B-14
    to justify its !5,000 cfs flow limits. In Figures B-13 and B-
    14, the FWS acknowledged the uncertainty inherent to
    modeling the relation between OMR flows and smelt and
    chose a conservative model, a choice that is within the FWS’s
    discretion to make. See Nw. Coal. for Alts. to Pesticides v.
    EPA, 
    544 F.3d 1043
    , 1050 (9th Cir. 2008). Second, the
    !5,000 cfs flow limit prescribed in the RPA was not solely
    determined from Figures B-13 and B-14, and therefore flaws
    in those figures do not necessarily doom the BiOp’s
    conclusions. Third, the BiOp’s OMR flow limits work in
    tandem with the incidental take statement (ITS), which
    accounts for population-level impacts.
    That the FWS could have done more in determining OMR
    flow limits is uncontroverted. This, however, is not to say
    that the FWS acted arbitrarily and capriciously; we hold,
    contrary to the district court, that the FWS’s OMR flow limits
    are supported by substantial evidence.
    1. The FWS’s choice of a more conservative model to
    calculate flow limits in Figures B-13 and B-14 was
    supported by substantial evidence
    Figure B-13 in the BiOp19 is a graph showing the
    relationship between salvaged adult delta smelt and the OMR
    flow, measured in cfs. The graph shows a positive correlation
    between salvaged smelt and the reverse flow of the river.
    That is, the greater the water pumped through the Jones and
    Banks pumping stations, the greater the count of smelt
    19
    Figures B-13 and B-14 are reproduced in the district court’s published
    opinion. Kempthorne, 
    506 F. Supp. 2d at
    886–87.
    SAN LUIS V. JEWELL                             57
    salvaged at those stations. The FWS noted that the graph is
    upward sloping and linear in the lower half of the curve. At
    about !5,000 cfs there is a “break” in the data,20 and for flows
    more negative than !5,000 cfs (meaning more water exported
    from the Bay-Delta), the upward slope increases at an
    increasing rate. The FWS sought to verify whether the break
    in the data was actual. It conducted additional analyses of the
    data to verify that there was not a natural break at any other
    point and that any error in the OMR flow rates or salvage
    could not have caused the break. BiOp at 349–51. The FWS
    concluded that with “flows more negative than !1683,
    salvage increased.” BiOp at 351.
    The FWS stated that “[a] major assumption of this
    analysis is that as the population of Delta smelt declined, the
    number of fish at risk of entrainment remained constant.”
    BiOp at 349. What B-13 did was compare actual salvage
    numbers with OMR flow. What the FWS did not do—and
    what the appellees and the district court claim the FWS
    should have done—was prepare an additional figure in which
    it compared “normalized” salvage numbers with OMR flows.
    Normalized salvage would be the measure of the salvaged
    smelt divided by the total population of smelt,21 effectively
    20
    The break in the data in B-13 appears to span about !3,000 cfs to just
    under !6,000 cfs. BiOp at 348. The FWS did not attempt to quantify the
    break; it simply observed that there “appears to be a ‘break’ in the dataset
    at approximately !5,000 OMR.” BiOp at 347.
    21
    Part of the district court’s frustration may be that, to date, no one has
    been able to produce a reliable population estimate for the delta smelt. In
    2007 when the district court sent the 2005 BiOp back to the FWS, it
    commented that
    58                       SAN LUIS V. JEWELL
    yielding figures showing what percentage of smelt each year
    were salvaged at the pumps.
    In fact, the FWS itself had stated that it could verify its
    conclusion “by normalizing the salvage data by the estimated
    population size based on the [Fall Midwater Trawl] data.”
    BiOp at 349. The peer review had similarly suggested
    normalizing the data:
    The Panel suggests that the use of predicted
    salvage of adult smelt should be normalized
    for population size. . . . One way to normalize
    The viability of Delta smelt has been under
    scrutiny for over ten years. No party has shown that
    producing a reliable population estimate is scientifically
    unfeasible. . . . Without population estimates, it is
    arbitrary for the agency to conclude that project
    operations will not result in jeopardy simply because
    the projects will take relatively fewer smelt than they
    did in the past, in the fact of the undisputed fact that the
    smelt population has been declining steadily in recent
    years. Failing to incorporate any information about
    smelt population abundance into the setting of the take
    limits is a fundamental failure rendering the BiOp
    arbitrary and capricious.
    Kempthorne, 
    506 F. Supp. 2d at 373
    . Despite the court’s warning, the
    FWS did not conduct a population study, nor did it explain why one could
    not be conducted. Yet, the FWS, its peer reviewers, and the district
    court’s experts suggested that there were proxies for population (such as
    the FMWT count) available, even if a strict population count was not.
    Sometimes we have to read the shadows to discern the reality behind
    it: Nearly twenty years after the smelt were declared endangered, we know
    the smelt population is continuing to decline and is imperiled, but still no
    one knows how many there are. It must tell us something about the
    difficulties that inhere in trying to count migrating, two-inch fish.
    SAN LUIS V. JEWELL                             59
    salvage for population size is to divide by the
    previous fall Midwater Trawl (MWT) index.
    A similar regression model to the one fitted to
    salvage would relate the normalized salvage
    to Old and Middle River (OMR) flows. . . .
    Expressing salvage as a normalized index may
    help remove some of the confounding of the
    temporal trends during the baseline period
    ....
    As the district court’s experts acknowledged, the FWS faces
    significant practical challenges in setting OMR flow rates to
    minimize delta smelt entrainment. For example, day-to-day
    variations in OMR flows and “noise” in smelt sampling22
    used to establish abundance and distribution of the delta smelt
    are significant confounding factors in determining
    appropriate OMR flow rates, as is the distribution of the delta
    22
    “Noise” is a statistical term that refers to the unexplained randomness
    or variation that is found in a sample. It is of particular concern when
    statistical samples are small. As Dr. Quinn explained:
    [W]hat are the uncertainties in the population estimates
    themselves, and might there be shifting levels of
    accuracy as population levels change? . . . [It] is
    certainly true [that population growth rate is an
    appropriate and reliable measure of the population
    increases and decreases from year to year], if it is
    known without error but what are the assumptions
    about sampling? That is, as smelt become increasingly
    scarce, does their overall distribution become ‘thinner
    all around’ or is it ‘patchy’, and how might such
    changes influence the reliability of data from different
    surveys of abundance? In general, ‘noisy’ data make it
    more difficult to detect underlying patterns, even if the
    patterns are genuine.
    60                  SAN LUIS V. JEWELL
    smelt population in relation to the pumps. BiOp at 165, 331,
    353–55. A lack of real-time information and variations
    inherent to environmental systems make precision virtually
    impossible. BiOp at 165, 331, 353–55. Yet, as even the
    district court recognized, population numbers of the delta
    smelt are perilously low, San Luis & Delta-Mendota, 
    760 F. Supp. 2d at 866
    , and entrainment by the pumping plants has
    a “sporadically significant influence on population
    dynamics,” 
    id. at 877
     (emphasis added).
    In such circumstances, the FWS’s decision to use raw
    salvage data rather than population-adjusted salvage data
    reasonably protects the delta smelt population without regard
    to year-by-year fluctuation in population size. The BiOp
    notes that this decision was motivated by a concern for the
    absolute number of smelt entrained in the pumps, not the
    relative number of smelt: “The current population cannot
    tolerate direct mortality through adult entrainment at levels
    approaching even ‘moderate’ take as observed through the
    historic record of recent decades.” BiOp at 287. Thus, the
    RPA is designed to “reduce entrainment of pre-spawning
    adult delta smelt during December to March” and to
    “[m]inimize the number of larval delta smelt entrained at the
    facilities” by controlling OMR flow from March to June.
    BiOp at 280, 357. The analytical approach preferred by
    appellees and the district court is best gauged to measure the
    number of smelt entrained at the pumps relative to the
    population size. This may be a more accurate reflection of
    the relative impact of OMR flows on the smelt population,
    but it is not tailored to protect the maximum absolute number
    of individual smelt, as the BiOp’s approach is; the process of
    adjusting raw salvage for the smelt population size results in
    SAN LUIS V. JEWELL                             61
    normalized numbers, but it does so at the potential cost of
    minimizing the impact of each individual smelt lost.23
    Our deference to agency determinations is at its greatest
    when that agency is choosing between various scientific
    models, as the FWS did in the present instance. See Nw.
    Coal. for Alts. to Pesticides, 
    544 F.3d at 1050
    . Facing great
    measurement uncertainty and a smelt population whose
    existence is threatened, the FWS chose to be conservative in
    setting the flow limits in Actions 1, 2, and 3. This choice was
    well within its discretion; the Supreme Court has held that an
    agency may choose to “counteract the uncertainties” inherent
    in its scientific analyses by “overestimat[ing]” known
    parameters without being unreasonable, Baltimore Gas &
    Elec. Co., 
    462 U.S. at 103
    , and we have upheld an agency’s
    reliance on models that “yield conservative data because the
    23
    Appellee-Metropolitan Water District uses “one of the data points
    located at about !5,000 cfs on Figure B-13” for the year 2000 as an
    example. An unusually high smelt salvage was observed in 2000, but, as
    Appellee indicates, the smelt population was also higher than usual in that
    year. Appellee argues that because “[i]t is to be expected that more fish
    would be salvaged in a year in which the population was extremely large,”
    the raw salvage number should be normalized for total smelt population.
    Accepting appellee’s argument that salvage rates should be normalized,
    the year 2000 would have actually represented a below average
    (normalized) salvage. Yet, it is undisputed that an extraordinary number
    of smelt were salvaged in that year.
    A normalized analysis of smelt salvage counts the year 2000 as a
    below-average year, while an analysis of raw smelt salvage counts the
    year 2000 as an above-average year. The FWS’s choice of analysis
    influences whether it is the OMR flow’s relative or absolute impact on
    smelt population that is prioritized. Thus, the quality of the statistical
    method is not the only relevant factor at play, as the district court
    erroneously concluded: the BiOp’s choice of one model over the other
    implicates significantly differing management policies.
    62                       SAN LUIS V. JEWELL
    models incorporate the higher of [known potential values] in
    assessing the overall risk,” Nw. Coal. for Alts to Pesticides,
    
    544 F.3d at 1050
    . Likewise, we give the FWS great deference
    in its choice of scientific tools, and, in these circumstances,
    hold that the FWS did not act arbitrarily or capriciously in
    choosing an analytical tool that resulted in greater protections
    for the imperiled smelt population.24
    24
    The district court relied substantially on the testimony of its experts,
    Dr. Andre Punt and Dr. Thomas Quinn, in concluding that the BiOp’s
    reliance on Figures B-13 and B-14 was “scientifically unacceptable.” San
    Luis & Delta-Mendota, 
    760 F. Supp. 2d at 891
    . But these experts present
    a more nuanced view of the FWS’s use of Figures B-13 and B-14. The
    results confirm what the FWS had already said: that additional analyses
    using normalized data from B-13 could have informed the FWS’s
    conclusions. The experts noted that B-13 was a proper measure, although
    not the only, and perhaps not the preferable, measure. The experts also
    testified as to the need for the FWS to set some parameters on OMR
    flows, and the difficulty in figuring out precisely where the parameters
    should be.
    In response to the district court’s question whether it was
    “unreasonable for FWS to rely in part on the information represented in
    figure B-13,” Dr. Quinn answered that he did “not regard it as
    unreasonable for FWS to have relied in part on this figure and the data
    behind it.” But he cautioned that “[t]o rely entirely on it would, however,
    have neglected the complexities of the issue . . . . Both the number of fish
    salvaged and the proportion salvaged . . . are relevant, in my view, as are
    other kinds of information.” Dr. Punt had a similar reaction: “it was
    unreasonable . . . to have only relied on the information in Figures B-13
    and B-14 rather than on an analysis in which salvage is expressed relative
    to population size.” (emphasis added).
    Moreover, although both experts had been critical of the FWS’s
    failure to run the additional numbers, both were cautious about what the
    normalized data might have shown, whether any hard conclusions could
    be drawn from any data set, and even whether normalized data would be
    preferable to the non-normalized data produced. Dr. Quinn acknowledged
    that even if the FWS had normalized the data in B-13, “plotting flow
    SAN LUIS V. JEWELL                              63
    against a salvage index might not fully capture the risk to the population.”
    With respect to what B-13 showed, Dr. Quinn cautioned that it was
    “unwise to overestimate the precision” of the data. He was not convinced
    that there was a “break” in the data, “though [his] basis for saying so [was]
    more intuitive than statistical.” He “emphasize[d] that any point value has
    a measure of arbitrariness. If !5000, then why not !4900 cfs? Given the
    many sources of variation in the data, it strikes me as necessary to set
    limits even though there may not be strong statistical basis for a particular
    figure rather than a slightly different one.” He concluded that although
    “the validity of [FWS’s] specific flow regimes [was] undermined by the
    incomplete analyses that were done on the available data,” it was
    “appropriate for the FWS to have some leeway in making decision and
    setting limits in their efforts to protect and recover listed species.” Dr.
    Punt went one step further, recognizing the advantage of non-normalized
    data: B-13, as it is produced in the BiOp, would be justified if “any
    entrainment, no matter how small relative to the total population size, has
    long-term consequences for the population size of delta smelt.”
    These responses from the experts question the FWS’s failure to
    expand its analysis and to normalize the data underlying B-13. Had it
    done so, the experts concluded, the FWS would have had a more complete
    sense of the relationship between OMR flow and salvage, although it is far
    from clear that that study would have affected the FWS’s conclusions.
    What the experts’ testimonies do not support is the district court’s
    overstated conclusion that the FWS’s “use of raw salvage in the analyses
    depicted in Figures B-13 and B-14 is scientifically unacceptable” or that
    “such metrics are meaningless as management tools.” San Luis & Delta-
    Mendota, 
    760 F. Supp. 2d at 891
    . Were we only evaluating the experts’
    opinion on the BiOp, we would face a difficult question as to the
    continuing validity of this aspect of the BiOp: it is clear that these two
    experts believed the BiOp to have fallen short in this analysis, although as
    Dr. Punt indicates, persuasive justifications exist for the BiOp’s reliance
    on non-normalized data. It is less clear, however, that the BiOp—even as
    seen through the eyes of Drs. Punt and Quinn—would be rendered
    arbitrary and capricious by a sole reliance on Figures B-13 and B-14. We
    need not reach this question, as we accept the opinions of the district
    court’s experts only insofar as they are persuasive and informative,
    and—as will be subsequently described—we independently conclude that
    64                     SAN LUIS V. JEWELL
    2. The BiOp’s determination of OMR flow limits was
    influenced by more than Figures B-13 and B-14
    The district court’s experts concluded that it was the
    BiOp’s apparent exclusive reliance on Figures B-13 and B-14
    that was problematic: as they acknowledged, the figures
    could be useful in tandem with other analyses and data. The
    district court therefore based its invalidation of the !5,000 cfs
    OMR flow limit on its finding that the limit “depend[s] so
    heavily” on Figures B-13 and B-14. San Luis & Delta-
    Mendota, 
    760 F. Supp. 2d at 968
    . After conducting an
    independent review of the record, however, we hold that the
    BiOp’s determination of OMR flow limits was sufficiently
    influenced by several other population-level analyses in
    addition to Figures B-13 and B-14. Together with Figures B-
    13 and B-14, these analyses provide substantial evidence that
    supports the BiOp’s !5,000 cfs OMR flow limit.
    First, the BiOp expressly notes that it employed multiple
    analyses in determining the OMR flow limits, stating with
    regards to Actions 1 and 2 that “recent analyses indicate that
    cumulative adult entrainment and salvage are lower when
    OMR flows are no more negative than !5,000 cfs in the
    December through March period.” BiOp at 281 (emphasis
    added). Although the BiOp fails to specify exactly which
    studies it relies on,25 at least one of these studies is
    the BiOp does not exclusively rely on Figures B-13 and B-14 in
    determining the OMR flow limits.
    25
    The BiOp should have been more explicit in describing exactly which
    studies it used in its analysis. Had the BiOp been similarly vague
    throughout its analysis, its lack of specificity may have presented a
    problem. Here, however, the BiOp has provided sufficient support for its
    conclusions.
    SAN LUIS V. JEWELL                                 65
    contextually apparent: a 2008 study by Wim J. Kimmerer,
    Losses of Sacramento River Chinook Salmon and Delta Smelt
    to Entrainment, San Francisco Estuary and Watershed
    Science (hereinafter “Kimmerer 2008”). Kimmerer’s study
    was referred to throughout the BiOp, and his data was
    reproduced in a chart estimating adult entrainment. BiOp at
    281. The Kimmerer 2008 study quantified the relationship
    between population losses and OMR flows between 1995 and
    2006, concluding—consistent with Figure B-14—that as
    OMR flow becomes more negative, delta smelt population
    losses increase. Moreover, in Figure E-4, the FWS read
    Kimmerer 2008 to show that when OMR flows are more
    negative than !5,000 cfs—the “break” observed in Figure B-
    13—population loss typically exceeds 10 percent. BiOp at
    250 (Figure E-4). Figure E-4 shows a strong correlation
    between flows more negative than !5,000 cfs and high smelt
    population losses, supporting Figure B-13’s “break.” See
    BiOp at 250; see also BiOp at 213 (discussing Figure E-4).26
    26
    Even if Figure E-4’s correlation were less apparent, not all analyses
    will yield clear “change points,” and therefore the fact that none is
    immediately apparent in a study does not mean that the study cannot
    support an agency’s specifically defined limits; such a holding would
    effectively prohibit an agency from setting exact limits in any
    circumstance in which a clear change point did not emerge from the data.
    In the present situation, Kimmerer 2008 and Figure E-4 present a
    reasonable justification for a !5,000 cfs limit, which does appear to be an
    approximate point of some significance. That Kimmerer 2008 may also
    provide a reasonable justification for a !4,999 or a !5,001 limit does not
    make the FWS’s policy choice arbitrary and capricious, especially given
    the significant deference owed to the agency in our review. To do so
    smacks more of strict scrutiny than arbitrary and capricious review under
    the APA and ESA.
    Even were the range of the limit justified by Kimmerer 2008
    substantially greater than this, and it most likely is, it is not appropriate for
    66                      SAN LUIS V. JEWELL
    Second, the BiOp was more explicit in describing its
    bases for determining the !5,000 cfs limit for Action 3,
    stating that “[t]he OMR flows associated with the
    protectiveness criteria defined above have been derived from
    particle tracking modeling27 with the input assumptions
    defined below.” BiOp at 360. Because Action 3 protects
    larval and juvenile delta smelt specifically, which are
    generally smaller than 20 mm (0.79 inches)—too small for
    salvage facility tracking—particle tracking modeling was
    necessary to estimate Action 3 entrainment. BiOp at 282.
    The district court appears to have misunderstood the
    distinction between the analyses supporting the Action 1 and
    2 limits and those supporting the Action 3 limits. San Luis &
    Delta-Mendota, 
    760 F. Supp. 2d at 922
     (finding that the FWS
    derived the !5,000 cfs limit for Action 3 from the district
    court’s previous order, from a non-linear DWR model, and
    from Figure B-13, failing to mention the particle tracking
    modeling). The particle tracking modeling results are
    reflected in the BiOp’s figure B-16, and demonstrate a low
    risk of entrainment as long as OMR flows remain below
    !2,000 cfs, increasing to a 20 percent risk at !3,500 cfs.
    BiOp at 366–67. The high entrainment at more negative
    flows would potentially place at risk 80 percent of all
    larval/juvenile smelt over the period of the approximately
    four months that Action 3 is under effect. BiOp at 366. As
    the OMR flow approaches !5,000 cfs, the modeling predicts
    that smelt entrainment will near 100 percent at multiple
    a reviewing court to second guess the agency’s scientific judgments in
    such matters where, as is the case here, the agency’s determination
    appears to fall within the data-justified range.
    27
    Particle tracking modeling simulates larval fish by inserting neutrally
    buoyant particles into a model domain with flow conditions.
    SAN LUIS V. JEWELL                     67
    stations. BiOp at 367. Given such findings, the FWS did not
    act unreasonably in setting the OMR flow limits; the particle
    tracking modeling completed for Action 3 provides
    independent support for the OMR limits.
    Third, the DWR recommended to the FWS that it set the
    parameters at !5,000 cfs. In its informal comments to the
    FWS, it recommended that “[t]he justification for using a
    range of !5000 to !1250 cfs OMR rather than the !5000 cfs
    the FWS, USBR, and DWR proposed to the District Court
    last summer should be more clearly explained.” In formal
    comments submitted to Reclamation just two weeks before
    the BiOp was due, the DWR criticized the RPA Component
    1 (Action 2) because it “call[ed] for much more restrictive
    Old and Middle River Flows than supported by the best
    available data to reasonably minimize entrainment of adult
    delta smelt.” As the DWR noted, the “proposed flows range
    from !1,250 cfs to !5,000 cfs. The current set flow of
    !5,000 cfs should be used except in specific circumstances
    relating to fish survey and salvage data, because it is better
    supported by the available scientific information.” (emphasis
    added) The DWR added that
    [i]n DWR’s October 16 submittal we
    presented the monthly analysis of Old and
    Middle River (OMR) flows and salvage of
    adult delta smelt that was also provided to
    Judge Wanger in 2007. This analysis appears
    to have been ignored by the FWS even though
    the analysis is more highly predictive of adult
    delta smelt salvage than any of the analysis
    presented by the FWS in the Draft BO. It
    clearly shows that when the monthly OMR
    68                     SAN LUIS V. JEWELL
    flows are more negative than about !5,000
    cfs., the risk of salvage increases dramatically.
    ....
    Given the lack of clear relationship between
    salvage and population effects, any constraints
    on salvage needs to focus on avoiding peak
    entrainment events rather than attempting to
    eliminate salvage. Therefore, we again
    suggest that this analysis be included in the
    BO and that the !5,000 cfs OMR flows on a
    14 day average period be used except in rare
    circumstances where the data indicates that
    less negative flows are needed to protect
    against peak entrainment events.
    (emphasis added).
    Fourth, in its comments on an early draft BiOp, the
    independent peer review also urged consideration of the
    relationship between salvage and OMR flows: “[The
    relationship between OMR flows and salvage] is a sound and
    valuable way to set targets to reduce entrainment. The
    USFWS also presents a reasonable regression analysis to
    determine the break-point in the OMR-salvage relationship
    . . . . The breakpoints determined by these analyses were used
    to justify the selection of target OMR flows.”28 It was not
    arbitrary and capricious for the FWS to rely on DWR’s own
    28
    At the same time, the DWR criticized the draft because “the analysis
    appeared to be well done but was poorly described and largely
    undocumented.”
    SAN LUIS V. JEWELL                     69
    expertise and views on the appropriate flow limits, even if it
    did not accept DWR’s preferred recommendation.
    Finally, we have one last observation in this area. When
    the district court remanded the 2005 BiOp as arbitrary and
    capricious—a BiOp that concluded that the operations of
    CVP and SWP would not adversely affect the delta
    smelt—the district court ordered Reclamation and DWR to
    “operate the CVP and SWP to achieve a daily average net
    upstream (reverse) flow in the OMR not to exceed [!]5,000
    cfs on a seven-day running average.” San Luis & Delta-
    Mendota, 
    760 F. Supp. 2d at
    863–64. During the drafting of
    the BiOp, an interagency delta smelt team (known as the
    “Delta Smelt OCAP BO Technical Team”) “discussed the
    merits of using !5,000 OMR per Wanger Order rather than
    !3,500 OMR as recommended in the proposed draft action.”
    Notes of the meeting state:
    The !5,000 OMR cap was established by
    Wanger. The Team discussed the biological
    needs of the smelt to remove jeopardy and
    adverse modification. What might have
    worked in the year 2002 might not work
    correctly in 2009 because the population has
    crashed. It was suggested that scaling the
    amount of protection to the fall mid-water
    trawl (FMWT) (i.e. an estimate of abundance)
    would be helpful.
    ....
    If !5,000 OMR is the cap to protect adults,
    then the cap for Action #3 should be less than
    that, because the juvenile behave more like
    70                   SAN LUIS V. JEWELL
    particles. . . . OMR rates directly relate to
    zone of entrainment. If fish are really out of
    the central Delta then perhaps !5,000 OMR
    might provide sufficient protection. However,
    it is extremely difficult to determine when fish
    are out of South/Central Delta.
    The district court criticized the FWS for relying on “a
    provisional court order, entered as a remedial stopgap
    measure pending comprehensive scientific analysis.” San
    Luis & Delta-Mendota, 
    760 F. Supp. 2d at 896
    . We
    understand the district court’s concern and agree with the
    court’s general proposition that evidence used to support a
    “stopgap measure” is not, without more, substantial evidence
    supporting a final measure. But we also think the principle is
    not so easily applied in this case. As the district court noted,
    its 2007 order—in which the !5,000 cfs figure was
    found—was based on an evidentiary hearing in which two
    studies were introduced that considered the relationship
    between OMR flows and delta smelt salvage. 
    Id.
     According
    to the district court, one of these studies was the basis for B-
    13.
    The FWS can hardly be faulted for thinking that the
    district court’s acceptance of those studies and the issuing of
    an order with real-world consequences for people and smelt
    might present at least a prima facie case for the !5,000 cfs
    figure. We understand and agree with the district court that
    if the district court’s interim order was the sole basis for the
    FWS’s BiOp that it would not constitute substantial evidence.
    But, in 2008, the FWS was at least entitled to rely on the
    studies the district court had accepted (albeit on an interim
    basis) in 2007. The interagency team’s infelicitous reference
    to the “Wanger Order” was surely a shorthand for the
    SAN LUIS V. JEWELL                            71
    evidence on which the district court based its interim order,
    and not just the order itself. Additionally, we can take notice
    of the fact that by 2008, when the BiOp was issued, the FWS
    had a year’s experience living under the district court’s order,
    as the members of the interagency delta smelt team
    undoubtedly knew. Again, if the “Wanger Order” was the
    sole evidence in the record for the FWS’s RPA Component
    2 (Action 3), we would not hesitate to find that the agency
    had not relied on the “best scientific data available,” but
    where the !5,000 cfs figure in the Wanger Order was one
    more data point for the agency, we cannot find that the
    agency’s reference is irrelevant or improper.
    3. The OMR flow limits exist as one part in a dynamic
    monitoring system that accounts for the smelt
    population as a whole29
    As we have described, the FWS’s task of monitoring
    OMR flow and smelt population is a daunting one. The BiOp
    accounts for these challenges in a number of ways, including
    choosing conservative models so as to best meet its ESA
    obligations. One other way in which the BiOp addresses
    these practical difficulties is by integrating its various
    protections; the OMR flow limits exist as but one part of a
    complicated dynamic system. Another significant part of this
    system is a limit on the total allowable take of delta smelt: the
    incidental take limit (ITS). BiOp at 387.
    29
    We do not believe the BiOp’s OMR flow limits to be arbitrary and
    capricious for several alternative reasons previously described. But, even
    had the FWS relied entirely on Figures B-13 and B-14 in setting the OMR
    flow limits—it did not—and even if such total reliance would otherwise
    be arbitrary and capricious—it would not—we hold that the BiOp’s use
    of whole population numbers in the ITS fully supports its OMR flow
    limits.
    72                  SAN LUIS V. JEWELL
    The ITS influences OMR flow levels in two primary
    ways. First, the ITS is used to establish a “Concern Level”
    estimate to “help guide implementation of the RPA.” 
    Id.
     By
    “indicat[ing when] salvage levels approach[] the take
    threshold,” the Concern Level acts “as an indicator that
    operations need to be more constrained to avoid exceeding
    the incidental take.” 
    Id.
     If the Concern Level is actually
    reached, a meeting of the Smelt Working Group—a group
    comprised of interagency biologists who monitor delta smelt
    conditions and recommend OMR flow levels—is triggered.
    
    Id.
     Second, the ITS “functions as an action that influences
    operations under the RPA.” San Luis & Delta-Mendota,
    
    760 F. Supp. 2d at 929
    . Pertinent to the present discussion,
    the ITS is used to set actual flow levels under the RPA in real
    time. BiOp at 352, 354, 357. The real-time actual flow levels
    are set and adjusted based on the input of the Smelt Working
    Group and Project operators—a group informed by the ITS.
    BiOp at 352, 354, 357.
    Thus, the actual OMR flow is highly influenced by the
    ITS, as these two provisions work together as part of the
    complex dynamic system established by the BiOp. This is
    relevant to the present discussion: even while the OMR flow
    limits, viewed in isolation, may not account for total smelt
    population in a manner acceptable to the district court, the
    ITS—and therefore the actual OMR flows—takes the total
    smelt population into account.
    The ITS establishes take limits that vary each year based
    on the preceding Fall Midwater Trawl index (FMWT), an
    abundance proxy for the delta smelt’s population size—and
    the proxy for population suggested both by the FWS and the
    court-appointed experts as they considered normalizing the
    data in B-13. BiOp at 287, 383–86. The ITS is calculated by
    SAN LUIS V. JEWELL                      73
    projecting future salvage from historic salvage in years with
    comparable flows to the RPA, BiOp at 384, and then scaling
    that number to overall abundance using the prior year’s
    FMWT, BiOp at 385. This procedure “yields a discrete value
    for take as salvage so that the adaptive process can operate
    relative to an estimate of the absolute number of fish extant
    in the system.” San Luis & Delta-Mendota, 
    760 F. Supp. 2d at
    926–27. As such, the take limits are adjusted to reflect the
    best estimate of smelt’s existing population. BiOp at 354
    (noting both salvage and population size as “important
    variables” in setting flow). Thus, in making real-time
    operational recommendations to implement the RPA, the
    BiOp relies on both raw salvage numbers and the whole smelt
    population. BiOp at 352.
    In conclusion, we agree that the FWS should have at least
    prepared a graph similar to B-13 based on normalized data or
    explained why it could not. Nevertheless, overall, its use of
    OMR flows is supported by substantial evidence in the
    record. As convoluted as the BiOp is, we can discern the path
    the agency took to arrive at the !5,000 cfs figure used in RPA
    Component 1 (Actions 1 and 2) and RPA Component 2
    (Action 3). See Bowman Transp., Inc. v. Arkansas-Best
    Freight Sys., Inc., 
    419 U.S. 281
    , 286 (1974) (“[W]e will
    uphold a decision of less than ideal clarity if the agency’s
    path may reasonably be discerned.”). In the sense explained
    by Dr. Quinn, the BiOp’s choice of !5,000 cfs was arbitrary;
    that is, the FWS had to choose some number from a broad
    range—perhaps in the !4,000 cfs to !6,000 cfs range—and
    no graphs or charts were likely to give the FWS a precise
    number. In this sense, !5,000 cfs is arbitrary because no
    more precise number can be identified, and a number from
    the range must be selected; !5,000 is thus an arbitrary
    number because the FWS could also have chosen !4,999 or
    74                  SAN LUIS V. JEWELL
    !5,001 or some other number within the range. That !5,000
    is arbitrary in this sense does not make the choice of !5,000
    arbitrary in the sense captured by the APA; its decision was
    not the result of arbitrariness or caprice. The APA does not
    demand strict scrutiny. The FWS is charged with protecting
    the delta smelt, and it chose a reasonable figure.
    B. The 2008 BiOp’s Determination of X2 Was Not Arbitrary
    and Capricious
    The FWS found that Reclamation and DWR’s proposed
    operations “are likely to negatively affect the abundance of
    delta smelt” by “substantially decreas[ing] the amount of
    suitable abiotic habitat for delta smelt.” BiOp at 236–37. To
    address the loss of habitat, the FWS proposed in RPA
    Component 3 (Action 4) that in September and October, in
    years when the preceding precipitation and runoff period was
    defined as “wet or above normal,” Reclamation and the DWR
    must provide sufficient Delta outflow to maintain monthly
    average X2 no more eastward than 74 km from the Golden
    Gate in wet years and 81 km in “above normal” immediate
    water years. BiOp at 282, 369. The FWS had previously
    found that the amount and quality of spawning habitat
    available to delta smelt is linked to the location of X2. BiOp
    at 239–40. As we previously discussed, X2 represents the
    point in the Bay-Delta estuary where the salinity is two parts
    per thousand, and is the center point of the LSZ, which is
    considered suitable spawning habitat for the smelt. X2, in
    turn, depends on delta outflow, which is largely determined
    by the difference between the total inflow from the
    Sacramento and San Joaquin Rivers and the total amount of
    water exported through the Banks and Jones pumping
    SAN LUIS V. JEWELL                             75
    stations, which changes both annually and seasonally.30 BiOp
    at 236. As the BiOp found, “CVP/SWP operations control
    the position of X2 and therefore are a primary driver of delta
    smelt habitat suitability.” BiOp at 234. Because the location
    of X2 directly affects how much water can be exported to
    southern California for agricultural and domestic purposes,
    the determination of where X2 is located was critical to the
    parties.
    The district court found the BiOp was arbitrary and
    capricious with respect to the location of X2 on two grounds.
    First, the district court objected to the data the FWS used to
    locate X2. San Luis & Delta-Mendota, 
    760 F. Supp. 2d at
    903–09. Second, it found that the actual location of X2
    lacked support in the record. 
    Id.
     at 910–13, 922–23. We will
    address each point in turn.
    1. The FWS was not arbitrary and capricious in
    comparing DAYFLOW to CALSIM II
    The FWS used two sophisticated models to determine the
    impacts of past, present, and future operations of the Project
    on X2. The FWS chose a computer model called
    DAYFLOW, developed by DWR, to measure the historical
    environmental baseline, and a computer simulation model
    known as CALSIM II, developed jointly by DWR and
    Reclamation, to measure future operations. 
    Id.
     at 896–98,
    907. These models were used in a number of ways in the
    BiOp, and were important to the BiOp’s determination of the
    30
    It is more correct to think of X2 as a range of points rather than a
    single, fixed point in the estuary. As the BiOp points out, “X2 is strongly
    influenced by tidal cycles, moving twice daily up and downstream 6–10
    km for its average daily location.” BiOp at 372.
    76                  SAN LUIS V. JEWELL
    impacts of Project operation on the location of X2. BiOp at
    145.31
    The DAYFLOW computer model uses past river flow,
    export pumping, precipitation, and estimated agricultural
    diversions from 1967–2007 to estimate the outflow from the
    Bay-Delta to the San Francisco Bay. This data was used by
    the BiOp as a “historic” baseline for X2. BiOp at 207.
    CALSIM II is a computer simulation model that uses Central
    Valley hydrology from 1922–2003 to simulate Project
    operations. Despite the fact that environmental regulation
    and non-Project water demands have historically changed, the
    CALSIM II model assumes that these factors are fixed in its
    modeling scenarios. BiOp at 207. This is in contrast with the
    DAYFLOW model, which, because it relies largely on actual
    reported data, does account for changes in regulations that
    impact water demand. DAYFLOW and CALSIM II also
    differ in other ways: for example, DAYFLOW uses historical
    data to provide daily simulations of operation whereas
    CALSIM II models Project operations on a monthly basis,
    and DAYFLOW calculates X2 location using a mathematical
    method known as the “KM” method whereas CALSIM II
    uses the “ANN” mathematical method.
    The BiOp, in analyzing the predicted location of X2,
    estimated that median X2 would move 10 to 15 percent
    farther upstream under the proposed action relative to the
    historic median X2 baseline. BiOp at 265; see also BiOp at
    235. Appellees assert, however, that it is impossible to
    discern whether “this change was due to continued project
    operations into the future or whether the change was due to
    31
    Action 4, which involves the management of X2, was also
    significantly influenced by these models.
    SAN LUIS V. JEWELL                              77
    the modeling differences between the ‘historic’ Dayflow-
    derived baseline and the Calsim II studies.” Appellees argue
    that a CALSIM II to CALSIM II comparison would have
    been preferable. The district court agreed, concluding that
    although the FWS had discretion to use a historical baseline
    model such as DAYFLOW, the FWS abused its discretion
    when it compared the two different models without
    discussing or accounting for the resulting bias. See San Luis
    & Delta-Mendota, 
    760 F. Supp. 2d at
    902–05. Although the
    district court acknowledged that “no superior set of models
    have been identified,” it held that a calibration problem
    created by using DAYFLOW with CALSIM II made the
    FWS’s choice of methodology arbitrary and capricious and
    required correction or explanation. 
    Id. at 877, 899, 909
    . We
    recognize that the CALSIM II to DAYFLOW comparison is
    not without its limitations, but hold that the FWS’s decision
    to use these two models together, even without further
    calibration, was not arbitrary and capricious.32
    Because the FWS’s decision to use the DAYFLOW and
    CALSIM II models together is a “scientific determination,”
    Baltimore Gas & Elec. Co., 
    462 U.S. at 103
    , that “requires a
    32
    It is not clear from the record that the district court was correct in
    concluding that the FWS’s reliance on a comparison of CALSIM II and
    DAYFLOW models taints the BiOp’s conclusions regarding the impacts
    of Project operations on the location of X2, or regarding Action 4. See
    San Luis & Delta-Mendota, 
    760 F. Supp. 2d at
    922–23. The FWS has
    indicated other possible bases for its conclusions. For example, the FWS
    refers to field sampling data, and not modeling results, as providing the
    basis for its conclusions about X2 conditions, at least in the fall. The BiOp
    also relies on historical data to demonstrate the upstream shift of fall X2
    over time, BiOp at 237, 264, as well as the extent to which the Project
    operations influenced the upstream shift in fall X2, BiOp at 179–82, 236,
    270. See also Note 33 infra.
    78                    SAN LUIS V. JEWELL
    high level of technical expertise,” Marsh, 
    490 U.S. at 377
    , we
    must be at our most deferential in reviewing this provision of
    the BiOp, Baltimore Gas & Elec. Co., 
    462 U.S. at 103
    .
    Therefore, the question, under the ESA is not whether the
    FWS should have conducted independent studies in lieu of
    DAYFLOW or CALSIM II, Sw. Ctr. for Biological Diversity,
    
    215 F.3d at 60
     (“[T]he Secretary has no obligation to conduct
    independent studies.”), but whether these models represent
    the “best scientific and commercial data [currently]
    available,” 
    16 U.S.C. § 1536
    (a)(2); Inland Empire Public
    Lands Council v. U.S. Forest Serv., 
    88 F.3d 754
    , 762 (9th Cir.
    1996). Because we agree with the district court’s conclusion
    that “no superior set of models have been identified,” San
    Luis & Delta-Mendota, 
    760 F. Supp. 2d at 909
    , the only
    question is whether the FWS’s failure to calibrate the two
    models renders conclusions drawn from their evidence not
    merely “weak,” but “arbitrary and capricious.” Greenpeace
    Action v. Franklin, 
    14 F.3d 1324
    , 1336 (9th Cir. 1992)
    (noting that “the fact that the evidence [that an agency relies
    on] is ‘weak’” is not dispositive); see also Bldg. Indus. Ass’n
    of Superior Cal. v. Norton, 
    247 F.3d 1241
    , 1246–47 (D.C.
    Cir. 2001) (holding that the fact that the “studies the Service
    relied on were imperfect . . . alone is insufficient to
    undermine those authorities’ status as the ‘best scientific . . .
    data available’”).
    The FWS explained why it chose to use “a combination
    of available tools and data.”33 San Luis & Delta-Mendota,
    33
    The BiOp makes clear that the FWS did not rely exclusively on the
    CALSIM II/DAYFLOW comparison, but looked to previous government
    studies, and several peer-reviewed scientific studies:
    SAN LUIS V. JEWELL                            79
    
    760 F. Supp. 2d at 912
    ; BiOp at 204–05. The BiOp explained
    that it used the DAYFLOW model as a baseline, rather than
    a different CALSIM II simulation, because when it compared
    a CALSIM II simulation of current Project operations to a
    CALSIM II simulation of past Project operations, it found
    that the two were “nearly identical,” despite the fact that past
    and current Project operations are significantly different.
    BiOp at 204–05. According to the BiOp, “changes were
    expected” between the two CALSIM II studies. BiOp at 204.
    Because that comparison did not yield significant differences,
    as the FWS anticipated, the BiOp concluded that “the
    CALSIM monthly simulation model does not capture a
    precise Delta operation.” BiOp at 204. These “inaccuracies
    in CALSIM [lead the FWS] to use actual data to develop an
    empirical baseline.” BiOp at 206. The FWS chose “the
    DAYFLOW database . . . and OMR data obtained from
    USGS.” BiOp at 206. The BiOp also noted that the
    CALSIM II simulation provided “an imperfect representation
    of the pre-POD [pelagic organism decline]” environmental
    situation and that supplemental analysis was needed “to
    compensate for this modeling limitation.” BiOp at 205. In
    This analysis of the effects of proposed CVP and SWP
    operations on the delta smelt and its critical habitat uses
    a combination of available tools and data, including the
    CALSIM II model outputs provided in the appendices
    of Reclamations’ 2008 biological assessment, historical
    hydrologic data provided in the DAYFLOW database,
    statistical summaries derived from 936 unique 90-day
    particle tracking simulations published by Kimmerer
    and Nobriga (2008), and statistical summaries and
    derivative analyses of hydrodynamic and fishers data
    published by Feyrer et al. (2007), Kimmerer (2008),
    and Grimaldo et al. (accepted manuscript).
    BiOp at 204.
    80                  SAN LUIS V. JEWELL
    other words, when the FWS used CALSIM II as both a
    baseline and as a predictor, it appeared to yield inaccurate
    results, so the FWS used the next best available baseline: the
    DAYFLOW model.            Thus, the FWS explained: the
    “[CALSIM II] Study 7.0 was the model run that Reclamation
    and DWR thought best represented current operations, and
    was thus intended as a ‘current baseline.’ However, due to
    limitations of CALSIM II to accurately model actual
    operations, [the FWS] also used the 1967–2007 DAYFLOW
    summaries . . . to compare against CALSIM II outputs.” BiOp
    at 207.
    The district court acknowledged that “[t]he theoretical
    problems with using a Calsim II to Calsim II comparison
    were manifest,” yet it found that the “FWS’s decision to use
    a Calsim II to Dayflow comparison . . . without attempting to
    calibrate the two models . . . was arbitrary and capricious and
    ignored the best available science showing that a bias was
    present.” San Luis & Delta-Mendota, 
    760 F. Supp. 2d at
    906–07. The evidence for the modeling bias in the CALSIM
    II/DAYFLOW comparison was not clearly identified in the
    comments sent to the FWS before it issued the BiOp, and the
    comments largely recommended correcting the bias by
    comparing one CALSIM II model to another CALSIM II
    model—precisely the comparison the FWS found flawed and
    inaccurate. For example, San Luis & Delta-Mendota Water
    Authority, one of the plaintiffs-appellees here, submitted
    extensive and thoughtful comments on a portion of the draft
    BiOp and peer review analysis. The water authority
    expressed its concern that it was “methodologically
    inappropriate to compare historical data to simulated data.
    Simulated data must be compared to simulated data.” The
    DWR advised the FWS of some of the same problems. In its
    comments on a portion of the draft BiOp, the DWR pointed
    SAN LUIS V. JEWELL                          81
    out that the model made assumptions that might not be borne
    out in the historical data and that “[g]reat caution should be
    taken when comparing actual data to modeled data.” Like the
    water authority, it too recommended that CALSIM II
    modeling “be used to compare one set of model runs to
    another.” In later comments, the DWR repeated its concern
    that the BiOp “compared model runs of future operation with
    historical conditions” and suggested that “[i]mpact analyses
    often compare only model scenarios to avoid these . . .
    problems.” The independent peer review panel also
    expressed some concern with comparing the historical
    baseline with the CALSIM II simulated results. It pointed out
    that the “large difference between [CALSIM II] results and
    the historical baseline conditions defined with data can
    confuse the comparisons of metrics . . . between a simulated
    study and historical baseline.” The panel suggested that
    “[i]deally, a model-simulated baseline should be available
    that is consistent with the historical data . . . . It is unfortunate
    that model-generated baselines with a high degree of
    reliability were not made available for this analysis.”
    The post-hoc views of the court’s experts reflect some
    similar concerns. Dr. Quinn agreed that a comparison
    between models with identical databases and assumptions
    was preferable, but advised that “[a]s long as we bear in mind
    the fact that these are two very different models, I do not see
    why we cannot compare them.” After discussing some of the
    data provided to him, he concluded that
    the outputs from the two models cannot be
    used interchangeably for estimating either X2
    (in km) or flow (in cfs). This does not reflect
    any criticism of either model. Their inner
    workings are apparently quite different, as are
    82                   SAN LUIS V. JEWELL
    their fundamental purposes, as explained to
    us. However any comparisons between them
    must explicitly account for the differences.
    Similarly, Dr. Punt stated that
    [i]n principle, there is nothing wrong with
    fitting a model using a set of OMR/X2 values
    from one model and making predictions using
    OMR/X2 values which are based on the
    output from a different model, as long as the
    two sets of values are calibrated . . . .
    Dr. Punt noted that the FWS had articulated its assumptions
    and explained why he thought the FWS should have
    performed additional calibration:
    It is recognized in the record that the modeled
    X2 does not reflect the “historical” X2 (BiOp
    Figure E-28), and the BiOp does compare
    historical and CALSIM-predicted X2 values
    by month (Figure E-26). However, the BiOp
    does not make this comparison for
    comparable years.         Failure to attempt
    examination of whether it is necessary to
    calibrate the historical data and the CALSIM
    output would not normally be considered
    appropriate scientific practice in the field.
    (internal citations omitted).
    We recognize that the FWS’s decision to compare its
    chosen baseline, produced by DAYFLOW, to its future
    projection, produced by CALSIM II, was not perfect—as
    SAN LUIS V. JEWELL                             83
    everyone has acknowledged. We nevertheless hold that this
    comparison was not arbitrary and capricious. The BiOp
    explained its assumptions and explained why it rejected the
    CALSIM-to-CALSIM comparison suggested by the DWR
    and others who reviewed the draft BiOp. The fact that the
    FWS chose one flawed model over another flawed model is
    the kind of judgment to which we must defer. As we said in
    Environmental Defense Center, Inc. v. EPA: “We defer to an
    agency decision not to invest the resources necessary to
    conduct the perfect study, and we defer to a decision to use
    available data unless there is no rational relationship between
    the means [the FWS] use[d] to account for any imperfections
    in its data and the situation to which those means are
    applied.” 
    344 F.3d 832
    , 872 (9th Cir. 2003) (citations
    omitted). “The existence of a flaw . . . does not require us to
    hold that the agency’s use of the model was arbitrary.” Am.
    Iron & Steel Inst. v. EPA, 
    115 F.3d 979
    , 1005 (D.C. Cir.
    1997) (per curiam). Rather, we will “reject an agency’s
    choice of a scientific model ‘only when the model bears no
    rational relationship to the characteristics of the data to which
    it is applied.’” Nat’l Wildlife Fed’n v. EPA, 
    286 F.3d 554
    , 565
    (D.C. Cir. 2002) (quoting Appalachian Power Co. v. EPA,
    
    135 F.3d 791
    , 802 (D.C. Cir. 1998)); accord Envtl. Def. Ctr.,
    
    344 F.3d at 872
    . That is not the case here. The district
    court’s determination to the contrary was heavily influenced
    by experts supplied by the parties which, for the reasons that
    we have explained, was inappropriate. The record is less
    certain than the district court was willing to admit.34 That
    34
    The district court refers to testimony from the parties’ experts in terms
    that overstate what the record will bear. See, e.g., San Luis & Delta-
    Mendota, 
    760 F. Supp. 2d at 909
     (“undisputed expert testimony”), 
    id.
    (“[A]ll experts in this case agree”), 
    id. at 912
     (“[u]ndisputed expert
    84                    SAN LUIS V. JEWELL
    appellees were able to produce post-hoc theories alluding to
    the possibility of bias from such a comparison does not
    invalidate the FWS’s choices where there is no indication that
    a failure to calibrate would do more than add an uncertainty
    factor to the results, as well as no indication that a de-biasing
    calibration is technically feasible. Under our deferential
    standard of review, we therefore hold that the FWS’s choice
    and use of models was based on the best available science.
    Ideally, the FWS would have thoroughly discussed its
    reasoning with regard to possible issues arising from the use
    of DAYFLOW with CALSIM II. But, the fact that the
    FWS’s explanation for its choices does not fully address
    every possible issue that flows from that choice does not
    render the FWS’s determination unreasonable or
    unsupported. We do not require agencies to analyze every
    potential consequence of every choice they make; to do so
    would put an impossible burden on agencies. Rather, “we
    review all agency choices with respect to models,
    methodologies, and weighing scientific evidence” to ensure
    that the agency’s “choices [are] supported by reasoned
    analysis.” Ecology Ctr. v. Castaneda, 
    574 F.3d 652
    , 665 (9th
    Cir. 2009). Particularly in an area as “unwieldy and science-
    driven” as this, the FWS’s statistical modeling “does not
    easily lend itself to judicial review.” Appalachian Power,
    
    135 F.3d at 802
    ; see 
    id.
     (“Statistical analysis is perhaps the
    prime example of those areas of technical wilderness into
    which judicial expeditions are best limited to ascertaining the
    lay of the land.”). “[T]hat some or many [experts] would
    disapprove [of the FWS’s] approach does not answer the
    question presented to us. In reviewing [the FWS’s BiOp], we
    testimony”), 
    id. at 922
     (“the Calsim II to Dayflow comparison has the
    potential to introduce significant, if not overwhelming, bias”).
    SAN LUIS V. JEWELL                       85
    do not sit as a panel of referees on a professional [scientific]
    journal, but as a panel of generalist judges obliged to defer to
    a reasonable judgment by an agency acting pursuant to
    congressionally delegated authority.” City of L.A. v. Dep’t of
    Transp., 
    165 F.3d 972
    , 977 (D.C. Cir. 1999). In this instance,
    the FWS has provided a reasoned analysis explaining why the
    DAYFLOW model was used as the baseline.
    Consequently, we hold that the FWS did not act
    arbitrarily and capriciously in relying on the CALSIM II and
    DAYFLOW models in evaluating the impacts of Project
    operations on the location of X2, or in justifying Action 4.
    2. The BiOp sufficiently explained the fall X2 locations
    The district court held that the BiOp “fails to explain why
    it is essential to maintain X2 at 74 km and 81 km,
    respectively, as opposed to any other specific location.” San
    Luis & Delta-Mendota, 
    760 F. Supp. 2d at 923
    . Specifically,
    the court found the “Federal Defendants have not identified
    any record evidence that provides such an explanation. This
    total lack of explanation violates the APA[].” 
    Id. at 922
    .
    With respect to the latter finding, the record is contrary to the
    district court’s finding. There is record support for the
    BiOp’s proposal. Whether the record will “explain why it is
    essential to maintain X2 at 74 km and 81 km . . . as opposed
    to any other specific location” is a different question. In fact,
    it is the wrong question.
    As we have previously explained, as the combined
    pumping operations of the SWP/CVP remove hundreds of
    thousands of gallons of fresh water from the Bay-Delta,
    X2—the salinity-defined location of the smelt’s primary
    spawning habitat—shifts eastward towards the delta. BiOp at
    86                  SAN LUIS V. JEWELL
    373. As the ocean’s salty influence encroaches further
    upstream, it mimics drought conditions in the Bay-Delta,
    regardless of the previous season’s precipitation. BiOp at
    271, 273–74 (plotting spring and fall X2 locations). Among
    other things, this has resulted in an increasing divergence
    between spring and fall X2 locations. The BiOp determined
    that the “long-term upstream shift in X2 during fall has
    caused a long-term decrease in habitat area availability for
    delta smelt,” and it set forth an adaptive management
    program to minimize the effects of Project pumping on X2:
    RPA Action 4. BiOp at 374. Action 4 targets the fall
    location of X2 during “wet” and “above normal” years: “the
    years in which project operations have most significantly
    adversely affected fall [X2 location].” BiOp at 373.
    Specifically, Action 4 requires that fall X2 be maintained at
    a location no greater than 74 km upstream from the Golden
    Gate Bridge following “wet” water years, and no greater than
    81 km upstream following “above normal” water years.
    BiOp at 282–83.
    The BiOp includes a number of different explanations,
    both specific and general, for RPA Component 3 (Action 4)’s
    regulation of X2 location. First, as discussed in the previous
    section, the FWS used CALSIM II and DAYFLOW to give
    it a picture of where X2 was located. Those models predicted
    different values for the location of X2 based on differing
    assumptions. DAYFLOW relied on historical data, while
    CALSIM II predicted where X2 might be located based on
    future Project operations. The FWS found that the two
    models offered different estimates of X2 location, and that, in
    general, “CALSIM II modeled scenarios were 10–15 percent
    further upstream than actual historic X2.” BiOp at 235.
    Thus, “[m]edian historic fall X2 was 79 km, while median
    values for the CALSIM II modeled scenarios ranged from 87
    SAN LUIS V. JEWELL                      87
    to 91 km. The CALSIM II modeled scenarios all had an
    upper range of X2 at about 90 km.” BiOp at 235. The FWS
    generated numerous figures and charts with information taken
    from these models, many of which graphed X2 location as a
    function of another variable. See, e.g., BiOp at 260–61, 265,
    270, 281, 282, 283, 284, 285. The FWS’s graphing range for
    X2 location was 60–95 km, with most data points between
    65–85 km, and a significant cluster between 70–85 km. BiOp
    at 270.
    Second, the data from the models was consistent with the
    FWS’s written finding that “[d]uring the past 40 years,
    monthly average X2 has varied from as far downstream as
    San Pablo Bay (45 km) to as far upstream as Rio Vista on the
    Sacramento River (95 km). . . . In general, delta smelt habitat
    quality and surface area are greater when X2 is located in
    Suisun Bay.” BiOp at 191. Elsewhere in the BiOp, the FWS
    found based on an outside scientific study that “prior to
    spawning entrainment vulnerability of adult delta smelt
    increased at the SWP and CVP when X2 was upstream of
    80km.” BiOp at 219.
    Third, the BiOp pointed out that X2 varies in response to
    a number of factors, both natural and man-made. The natural
    factors include the tides and the spring inflow. The BiOp
    found that “X2 is strongly influenced by tidal cycles, moving
    twice daily up and downstream 6–10 km from its average
    daily location.” BiOp at 372. The spring runoff affects X2 as
    well. The BiOp found that “very high spring outflows have
    always pushed X2 far downstream resulting in delta smelt
    distributions distant from the influence of Banks and Jones.”
    BiOp at 221. Aside from CVP/SWP’s operations, there are
    other man-made factors to consider. For example, the Suisun
    Marsh Salinity Control Gates have historically been
    88                   SAN LUIS V. JEWELL
    operational for anywhere from 10 to 120 days a year. BiOp at
    218. Operation of the salinity control gates may shift X2 as
    far as 3 km upstream. BiOp at 218; see also BiOp at 241,
    243–44. The BiOp noted that the 3 km upstream shift was
    preferable to the “10–20 km shifts that have occurred for up
    to 120 or more days per year during late summer through
    early winter due to South Delta diversions.” BiOp at 219.
    Fourth, the BiOp also points out that not all habitats in the
    Bay-Delta are equally suited to the smelt, so that as X2
    location shifts, the smelt may be affected by other factors as
    well. For example, as X2 location shifts, the delta smelt
    encounter changes in agricultural runoff; changes in turbidity,
    which affects smelt feeding and predation; and exposure to
    predators. E.g., BiOp at 372 (“the daily fluctuation in X2
    around an upstream point such as Brown’s Island confines the
    [smelt] population to narrow channels, where delta smelt may
    be exposed to more stressors (e.g., agricultural diversions,
    predation) relative to a downstream X2”); BiOp at 238
    (“[T]he eastward movement of X2 will shift the distribution
    of delta smelt upstream, and provide environmental
    conditions for nonnative fishes that thrive in stable
    conditions.” (internal citation omitted)). Thus, the BiOp
    points out that although CVP/SWP operations remain the
    most important factor affecting smelt habitat, BiOp at
    177–79, “there is no single driver of delta smelt population
    dynamics,” BiOp at 238; see also BiOp at 202 (referring to
    “the multitude of factors that affect delta smelt population
    dynamics”). The smelt habitat is a complex and dynamic
    system.
    Fifth, because X2 varies not only with CVP/SWP’s
    operations, but with natural phenomena beyond the control of
    the agencies—such as the tides, the seasons, and the annual
    SAN LUIS V. JEWELL                            89
    rainfall—the FWS had a range of choices for X2. Its goal
    was to “move the habitat away from Delta impacts and into
    broader open waters west of Sherman Island.”35 BiOp at 373.
    Rather than trying to define a single point for X2, the FWS
    chose a range, and refined the range by whether the year was
    “wet” or “above normal.” We think there was ample evidence
    in the record to support the choice of X2 between 74 and 81
    km, depending on the season. The district court’s finding that
    there was a “total lack of explanation” is belied by the
    record.36
    It appears the district court focused on whether there was
    support in the record for the FWS’s choice of 74 km, as
    opposed to 73 km or 75 km, hence its decision to question
    whether the FWS had adequately explained “why it is
    essential to maintain X2 at 74km and 81km . . . as opposed to
    any other specific location.” San Luis & Delta-Mendota,
    
    760 F. Supp. 2d at 923
    . This was not the district court’s
    responsibility. The ESA provides that Reclamation had to
    seek the FWS’s opinion to ensure that its operations were
    “not likely to jeopardize the continued existence of any
    endangered species or threatened species or result in the
    35
    Sherman Island lies at the confluence of the Sacramento and San
    Joaquin Rivers. The 74–81 km range selected by the FWS lies west of
    Sherman Island.
    36
    The district court’s conclusion is especially puzzling because it
    accepted a similar FWS finding in its prior decision. See Kempthorne,
    
    506 F. Supp. 2d at 335, 380
     (noting that a survey of delta smelt abundance
    “increases dramatically whenever X2 is located between Chipps and Roe
    islands,” and that “[w]hen X2 is located upstream of Chipps Island, smelt
    are vulnerable to entrainment and are located in an area that is not ideal
    for feeding or protection”) (citing the administrative record). See also
    BiOp at 114, 132.
    90                   SAN LUIS V. JEWELL
    destruction or adverse modification of habitat of such
    species.” 
    16 U.S.C. § 1536
    (a)(2). It is the FWS’s
    responsibility to set forth its opinion and “those reasonable
    and prudent alternatives which [the Secretary of the Interior]
    believes would not violate [§ 1536(a)(2)] and can be taken by
    [Reclamation].” Id. § 1536(b)(3)(A). A “reasonable and
    prudent alternative” is a flexible standard for the consulting
    agency; it is not the equivalent of the “least restrictive
    alternative,” which is the way the district court treated the
    inquiry. Sw. Ctr. for Biological Diversity, 143 F.3d at 523.
    Under the ESA, the consulting agency is “not required to
    explain why he chose one RPA over another,” nor is it
    “required to pick the best alternative or the one that would
    most effectively protect the [species] from jeopardy.” Id.
    Rather, the FWS “need only have adopted a final RPA which
    complied with the jeopardy standard and which could be
    implemented by the agency.” Id. Accordingly, it was error
    for the district court to hold that the FWS must “explain why
    it is essential to maintain X2 at 74 km and 81 km . . . as
    opposed to any other specific location.” San Luis & Delta-
    Mendota, 
    760 F. Supp. 2d at 923
    .
    Even if we thought the ESA demanded the kind of
    precision insisted on by the district court, we believe there is
    an explanation in the record for the FWS’s choice of 74 km
    and 81 km as its seasonal parameters. And the explanation is
    both logical and simple: At 74 km there is a monitoring
    station for the Bay-Delta at Chipps Island; at 81 km there is
    a monitoring station at Collinsville. BiOp at 114, 132. In its
    comments to the FWS, the DWR questioned the feasibility of
    locating fall X2, “especially if the spring X2 location is
    SAN LUIS V. JEWELL                            91
    significantly west of Port Chicago.”37 The DWR was
    concerned with how the agencies would measure compliance
    with any standard selected by the FWS and pointed out that
    “it would be difficult to measure an X2 at 85 km, whereas it
    would be much easier to measure at Collinsville (81 km) or
    Emmaton (92 km).” Where X2 represents a range of choices,
    choosing an X2 that can be measured and enforced is a
    perfectly rational response. See Sw. Ctr. for Biological
    Diversity, 143 F.3d at 523.
    We recognize that the stakes are exceedingly high in this
    case, but we conclude that the FWS’s choice, given the
    record, represented a reasonable and prudent alternative.
    C. The BiOp’s Incidental Take Statement Is Not Flawed
    When the implementation of an RPA will cause
    “incidental take” of a species, defined as “takings that result
    from, but are not the purpose of, carrying out an otherwise
    lawful activity conducted by the Federal agency or
    applicant,” 
    50 C.F.R. § 402.02
    , the agency is required to
    provide an incidental take statement (ITS) that “[s]pecifies
    the impact, i.e., the amount or extent, of such incidental
    taking on the species,” 
    50 C.F.R. § 402.14
    (i)(1)(i); see
    
    16 U.S.C. § 1536
    (b)(4)(C)(i). The FWS determined that
    “take of the delta smelt is likely to occur in the form of kill,
    capture (via salvage), wound, harm, and harass as a result of
    CVP/SWP operations within the action area,” BiOp at 286,
    and prepared an ITS, BiOp at 285–310. In the ITS, the FWS
    provided separate take limits for juvenile and adult smelt,
    noting that “individuals of the larval/juvenile lifestage are
    37
    The FWS did not set its fall X2 target at Port Chicago, which is west
    of the 74 km marker proposed by the FWS.
    92                   SAN LUIS V. JEWELL
    less demographically significant than adults.” BiOp at 289.
    The FWS used different data sets in determining these
    separate limits. As the ITS notes, “[t]he mean values from
    2005–2008 were used as an estimate of [juvenile] take under
    the RPA,” BiOp at 289, while “[t]he average[] value for
    [water years] 2006 to 2008" was used to calculate pre-
    spawning adult delta smelt, BiOp at 287. In other words, the
    year 2005 was used in calculating the juvenile, but not the
    adult, take limit. BiOp at 287, 289. The ITS also
    acknowledges its limitations: there are numerous
    uncertainties inherent in the measurement of smelt take, and
    “salvage data (our most definitive measurement endpoint)
    reflects only a portion of the total mortality associated with
    entrainment.” BiOp at 383.
    The district court concluded that the BiOp’s ITS was
    arbitrary or capricious for two reasons: First, the district court
    found that the FWS failed to explain adequately its decision
    to use 2005–2008 salvage data when setting the incidental
    take limit for juvenile smelt, but to only use 2006–2008
    salvage data when setting the incidental take limit for adult
    smelt. San Luis & Delta-Mendota, 
    760 F. Supp. 2d at
    925–28.
    Second, the district court found that the FWS failed to explain
    its decision to rely on an average cumulative salvage index
    when it set a “Concern Level,” which, when triggered,
    requires the Smelt Working Group to make “an immediate
    specific recommendation to the [FWS].” BiOp at 387; see
    San Luis & Delta-Mendota, 
    760 F. Supp. 2d at
    928–29. We
    hold that the ITS is not arbitrary and capricious because it
    includes adequate explanation and support for its
    determinations.
    SAN LUIS V. JEWELL                          93
    1. The ITS reasonably uses different data sets for adult
    and juvenile take limits
    First, the district court objected to the FWS’s choice of
    data. The ITS’s use of separate data sets to calculate the
    separate incidental take limits for juvenile and adult smelt is
    adequately explained in the ITS. In discussing the use of
    “[t]he mean values from 2005–2008” to calculate juvenile
    take limits, the ITS explains that “[t]he reason for selecting
    this span of years is that the apparent abundance of delta
    smelt since 2005 as indexed by the 20-mm Survey and the
    [Summer Townet Survey] is the lowest on record.” BiOp at
    289. Accordingly, “[i]t was necessary to separate out this
    abundance variable, but also to account for other poorly
    understood factors relating salvage to OMR, distribution, and
    the extant conditions.” BiOp at 289. As noted elsewhere in
    the BiOp, “[i]n contrast to adult delta smelt, there is no well
    established index of larval and juvenile abundance to reliably
    scale the take of this lifestage to abundance. . . . This should
    be kept in mind . . . .” BiOp at 389. Therefore, faced with a
    greater degree of uncertainty in calculating juvenile incidental
    take, the FWS chose, conservatively, to incorporate an
    additional year of data—a year in which smelt abundance was
    “the lowest on record.”38 BiOp at 389–90. The BiOp is clear
    that it used 2006–2008 data for adults because “these years
    within the historic dataset best approximate expected
    salvage,” BiOp at 287, and 2005–2008 data for juveniles
    because juvenile smelt “are less demographically significant
    than adults,” BiOp at 289, and therefore a larger data set
    38
    This determination came on the heels of the district court’s
    invalidation of the 2005 BiOp’s ITS based on its failure to consider
    record-low population abundance in setting take limits. See San Luis &
    Delta-Mendota, 
    760 F. Supp. 2d at 918
    .
    94                     SAN LUIS V. JEWELL
    would be preferable.39 Such a decision to use a more
    conservative data set, when necessary, is exactly the sort that
    we afford agencies discretion to make. See, e.g., Fishermen’s
    Finest, Inc. v. Locke, 
    593 F.3d 886
    , 893, 896–97 (9th Cir.
    2010) (upholding agency’s decision to rely on some data
    while disregarding other data).
    2. The FWS reasonably uses an average cumulative
    salvage index
    Second, the district court objected to the FWS’s decision
    to use an average cumulative salvage index to create its
    “Concern Level.” BiOp at 387, 389–90. The Concern Level
    “indicate[s] salvage levels approaching the take threshhold.”
    BiOp at 387; see also BiOp at 289 (noting that the estimated
    number represents a concern level where “entrainment has
    reached high enough numbers to indicate the need for more
    protective OMR restrictions.”). When the Concern Level is
    reached, two actions follow: The Smelt Working Group must
    convene and make “an immediate specific recommendation
    to the [FWS],” and OMR flows may have to be adjusted “to
    a more restrictive level.” BiOp at 387. The Concern Level
    does not trigger automatic restrictions in OMR flows. It
    “may require” a reduction “unless available data indicate
    some greater level of exports is possible without increasing
    entrainment.” BiOp at 387 (emphasis added).
    The FWS’s decision to use an average in setting the
    incidental take limits is, like its choice of data sets, a choice
    39
    For similar reasons we disagree with the district court that the FWS
    must explain why it decided to include 2006 when it calculated
    larval/juvenile abundance. See San Luis & Delta-Mendota, 
    760 F. Supp. 2d at
    917–18.
    SAN LUIS V. JEWELL                       95
    entitled to substantial difference. See The Lands Council v.
    McNair, 
    537 F.3d 981
    , 991 (9th Cir. 2008) (noting that it is
    “well-established law” that courts owe deference “to agencies
    and their methodological choices”). As appellees note, the
    ITS’s “use of averaging . . . provides an ‘estimate’ of
    expected take that, based on the historical record of salvage,
    when applied[,] would likely be exceeded in many years.” In
    other words, appellees object to the fact that the ITS’s choice
    of methodology results in too restrictive of a management
    regime. The district court agreed, finding that “[t]he record
    does not explain why an ‘averaging’ approach was used.” San
    Luis & Delta-Mendota, 
    760 F. Supp. 2d at 929
     (“Based on
    known adverse water supply consequences of operating the
    Projects in a ‘constrained’ manner, it is inexplicable that the
    FWS did not provide a clear and rational explanation of how
    the ITS is set.”).
    We hold that the record offers an adequate explanation.
    As with its decision to use an additional year of data when
    calculating the juvenile take limit, the ITS’s use of an
    averaging methodology “counteract[s] the uncertainties”
    inherent in its analyses by “overestimat[ing]” known
    parameters. See Baltimore Gas & Elec. Co., 
    462 U.S. at 103
    .
    In the context of the ITS’s repeated recognition of the
    “difficult[y] [in] definitively project[ing]” the “specific level
    of take of adult delta smelt at the CVP/SWP pumping
    facilities . . . due to inherent uncertainties,” BiOp at 383, the
    FWS’s use of an averaging methodology—that, by its nature,
    yields conservative limits that otherwise would have been
    exceeded in eleven of the past sixteen years, San Luis &
    Delta-Mendota, 
    760 F. Supp. 2d at
    929—is a discernable, and
    justified path. See Bowman Transp., 419 U.S. at 285–86; see
    also Nw. Coal. for Alternatives to Pesticides, 
    544 F.3d at 1050
     (upholding an agency’s discernable reliance on models
    96                   SAN LUIS V. JEWELL
    that “yield conservative data [where] the models
    incorporate[d] the higher of [the potential values] in assessing
    the overall risk”). Moreover, the establishment of a Concern
    Level is an enforcement norm, and thus a policy decision.
    “[S]election of an action level is primarily a legislative policy
    decision that we will uphold so long as it was reasonably
    drawn from the record.” Public Citizen Health Res. Group v.
    Dep’t of Labor, 
    557 F.3d 165
    , 184 (3d Cir. 2009).
    Ultimately, the appellees’ objection is not really to the record
    support for the Concern Level, but to the Concern Level
    itself. The choice of the Concern Level is quintessentially
    one within the discretion of the agency, and we have no basis
    for disturbing it here.
    D. The Record Supports the BiOp’s Conclusions Regarding
    the Indirect Effects of Project Operations
    The FWS is required to take into account both the “direct
    and indirect effects of an action on the species or critical
    habitat” when determining whether an action is likely to
    cause jeopardy. 
    50 C.F.R. § 402.02
    ; see also 
    16 U.S.C. § 1536
    (a)(2). “Indirect effects” are “those that are caused by
    the proposed action and are later in time, but still are
    reasonably certain to occur.” 
    50 C.F.R. § 402.02
    . Here, the
    BiOp identified a number of indirect effects on the delta
    smelt from Project operations. Among other things, it
    concluded that Project operations were reasonably certain to
    (1) limit delta smelt food supply, and (2) increase harmful
    pollution and contaminants. It also noted (3) the harmful
    indirect effects that would likely spring from three “other
    stressors”: predation, aquatic macrophytes, and microcystis.
    See BiOp at 182–88, 202.
    SAN LUIS V. JEWELL                      97
    The BiOp found that a “multitude of factors . . . affect
    delta smelt population dynamics including predation,
    contaminants, introduced species, entrainment, habitat
    suitability, food supply, aquatic macrophytes, and
    microcystis.” BiOp at 202. It concluded that “[t]he extent to
    which these factors adversely affect delta smelt is related to
    hydrodynamic conditions in the Delta, which in turn are
    controlled to a large extent by CVP and SWP operations.”
    BiOp at 202. It noted that there were other sources of water
    diversion that affect smelt through entrainment, but that, even
    when “taken together,” they did not “approach[] the influence
    of the Banks and Jones export facilities.” BiOp at 202.
    Although the BiOp candidly assessed that there was “no
    single primary driver of delta smelt population dynamics”
    and that there were “non-CVP/SWP factors,” it ultimately
    concluded that “the CVP and SWP are a primary driver of
    delta smelt abiotic and biotic habitat suitability, health, and
    mortality” and that CVP/SWP operations “have also played
    an indirect role in the delta smelt’s decline by creating an
    altered environment in the Delta that has fostered the
    establishment of non-indigenous species and exacerbates
    these and other stressors that are adversely impacting delta
    smelt.” BiOp at 202–03.
    The district court was not persuaded, finding that “[t]he
    record does not support the BiOp’s conclusion that food web
    and pollutants/contaminant impacts are indirect effects of
    Project operations.” San Luis & Delta-Mendota, 
    760 F. Supp. 2d at 969
    . The district court also separately noted that “the
    BiOp’s conclusions about the causal connections between
    Project operations and ‘other stressors’ are ambiguous,” and
    thought the effects were “unsupported by record evidence
    and/or explanation” 
    Id.
     We address each of these indirect
    effects in turn, and conclude that the BiOp analysis was
    98                      SAN LUIS V. JEWELL
    sufficiently clear and thorough so as not to be arbitrary and
    capricious, and that it was based on the best available science.
    See Kern, 
    450 F.3d at
    1080–81.
    1. Project operations indirectly affect smelt food supply
    First, the BiOp explores the likely impact of Project
    operations on smelt food supply. The BiOp describes
    “entrainment of Pseudodiaptomus forbesi (P. forbesi), the
    primary prey of delta smelt,” as a primary effect that “will
    adversely affect delta smelt.”40 BiOp at 203–04. Plainly
    stated, delta smelt appear severely food limited much of the
    time. P. forbesi is the smelt’s principal food source from
    summer to early fall, and so any Project impact on the
    availability of P. forbesi represents a threat to the smelt. See
    BiOp 228, 380. The BiOp concludes that such a threat is
    present: high water exports reduce flows that would otherwise
    transport P. forbesi into the delta smelt’s habitat, thereby
    contributing to smelt mortality and population declines. BiOp
    at 184–85, 228. Moreover, as water is pumped from the
    south Bay-Delta during June through September, P. forbesi
    are entrained in pumping stations, thereby reducing the
    overall availability of P. forbesi in the delta. BiOp at 228.
    Because “statistical evidence suggest[s] that the co-
    occurrence of delta smelt and [prey such as P. forbesi] has a
    strong . . . influence on the survival of young delta smelt from
    summer to fall,” BiOp at 228, the BiOp concluded that the
    Project’s effects on the P. forbesi population indirectly
    threaten the viability of delta smelt.
    40
    The FWS proposed to address this through Action 6, which requires
    the creation or restoration of 8,000 acres of habitat in the Delta and in
    Suisun Marsh. BiOp at 381.
    SAN LUIS V. JEWELL                      99
    We consider whether this analysis is supported by the best
    available science, and whether the FWS acted arbitrarily and
    capriciously in concluding, to a “reasonable certainty,” that
    Project operations indirectly affect delta smelt through its
    food supply. See 
    50 C.F.R. § 402.02
    . As both the district
    court and the peer review panel indicated, the FWS’s analysis
    suffers from some methodological limitations; some of the
    analyses underlying the agency’s conclusions involved
    extrapolating from a few sampling sites, and therefore may
    have overstated the scarcity of P. forbesi. The district court
    seized on the peer review panel’s comments, which pointed
    out: “Rather than correct this problem, FWS’s response was
    to abandon the quantitative analysis, choosing to advance the
    same, potentially flawed conclusion in a more subjective,
    qualitative analysis. This conduct suggests another unlawful,
    results-driven choice, ignoring best available science.” San
    Luis & Delta-Mendota, 
    760 F. Supp. 2d at 940
    . We think the
    district court’s criticism is incorrect.
    The independent peer review panel commented directly
    on the FWS’s analysis of the impact of CVP/SWP on P.
    forbesi and the BiOp’s conclusion that the abundance of P.
    forbesi “may vary inversely with export flow . . . and directly
    with outflow.” It stated: “The [p]anel agrees with this
    conceptual model and with the justification of its elements,
    which are well-supported.” The panel offered technical
    suggestions and then commented, “the figures meant to
    support this analysis are not convincing.” The panel then
    “suggest[ed] that this analysis be redone with the above
    considerations in mind. If [the] revised analysis does not
    show a substantial (not necessarily statistically significant)
    pattern, the analysis should be mentioned but the results
    dropped as quantitative metric from the EA.” (emphasis
    added). The FWS did exactly as the panel recommended. It
    100                  SAN LUIS V. JEWELL
    omitted the statistical analysis as justification for its
    conclusion.
    We cannot see the error in the FWS following the
    recommendation of the peer review panel. Moreover, the
    FWS had other reasons, explained in the record, for
    concluding that CVP/SWP operations had an effect on P.
    forbesi and that the abundance of P. forbesi indirectly affects
    the delta smelt. See BiOp at 184–85, 228. That it omitted a
    statistical study because it did not have sufficient data to
    justify it does not strike us as a “results-driven choice,” but as
    responsible science. Nothing in the ESA compelled the FWS
    to conduct the particular study the peer review panel thought
    inadequately supported by the data, and nothing in the peer
    review panel’s comments even hints that the statistics
    suggested a contrary conclusion—there is no evidence here
    to suggest that the FWS, in conspiracy with the peer review
    panel, was trying to hide evidence. Even if we thought that
    a “rigorous, large-scale study . . . would be preferable,” we
    have no authority to compel one: “in the absence of such a
    study,” even “credible anecdotal evidence” can “represent[]
    the best scientific . . . data available.” Nw. Ecosystem
    Alliance v. FWS, 
    475 F.3d 1136
    , 1147 (9th Cir. 2007)
    (internal quotation marks omitted).
    Like the peer review panel in question, we conclude that
    although the FWS’s analysis here is not without its
    limitations, it is “based upon the best available science.” See
    Nw. Ecosystem Alliance, 
    475 F.3d at 1147
    . Similarly, we are
    persuaded that the BiOp’s conclusion that Project operations
    indirectly affect the delta smelt by impacting the smelt food
    supply was “well supported.” We need not independently
    conclude that this conclusion is well supported to a
    “reasonable certainty.” It is sufficient that we conclude that
    SAN LUIS V. JEWELL                    101
    the BiOp’s conclusion was sufficiently supported such that
    the FWS did not arbitrarily and capriciously find this to be an
    indirect effect to a reasonable certainty.
    2. Project operations indirectly affect the smelt through
    water contamination
    Second, the BiOp explores the Project’s impact on water
    contamination and therefore, indirectly, on smelt population
    viability. The BiOp first concludes that water contamination
    poses a threat to the delta smelt. Smelt throughout the Delta
    are exposed to various pesticides and contaminants, which
    “may affect embryo survival or inhibit prey production.” The
    BiOp singles out ammonia released from a waste processing
    facility in Sacramento and pesticides from agricultural
    operations. BiOp at 153, 187, 237. The BiOp observes that
    “concern over contaminants in the Delta is not new” and
    refers to mercury, selenium, pesticides, herbicides,
    ammonium concentrations, and undiluted drainwater. BiOp
    at 187. Reclamation observes that the “delta smelt are highly
    sensitive to high levels of ammonia” and that such
    contaminants are detrimental to the health of the smelt
    population because they render smelt susceptible to disease.
    BiOp at 187–88.
    The BiOp concludes that Project operations will
    dangerously increase the impact of contaminants on the
    smelt. One reason is topographical: as Project operations
    constrain the smelt habitat to smaller rivers and estuaries, the
    smelt’s overall exposure to these contaminants, which result
    primarily from land runoff, increases. See BiOp at 153.
    Relatedly, when Project operations reduce overall suitable
    habitat, the impact of contaminants on the smelt in the
    remaining habitat become intensified. The BiOp analyzes
    102                  SAN LUIS V. JEWELL
    this latter effect in the context of recognizing the importance
    of fall X2 to delta smelt viability: The FWS described two
    “[p]otential mechanisms for the observed effect,” one of
    which was that “a more confined distribution may increase
    the impact of stochastic events that increase mortality rates of
    delta smelt . . . includ[ing] . . . anthropogenic effects such as
    contaminants.” BiOp at 234 (citing Sommer et al. 2007). One
    other harmful effect of Project operations, the FWS notes,
    comes from the flow created by Project pumping: Project-
    related flow “increase[s] exposure to many pesticides [during
    spawning].” BiOp at 153. This is because flows can
    “mobilize contaminants.” BiOp at 240.
    The district court concluded that “[i]t is not clear how the
    BiOp or any other document in the record links the impacts
    of contaminants to Project Operations.” San Luis & Delta-
    Mendota, 
    760 F. Supp. 2d at 942
    . This criticism is not well-
    founded. Although the FWS recognized that “contaminant
    loading and its ecosystem effects within the Delta are not well
    understood,” BiOp at 186, the fact that science must advance
    further before the complicated ecosystem interactions in the
    Bay-Delta are fully understood does not necessarily mean that
    the FWS failed to rely on the best available science, or that it
    arbitrarily and capriciously concluded that there was a
    reasonable certainty that Project operations will indirectly
    affect smelt through water contamination. Appellees would
    presumably have us hold that it is impossible for an agency
    to simultaneously recognize that some characteristics of an
    indirect effect “are not well understood” or are “highly
    uncertain,” and that it is reasonably certain that those indirect
    effects are harmful and will result from the actions at issue.
    We decline to do so. We are confident that if we returned the
    BiOp to the agency, we could help the agency improve it by
    “point[ing] out errors and missing information” and
    SAN LUIS V. JEWELL                     103
    “insist[ing] on additional detail.” Churchill Cnty. v. Norton,
    
    276 F.3d 1060
    , 1081 (9th Cir. 2001). But “[t]hat is not our
    role, of course.” 
    Id.
     Instead, we hold that the BiOp has
    sufficiently explained the harmful relation between Project
    operations, contaminants, and delta smelt such that the FWS
    did not arbitrarily and capriciously conclude to a reasonable
    certainty that Project operations contribute to harmful
    contaminant-related indirect effects.
    3. Project operations indirectly affect the smelt through
    the “other stressors” of predation, macrophytes, and
    microcystis
    As part of its analysis of the impacts of Project operations
    on the smelt, the BiOp discusses the effect of “other
    stressors”: “the multitude of factors that affect delta smelt
    population dynamics including predation, . . . aquatic
    macrophytes, and microcystis.” BiOp at 202. Because “[t]he
    extent to which these factors adversely affect delta smelt is
    related to hydrodynamic conditions in the Delta, which in
    turn are controlled to a large extent by CVP and SWP
    operations,” BiOp at 202, the BiOp’s analysis considers these
    “other stressors” when determining “the effects of proposed
    CVP/SWP operations on delta smelt,” BiOp at 203. We hold
    first that the BiOp’s conclusion that “hydrodynamic
    conditions driven or influenced by CVP/SWP operations . . .
    influence the dynamics of delta smelt interaction with these
    other stressors” was sufficiently supported in the record.
    BiOp at 202. The BiOp explicitly relied on outside scientific
    studies in concluding that Project operations “affect[] or
    control[]” some of these other stressors impacting delta smelt
    abundance. BiOp at 203. Second, having determined that
    Project operations likely affect the impact of “other stressors”
    104                 SAN LUIS V. JEWELL
    on the smelt, the BiOp considers the harmful effects of these
    other stressors on the smelt population.
    The district court faulted the FWS for failing to consider
    “available information,” San Luis & Delta-Mendota, 
    760 F. Supp. 2d at
    934–35, or “make a rational connection between
    the facts in the record and its conclusions,” 
    id. at 936
    . We
    disagree, and find the BiOp sufficiently thorough and hold
    that the FWS did not arbitrarily and capriciously reach this
    conclusion.
    a. Predation
    One stressor to the smelt is predation. As the BiOp
    acknowledged, there is much here that is unknown. It is
    known that in the 1960s, when the delta smelt were more
    plentiful, they were prey for striped bass, black crappie, and
    white catfish. BiOp at 183. The BiOp observed that “[i]t is
    unknown whether incidental predation by striped bass (and
    other lesser predators) represents a substantial source of
    mortality for delta smelt,” in part because the scarcity of
    smelt means that smelt have recently gone undetected in
    recent studies of predator stomach contents. BiOp at 183.
    The BiOp speculated that “[d]elta smelt may experience high
    predation mortality around water diversion where smelt are
    entrained and predators aggregate,” citing to an outside study
    showing that smelt eggs and larvae were prey for inland
    silversides. BiOp at 183. The BiOp also recognized the risks
    presented from other potential predators of smelt eggs and
    SAN LUIS V. JEWELL                             105
    larvae in such areas, including yellowfin goby, centrarchids,
    and Chinook salmon.41 BiOp at 183.
    After concluding that predation poses a harmful indirect
    effect to delta smelt population viability, the BiOp discusses
    the relation between Project operations and smelt predation.
    By shifting X2 further upstream, Project operations move
    smelt habitat to include more of these littoral areas (areas of
    the Bay-Delta close to shore), thereby increasing smelt
    exposure to predators. BiOp at 153. As the location of X2
    shifts towards new Bay-Delta regions that are rife with
    predators the smelt follow. Moreover, the BiOp notes that
    “[t]he Delta-wide increase in water transparency may have
    intensified predation pressures on delta smelt,” citing the
    “[w]ide documenta[tion],” including several specific studies,
    indicating that water clarity significantly influences predation
    of pelagic fishes, including many smelt species. BiOp at 183.
    The district court found this analysis lacking, specifically
    citing the FWS’s failure to explain whether striped bass
    predation on the smelt “should be considered significant.”
    San Luis & Delta-Mendota, 
    760 F. Supp. 2d at 934
    . Here, the
    district court was very specific: It faulted the BiOp for failing
    to “include any estimates of the effect of predation on the
    delta smelt population” when “[s]uch information was
    available” and was “decidedly contrary to BiOp findings.”
    
    Id.
     In support, the district court referenced a 1999 California
    41
    The BiOp considered whether delta smelt are affected by competition
    from other fish, and cited one study suggesting that they were. The BiOp
    did not rely on competition as a stressor, however, because “there is no
    empirical evidence to support the conclusion that competition between
    these species is a factor that influences the abundance of delta smelt in the
    wild.” BiOp at 183.
    106                  SAN LUIS V. JEWELL
    Department of Fish & Game report submitted to the FWS as
    part of an incidental take permit. 
    Id.
     (citing California Dep’t
    of Fish and Game, Conservation Plan for The California
    Department of Fish and Game Striped Bass Management
    Program (November 12, 1999)). We are not sure what the
    Fish & Game report adds, and we cannot see that the report
    is “decidedly contrary” to the FWS’s conclusions.
    The Fish & Game report stated that “the best available
    information yields imprecise, loosely constrained estimates
    of striped bass predation on delta smelt.” It said that there
    was considerable overlap between the delta smelt and striped
    bass, but that “striped bass rarely ate delta smelt,” likely
    because “delta smelt are surface oriented while striped bass
    tend to forage near the bottom.” Fish & Game estimated that
    striped bass were responsible for “an estimated annual
    consumption of about 5.3% of the delta smelt population.”
    We do not see the conflict between the Fish & Game report
    and the BiOp. The BiOp concluded that “[i]t is unknown
    whether incidental predation by striped bass . . . represents a
    substantial source of mortality for delta smelt.” BiOp at 183.
    The Fish & Game report is consistent with the FWS’s
    conclusion. If anything, the Fish & Game report might
    suggest that further study is required to see if the striped bass
    is a substantial source of mortality for the smelt. Although
    the BiOp cited post-1999 studies showing that the striped
    bass was not a significant predator of the delta smelt, if Fish
    & Game is correct (and current) in its estimates, a predator
    responsible for a 5.3 percent mortality rate of an endangered
    species might be significant. In any event, we fail to see its
    significance with respect to the conclusions of the BiOp. The
    BiOp concluded that predators—primarily fish other than the
    striped bass—were a potential threat to the delta smelt. More
    SAN LUIS V. JEWELL                     107
    broadly, we decline to review with a fine-toothed comb the
    studies on which the FWS relied in reaching its conclusions.
    b. Aquatic Macrophytes
    Another stressor noted in the BiOp is aquatic
    macrophytes. Macrophytes—aquatic plants that grow in or
    near water—have extensively colonized the interior Delta
    over the past two decades. BiOp at 182. As the BiOp notes,
    research suggests that these macrophytes have “altered fish
    community dynamics in the Delta, including increasing
    habitat for centrarchid fishes including largemouth bass,
    reducing habitat for native fishes, and supporting a food web
    pathway for centrarchids and other littoral fishes.” BiOp at
    182 (citations to scientific studies omitted). These effects
    impact smelt both directly and indirectly. Submerged aquatic
    vegetation can overwhelm littoral habitats, such as inter-tidal
    shoals and beaches, that serve as delta smelt spawning
    locations, thereby rendering them unsuitable for spawning.
    BiOp at 182. Moreover, macrophytes trap suspended
    sediment and therefore reduce water turbidity, which has
    contributed to a decrease in both juvenile and adult smelt
    habitat while increasing the available habitat for fish that prey
    on smelt. BiOp at 182–83 (citing Feyrer et al. 2007 and
    Nobriga et al. 2008 in support). This decreased turbidity also
    may facilitate the predation of delta smelt while hampering
    the smelt’s own feeding, thereby further harming smelt
    population viability. BiOp at 183.
    As the BiOp notes, hydrologic conditions and water
    temperature play a significant role in macrophyte
    colonization of the Delta. BiOp at 182. The FWS concludes
    that it is “likely” that Project operations’ impact on Bay-Delta
    hydrologic conditions and reduction of seasonal flushing
    108                 SAN LUIS V. JEWELL
    flows exacerbate the spread of macrophytes in the Bay-Delta.
    BiOp at 277. Flushing flows are known to lead to “abrupt
    changes in flow and turbidity.” BiOp at 146. Indeed, the
    FWS found that “[a]vailable information is inconclusive
    regarding the extent, magnitude and pathways by which delta
    smelt may be affected by these stressors independent of
    CVP/SWP operations.” BiOp at 277.
    The district court was also not persuaded by this analysis,
    finding that “[a]lthough a connection [between Project
    operations and macrophytes] may exist, the record does not
    reflect any discussion, nor have the parties pointed to any
    study, connecting ‘seasonal flushing flows . . . the natural
    frequency of upstream and downstream movement of the
    LSZ, and lengthen[ed] upstream shifts of the LSZ’ to the
    presence of any aquatic macrophyte.” San Luis & Delta-
    Mendota, 
    760 F. Supp. 2d at
    935–36. Again, we disagree.
    The BiOp set forth several plausible explanations for how
    Project operations will increase the detrimental impact of
    macrophytes on delta smelt viability, and cited studies in
    support. See BiOp at 146, 182–83, 277. That the BiOp did
    not, as the district court requests, point to a study directly
    addressing the Project’s effect on Bay-Delta macrophytes
    does not render the FWS’s conclusions unreasonable or
    unsupported: The FWS has drawn rational conclusions from
    the best available science, and, consequently, we hold that the
    BiOp’s determination that it is reasonably certain that
    macrophytes will indirectly affect delta smelt is not arbitrary
    and capricious. It is not our job to task the FWS with filling
    the gaps in the scientific evidence. We must respect the
    agency’s judgment even “in the face of uncertainty.” Ariz.
    Cattle Growers Ass’n v. Salazar, 
    606 F.3d 1160
    , 1164 (9th
    Cir. 2010).
    SAN LUIS V. JEWELL                     109
    c. Microcystis
    Microcystis aeruginosa is a cyanobacterium that produces
    toxins throughout its life cycle, with toxin concentrations
    sharply increasing when the bacteria population dies, usually
    in September or October. BiOp at 372. These high toxin
    levels present a threat to the delta smelt and, as the BiOp
    recognizes, high microcystis toxin levels have been associated
    with low delta smelt abundances. BiOp at 372. Microcystis
    can directly “pose animal and human health risks if contacted
    or ingested directly,” although it does not appear that current
    concentrations are sufficiently severe to threaten smelt. BiOp
    at 186. Rather, microcystis’s primary threat to the smelt is
    indirect, as “it appears that M. aeruginosa is toxic to
    copepods that delta smelt eat.” BiOp at 186 (citing an outside
    scientific study). There is also concern that microcystis
    “could out-compete diatoms[, a rich food source for
    zooplankton,] for light and nutrients.” BiOp at 186. As the
    BiOp notes, however, more studies are needed, and, in fact,
    “are underway to determine if zooplankton production is
    compromised during M. aeruginosa blooms to an extent that
    is likely to adversely affect delta smelt.” BiOp at 186.
    As the BiOp also discusses, CVP/SWP operations are
    likely to increase the harmful impact of microcystis on delta
    smelt because “[l]ow flow conditions are among the factors
    associated with Microcystis blooms.” BiOp at 372. By
    reducing flows, Project operations would cause “larval and
    juvenile delta smelt . . . [to] remain in the Central and South
    Delta, where they could . . . succumb to predation or
    microcystis blooms.” BiOp at 224. Overall, Microcystis
    “reduce[s] habitat suitability.” BiOp at 373.
    110                 SAN LUIS V. JEWELL
    The district court found that the BiOp “makes no
    connection whatsoever between microcystis . . . and
    continued CVP and SWP operation” and that “[g]iven that the
    impacts of regulating Project Operations are so consequential,
    such unsupported attributions (a result in search of a
    rationale) are unconscionable.” San Luis & Delta-Mendota,
    
    760 F. Supp. 2d at 936
    . Again, we disagree. The FWS has
    proposed several plausible evidence-based hypotheses
    explaining the harmful Project-related impact of
    microcystis on delta smelt. The BiOp candidly acknowledges
    that additional studies in this area are underway. That
    CVP/SWP operations are not the only dynamic force acting
    on the Bay-Delta does not render the BiOp’s recognition of
    the inherent uncertainty associated with the highly
    interdependent ecosystem unreasonable. We should not deter
    agencies from recognizing the limitations of either science or
    their own knowledge. In this instance, the evidence linking
    Project operations, Bay-Delta hydrologic conditions, and
    microcystis harms is sufficient that we hold that the FWS’s
    microcystis conclusions were not arbitrary and capricious.
    E. The FWS Is Not Required to Support the “Non-Jeopardy”
    Elements of its RPA
    When the Secretary determines that an agency action will
    cause jeopardy to, or an adverse habitat modification of, an
    endangered or threatened species, the Secretary “shall suggest
    those reasonable and prudent alternatives which he believes
    would not [jeopardize the species or adversely modify its
    habitat] and can be taken by the Federal agency or applicant
    in implementing the agency action.” 
    16 U.S.C. § 1536
    (b)(3)(A); see also 
    50 C.F.R. §§ 402.14
    (h)(3),
    402.14(g)(5). The FWS’s regulations further explain its duty
    SAN LUIS V. JEWELL                    111
    under the ESA. The regulations define “reasonable and
    prudent alternatives”—RPAs—as
    alternative actions identified during formal
    consultation [1] that can be implemented in a
    manner consistent with the intended purpose
    of the action, [2] that can be implemented
    consistent with the scope of the Federal
    agency’s legal authority and jurisdiction, [3]
    that is economically and technologically
    feasible, and [4] that the Director believes
    would avoid the likelihood of jeopardizing the
    continued existence of listed species or
    resulting in the destruction or adverse
    modification of critical habitat.
    
    50 C.F.R. § 402.02
    . Element [4] in § 402.02 is commonly
    referred to as the “jeopardy” factor; elements[1] through [3]
    are referred to as the “non-jeopardy” factors. The FWS’s
    Consultation Handbook explains further: “If the services
    conclude that certain alternatives are available that would
    avoid jeopardy and adverse modification, but such
    alternatives fail to meet one of the other three elements in the
    definition of ‘reasonable and prudent alternative,’ the
    Services should document the alternative in the biological
    opinion to show it was considered during the formal
    consultation process.” U.S. Fish & Wildlife Serv. & Nat’l
    Marine Fisheries Serv., ESA at 4–41 (March 1998), Section
    7 Consultation Handbook, available at http://www.fws.gov/
    endangered/esa-library/pdf/CH4.pdf (last visited July 27,
    2013) (second emphasis added). Thus, according to the
    Consultation Handbook, if a draft alternative fails to meet one
    of the non-jeopardy “elements” of a valid RPA, the Service
    should provide documentation to show that it considered
    112                  SAN LUIS V. JEWELL
    alternatives during consultation. Id. We have previously
    afforded Skidmore deference to the FWS’s Consultation
    Handbook. See Ariz. Cattle Growers’ Ass’n, 
    606 F.3d at 1165
     (concluding that “[t]he definition in the handbook
    appears to be the result of the agency's considered judgment
    and . . . we are persuaded [that it is a reasonable one entitled
    to deference]”); see also Skidmore v. Swift & Co., 
    323 U.S. 134
     (1944).
    Referring to the non-jeopardy factors, the district court
    found that the FWS “has articulated absolutely no connection
    between the facts in the record and the required conclusion
    that the RPA is (1) consistent with the purpose of the
    underlying action; (2) consistent with the action agency’s
    authority; and (3) economically and technologically feasible.”
    San Luis & Delta-Mendota, 
    760 F. Supp. 2d at
    956–57. The
    court continued:
    the APA requires, and the public is entitled
    under the law to receive, some exposition in
    the record of why the agency concluded (if it
    did so at all) that all four regulatory
    requirements for a valid RPA were satisfied.
    The RPA Actions manifestly interdict the
    water supply for domestic human
    consumption and agricultural use for over
    twenty million people who depend on the
    Projects for their water supply. “Trust us” is
    not acceptable.        FWS has shown no
    inclination to fully and honestly address water
    supply needs beyond the species despite the
    fact that its own regulation requires such
    consideration.
    SAN LUIS V. JEWELL                   113
    San Luis & Delta-Mendota, 
    760 F. Supp. 2d at 957
    . Because
    the FWS had failed to explain why it chose its RPAs, “to the
    exclusion of implementing less harmful alternatives,” the
    district court remanded to the FWS. 
    Id.
     Put more simply, the
    district court found that both the FWS’s regulation and the
    APA required the FWS to engage in a record exposition of
    the non-jeopardy factors, and that the FWS did not do so.
    We disagree both with the district court’s legal analysis
    and with its reading of the record.
    First, contrary to the district court’s conclusion, the
    FWS’s “own regulation” does not require the FWS to address
    the non-jeopardy factors. San Luis & Delta-Mendota, 
    760 F. Supp. 2d at 957
    . Nothing in § 402.02 obligates the FWS to
    address the non-jeopardy factors when it proposes RPAs.
    Section 402.02 is a definitional section; it is defining what
    constitutes an RPA, not setting out hoops that the FWS must
    jump through. See 
    50 C.F.R. § 402.02
    ; see also 
    id.
     at
    § 402.14(g)(5) (the FWS shall “discuss [with an agency] . . .
    the availability of reasonable and prudent alternatives”);
    302.02(h)(3) (“A ‘jeopardy’ biological opinion shall include
    reasonable and prudent alternatives if any.”). Moreover, the
    Consultation Handbook implies that no such discussion is
    necessary. As the Handbook notes:
    [Although] it is imperative that the opinion
    contain a thorough explanation of how each
    component of the [reasonable and prudent]
    alternative is essential to avoid jeopardy
    and/or adverse modification[,] . . . [i]f the
    Services conclude that certain alternatives are
    available that would avoid jeopardy and
    adverse modification, but such alternatives
    114                    SAN LUIS V. JEWELL
    fail to meet one of the other three elements in
    the definition of ‘reasonable and prudent
    alternative,’ the Services should document the
    alternative in the biological opinion to show it
    was considered during the formal consultation
    process.
    Section 7 Consultation Handbook, available at
    http://www.fws.gov/endangered/esa-library/pdf/CH4.pdf (last
    visited July 1, 2013); see also 
    50 C.F.R. § 402.14
    (h)(3) (“If
    the Service is unable to develop such [reasonable and
    prudent] alternatives, it [must] indicate that to the best of its
    knowledge there are no reasonable and prudent
    alternatives.”). In other words, a “thorough” documentation
    of jeopardy/adverse modification in the BiOp is always
    required, whereas documentation of the non-jeopardy factors
    is only required when the RPA fails to meet a non-jeopardy
    factor.
    We fail to see anywhere that the FWS has required itself
    to provide an explanation of the non-jeopardy factors when
    it lays out an RPA. We may not “impose on the agency [our]
    own notion of which procedures are ‘best’ or most likely to
    further some vague, undefined public good. Nor may we
    impose procedural requirements [not] explicitly enumerated
    in the pertinent statutes.” McNair, 
    537 F.3d at 993
     (internal
    quotation marks and citations omitted).42
    42
    We note that the Fourth Circuit recently remanded a BiOp to the FWS
    for failure to evaluate an RPA for its economic and technological
    feasibility. Dow AgroSciences, 707 F.3d at 474–75. We do not read Dow
    to require the FWS to address economic and technological feasibility as
    a procedural matter. As we read Dow, the court was concerned that the
    FWS had imposed an especially onerous requirement without any thought
    for whether it was feasible. Id. at 475 (RPA would prohibit pesticide
    SAN LUIS V. JEWELL                            115
    Second, the APA does not, as the district court held,
    require the FWS to address the non-jeopardy factors in this
    case. See San Luis & Delta-Mendota, 
    760 F. Supp. 2d at 957
    .
    Under the APA, the Supreme Court has held that agency
    decisions that “entirely fail[] to consider an important aspect
    of the problem” are arbitrary and capricious. Motor Vehicle
    Mfrs. Ass’n of U.S., Inc. v. State Farm Mut. Auto Ins. Co.,
    
    463 U.S. 29
    , 43 (1983). We have held that whether an RPA
    will prevent jeopardy or adverse modification of critical
    habitat is “an important aspect of the problem.” See, e.g.,
    Wild Fish Conservancy v. Salazar, 
    628 F.3d 513
    , 522–23 (9th
    Cir. 2010) (finding a BiOp that failed to explain how the RPA
    avoided jeopardy arbitrary and capricious); Pacific Coast
    Fed’n of Fishermen’s Ass’ns v. U.S. Bureau of Reclamation,
    
    426 F.3d 1082
    , 1091 (9th Cir. 2005) (same). But the
    jeopardy factor in the RPA is independently demanded by the
    ESA itself. Section 1536(a)(2) requires that each federal
    agency shall “insure that any action . . . is not likely to
    jeopardize” the species or its habitat. 
    16 U.S.C. § 1536
    (a)(2).
    This includes the FWS, which must warrant that its RPA
    “would not violate [§ 1536(a)(2)].”                
    16 U.S.C. § 1536
    (b)(3)(a). That is, the FWS, in the course of proposing
    an RPA, must insure that the RPA does not jeopardize the
    species or its habitat. We can find no similar requirement in
    the ESA that the FWS address the remaining three non-
    jeopardy factors. If the ESA does not require it, we are
    extremely reluctant to read such a requirement into the APA.
    applications “within 500 feet (for ground applications) and 1,000 feet (for
    aerial applications) of any waterway that is connected, directly or
    indirectly, at any time of the year, to any water body in which salmonids
    might be found at some point.” (emphases in original)).
    116                 SAN LUIS V. JEWELL
    Moreover, we are persuaded that the district court misread
    what the economic feasibility factor addresses. The court
    faulted the FWS for not accounting for the cost of
    “interdict[ing] the water supply for domestic human
    consumption and agricultural use for over twenty million
    people who depend on the Projects for their water supply.”
    San Luis & Delta-Mendota, 
    760 F. Supp. 2d at 957
    . This
    misreads the ESA and its implementing regulations. Section
    402.02 is only concerned with the economic and
    technological feasibility of the RPA. That is, the FWS must
    consider whether its proposed alternative is financially and
    technologically possible. Those two considerations—
    economics and technology—are constraints on what
    measures the FWS can recommend to the agency as an
    alternative to ceasing the activity entirely. To put it into
    perspective in this case: Reclamation has consulted with the
    FWS because it has legitimate concerns whether its continued
    CVP activities may jeopardize the smelt or its habitat. When
    the FWS concludes that Reclamation’s continued activities
    will jeopardize the smelt then, presumptively, Reclamation
    may not take or continue such activities. See Nat’l Assn of
    Home Builders v. Defenders of Wildlife, 
    551 U.S. 644
    , 652
    (2007) (“Following the issuance of a ‘jeopardy’ opinion, the
    agency must either terminate the action, implement the
    proposed alternative, or seek an exemption from the Cabinet-
    Level Endangered Species Committee . . . .”). In this case, of
    course, terminating Reclamations’ CVP-related activities is
    unthinkable. The whole point of the “reasonable and prudent
    alternative” is for the FWS to suggest what Reclamation can
    do to avoid such a result. The regulation identifies
    “economic and technological feasibility” as factors because
    these go to whether the RPA “can be taken by the Federal
    agency . . in implementing the agency action,” 
    16 U.S.C. § 1536
    (b)(3)(A) (emphasis added), not to whether restricting
    SAN LUIS V. JEWELL                       117
    CVP activities will affect its consumers.43 The “economic
    and technological feasibility” factor does not address the
    downstream economic impacts of Reclamation being unable
    to continue its CVP operations as it has done in the past. As
    important and consequential as the question is, the FWS is
    not responsible for balancing the life of the delta smelt
    against the impact of restrictions on CVP/SWP operations.
    That balance has already been struck by Congress in the ESA
    and the Central Valley Project Improvement Act. See CVPIA
    § 3406(b), Pub. L. No. 102-575, 
    106 Stat. 4600
    , 4714 (stating
    that the Secretary of the Interior is to “operate the Central
    Valley Project to meet all obligations under State and Federal
    law, including but not limited to the Federal Endangered
    Species Act, 
    16 U.S.C. § 1531
     et seq”); Tenn. Valley Auth.,
    
    437 U.S. at 185
     (holding that the ESA reflects “a conscious
    decision by Congress to give endangered species priority over
    the ‘primary missions’ of federal agencies”). Accordingly,
    the FWS’s duty is to opine on the viability of the smelt and
    “to halt and reverse the trend toward species extinction,
    whatever the cost.” 
    Id. at 184
     (emphasis added).
    Even if the APA did require the FWS to consider the non-
    jeopardy factors, the record shows that the FWS has
    sufficiently considered them. See Motor Vehicle Mfrs. Ass’n
    of U.S., Inc, 
    463 U.S. at 43
     (holding that insufficient
    consideration for purposes of APA arbitrary and capricious
    review is an “entire[] fail[ure] to consider”). Although the
    FWS’s consideration of the non-jeopardy factors could
    certainly have been even more exhaustive, or stated more
    expressly, its determination that the RPA satisfied the non-
    43
    Neither the parties nor the district court argue that the RPAs
    themselves (and their proposed Actions) are not economically and
    technologically feasible.
    118                 SAN LUIS V. JEWELL
    jeopardy factors “may be reasonably discerned” from the
    record, and therefore should be upheld. 
    Id.
     (holding that even
    “a decision of less than ideal clarity” should be upheld in
    such circumstances). Application of the non-jeopardy factors
    in this case is really quite straightforward. See 
    50 C.F.R. § 402.02
    . First, the record shows that the RPA is consistent
    with the purpose of the underlying action. The document that
    was prepared as a basis for consultation, Reclamation’s
    biological assessment (BA), identified the purpose of this
    action to be “operat[ing] the [Projects] to divert, store, re-
    divert, and convey CVP and SWP . . . water consistent with
    applicable law.” The RPAs—which largely deal with
    regulating the water that CVP/SWP export from the Delta-
    Bay—do not require any major changes in the way
    Reclamation runs its operations. Second, and similarly,
    the record indicates that the RPA can be implemented
    “consistent with the scope of the Federal agency’s legal
    authority.” Both the BA and the BiOp discuss the extent of
    Reclamation’s authority.        See, e.g., BiOp at 21–25
    (Reclamation’s obligations under its Coordinated Operations
    Agreement with DWR). Finally, there is support in the
    record for the FWS’s conclusion that the RPA is both
    technologically and economically feasible. We think this is
    nearly self-evident. The RPA closely resembles measures in
    the interim remedial order, the feasibility of which was
    proven in its mid-December 2007 through December 2008
    implementation. BiOp at 327–28. Additionally, RPA
    incorporates feasibility-related comments that were made on
    a draft RPA from Reclamation and DWR. Again, the RPAs
    propose regulatory changes in what Reclamation does on a
    day-to-day basis, but the RPAs do not require major changes
    affecting Reclamation’s ability—financially or
    technologically—to comply with the RPAs.
    SAN LUIS V. JEWELL                          119
    In sum, we disagree with the district court’s determination
    that the FWS’s own regulation and the APA require the FWS
    to explain that the RPA satisfies § 402.02 non-jeopardy
    factors. Alternatively, we hold that the FWS’s consideration
    of these factors may be reasonably discerned from the record
    to satisfy any explanation requirements.44
    V. CROSS-APPEAL
    The appellees raise three claims of error in the district
    court: that the FWS violated the ESA by not separating
    discretionary from nondiscretionary actions when it set the
    environmental baseline; that Reclamation acted arbitrarily
    and capriciously when it accepted the BiOp; and that the
    FWS and Reclamation failed to prepare an environmental
    impact statement, as required by NEPA. We consider each in
    turn.
    A. Segregating Discretionary From Nondiscretionary
    Actions
    When determining whether an agency’s operations are
    likely to jeopardize the continued existence of a listed species
    or result in the destruction or adverse modification of a
    critical habitat, the FWS must “[e]valuate the effects of the
    action and cumulative effects on the listed species or critical
    44
    We also hold that the FWS need not explain why it chose the RPA
    measures over “less harmful alternatives.” San Luis & Delta-Mendota,
    
    760 F. Supp. 2d at 957
    . In Southwest Center for Biological Diversity, we
    held that “under the ESA, the Secretary was not required to explain why
    he chose one RPA over another, or to justify his decision based solely on
    apolitical factors.” 143 F.3d at 523. Consequently, we do not agree with
    the district court that such a failure demands remand to the agency. San
    Luis & Delta-Mendota, 
    760 F. Supp. 2d at 957
    .
    120                  SAN LUIS V. JEWELL
    habitat.” 
    50 C.F.R. § 402.14
    (g)(3). This evaluation requires
    determining an “environmental baseline,” which “does not
    include the effects of the action under review,” and then
    adding the direct and indirect effects of the proposed federal
    action to determine whether that action will jeopardize a
    listed species. See 
    50 C.F.R. § 402.02
    ; Section 7 Consultation
    Handbook, available at http://www.fws.gov/endangered/esa-
    library/pdf/CH4.pdf; see also Interangency Cooperation—
    Endangered Species Act of 1973 as Amended; Final Rule, 
    51 Fed. Reg. 19,926
    , 19,932 (June 3, 1986) (noting that the
    environmental baseline “serve[s] as the baseline for
    determining the effects of the action on the species or critical
    habitat”).
    In Home Builders, the Supreme Court held that the
    consultation requirement in ESA § 7(a)(2), 
    16 U.S.C. § 1536
    (a)(2), does not “impliedly repeal[] nondiscretionary
    statutory mandates, even when they might result in some
    agency action.” Nat’l Ass’n of Home Builders, 
    551 U.S. at 665
    . In that case, the Clean Water Act required the EPA to
    transfer certain permitting powers to state authorities if nine
    criteria were satisfied. 
    33 U.S.C. § 1342
    (b). In accordance
    with the ESA § 7(a)(2), the EPA consulted with the FWS.
    The Service found that the transfer would not have any direct
    effect on any species in Arizona listed under the ESA. The
    FWS, however, was concerned that once EPA transferred
    permitting authority to Arizona, the ESA would no longer
    apply to permitting decisions, and Arizona could issue
    permits without regard to listed species. The FWS concluded
    that the transfer might have indirect effects on the species,
    although no decision or action of EPA was in question, other
    than the transfer of permitting authority. Id. at 653–54. The
    Court held that the ESA did not function as an additional
    constraint on the EPA’s duty to transfer permitting authority
    SAN LUIS V. JEWELL                     121
    to Arizona: “[Section] 7(a)(2)’s no-jeopardy duty covers only
    discretionary agency actions and does not attach to actions
    . . . that an agency is required by statute to undertake once
    certain specified triggering events have occurred.” Id. at 669.
    Relying on Home Builders, San Luis & Delta-Mendota
    Water Authority asserts that “[a]s part of this [§ 7(a)(2)]
    analysis, the FWS must, among other things, distinguish
    between the discretionary and nondiscretionary actions of an
    operation, so that only the discretionary actions are
    considered as effects of the agency action.” This argument
    was considered and rejected by the district court. See San
    Luis & Delta-Mendota, 
    760 F. Supp. 2d at
    947–48. The
    district court reasoned that “Home Builders addressed
    whether the section 7 consultation obligation attaches to a
    particular agency at all.” San Luis & Delta-Mendota, 
    760 F. Supp. 2d at 948
    . It did not, however, “address whether, once
    section 7 consultation is triggered, the jeopardy analysis must
    separately identify and segregate discretionary from non-
    discretionary actions, relegating the non-discretionary actions
    to the environmental baseline.” 
    Id.
     (emphasis removed).
    We agree with the district court’s analysis that Home
    Builders does not require the agency to segregate
    discretionary from non-discretionary actions when it
    considers the environmental baseline. Home Builders dealt
    only with whether § 7(a)(2) applies. The real question after
    Home Builders is what counts as a non-discretionary action,
    to which § 7(a)(2) does not apply.
    We addressed this question in National Wildlife
    Federation v. National Marine Fisheries Service, 
    524 F.3d 917
     (9th Cir. 2008) (“NWF”). In NWF, the National Marine
    Fisheries Service (NMFS) had issued a BiOp on the impacts
    122                 SAN LUIS V. JEWELL
    of the operation of the Federal Columbia River Power System
    (FCRPS) on a listed species. 
    Id. at 921
    .
    The 2004 BiOp’s jeopardy analysis included
    in the environmental baseline for the proposed
    action the existing FCRPS, various
    supposedly nondiscretionary dam operations,
    and all past and present impacts from
    discretionary operations. . . . NMFS also
    found, though, that certain aspects of FCRPS
    operations—such as operations relating to
    irrigation, flood control, and power
    generation—were nondiscretionary, given the
    dams’ existence, and that those aspects
    should not be considered part of the action
    under ESA review.
    
    Id. at 926
     (emphasis added). The agency “segregated its
    analysis, first evaluating whether the proposed agency
    action—consisting of only the proposed discretionary
    operation of the FCRPS—would have an appreciable net
    effect on a species.” 
    Id.
     The agency did this “instead of
    assessing whether the listed fish would be jeopardized by the
    aggregate of the proposed agency action, the environmental
    baseline, cumulative effects, and current status of the
    species.” 
    Id.
    This approach, we held, was incorrect: “NMFS may not
    avoid determining the limits of the action agencies’ discretion
    by using a reference operation to sweep so-called
    ‘nondiscretionary’ operations into the environmental
    baseline, thereby excluding them from the requisite ESA
    jeopardy analysis.” 
    Id. at 929
    . We distinguished NWF from
    Home Builders on the basis of the specificity of the mandate
    SAN LUIS V. JEWELL                          123
    in question. “[I]n the present case Congress has imposed
    broad mandates, rather than directing the agency to take
    specific actions, and the agencies are perfectly capable of
    simultaneously obeying Section 7 and those mandates.” 
    Id. at 928
    . We repeated that “in contrast [to Home Builders,]
    Congress has imposed broad mandates which do not direct
    agencies to perform any specific nondiscretionary actions, but
    rather, are better characterized as directing the agencies to
    achieve particular goals.” 
    Id. at 928
    . Thus, “while the goals
    themselves may be mandatory, the agencies retain
    considerable discretion in choosing what specific actions to
    take in order to implement them.” 
    Id. at 929
    . “‘[A]n agency
    cannot escape its obligation to comply with the ESA merely
    because it is bound to comply with another statute that has
    consistent, complementary objectives.’” 
    Id.
     (quoting
    Washington Toxics Coal. v. EPA, 
    413 F.3d 1024
    , 1032 (9th
    Cir. 2005)).
    The Water Authority has not pointed us to any statutory
    obligation that Congress has imposed on Reclamation that is
    both mandatory and inconsistent with its obligations under
    the ESA.45 Like the FCRPS in NWF, Reclamation has a very
    broad mandate. Moreover, Congress has stated, as clearly as
    it can, that Reclamation is to administer its obligations to the
    CVP consistent with the mandates of the ESA. CVPIA,
    § 3406(b), 106 Stat. at 4714 (stating that the Secretary of the
    Interior is to “operate the Central Valley Project to meet all
    obligations under State and Federal law, including but not
    45
    The Water Authority has pointed us to water contracts between
    Reclamation and wildlife refuge contractors, water exchange contracts
    with senior water rights holders, and a decision of the California State
    Water Resources Control Board. These do not approach the statutory
    mandate that the Court found EPA was under in Home Builders.
    124                  SAN LUIS V. JEWELL
    limited to the Federal Endangered Species Act, 
    16 U.S.C. § 1531
     et seq.”).
    B. Reclamation Did Not Violate the ESA by Accepting the
    2008 BiOp
    The Water Authority argues that Reclamation committed
    an independent violation of the ESA by relying on the BiOp.
    See Defenders of Wildlife, 420 F.3d at 976 (noting that
    “[a]rbitrarily and capriciously relying on a faulty Biological
    Opinion violates [the action agency’s independent and
    substantive] duty” (emphasis added)). Because we do not
    believe the 2008 BiOp to be arbitrary and capricious, we join
    the district court in declining to find that Reclamation’s
    reliance on the BiOp was arbitrary and capricious. See San
    Luis & Delta-Mendota, 
    760 F. Supp. 2d at
    966–67.
    C. Application of NEPA to the FWS and Reclamation
    NEPA requires that “to the fullest extent possible . . . all
    agencies of the Federal Government shall” complete an
    environmental impact statement (EIS) in connection with
    “every recommendation or report on proposals for legislation
    and other major Federal actions significantly affecting the
    quality of the human environment.” 
    42 U.S.C. § 4332
    (2)(C).
    The agency may begin by preparing an environmental
    assessment (EA). 
    40 C.F.R. §§ 1501.4
    (a)–(c); 1508.9. It may
    then issue a finding of no significant impact (FONSI) rather
    than completing an EIS if the EA reveals that the action in
    question “will not have a significant effect on the human
    environment.” 
    40 C.F.R. §§ 1501.4
    (e); 1508.13.
    In this case, neither the FWS nor Reclamation prepared an
    EA or an EIS. We are thus confronted with two questions
    SAN LUIS V. JEWELL                          125
    concerning the scope of NEPA’s requirement that agencies
    produce an EA and, if necessary, an EIS. First, was the
    FWS’s issuance of the BiOp a “major Federal action[]
    significantly affecting the quality of the human environment”
    that imposed on the FWS an obligation to comply with
    NEPA? And second, was Reclamation’s provisional adoption
    and implementation of the BiOp a “major Federal action[]
    significantly affecting the quality of the human environment”
    that imposed on Reclamation an obligation to comply with
    NEPA?46
    Before the district court, the plaintiffs initially alleged that
    the FWS violated NEPA by failing to prepare an EIS when
    issuing the 2008 BiOp. In their first amended complaint, the
    San Luis plaintiffs further asserted that Reclamation violated
    NEPA by accepting and implementing the BiOp without
    completing an EIS. In three of the five consolidated cases,
    the plaintiffs moved for summary judgment on their claims
    that the FWS and Reclamation failed to comply with NEPA.
    The defendant-intervenors, including NRDC, filed a cross-
    motion for summary judgment, arguing that the agencies
    were not obligated to adhere to NEPA in issuing or
    implementing the BiOp. In November 2009, the district court
    issued its decision on the parties’ cross-motions for summary
    judgment on the NEPA issues. San Luis & Delta-Mendota
    Water Auth. v. Salazar, 
    686 F. Supp. 2d 1026
     (E.D. Cal.
    2009). The district court observed that “[i]t is a close call
    46
    We review an agency’s decision that it need not prepare an EIS for
    “reasonableness.” See Northcoast Envtl. Ctr. v. Glickman, 
    135 F.3d 660
    ,
    667 (9th Cir. 1998) (“Here, we have a threshold question of NEPA
    applicability. The Secretaries have not prepared an EIS or EA . . .
    contending that NEPA does not apply . . . . We hold the less deferential
    standard of ‘reasonableness’ applies to threshold agency decisions that
    certain activities are not subject to NEPA’s procedures.”).
    126                 SAN LUIS V. JEWELL
    whether FWS’s issuance of the BiOp and its RPA under these
    circumstances” requires the preparation of an EIS pursuant to
    NEPA. 
    Id. at 1044
    . It concluded that “[t]his call need not be
    made, because Reclamation, the agency with the ultimate
    authority to implement the RPA, is now joined as a party,
    whose actions must be evaluated under NEPA.” 
    Id.
     The
    court granted summary judgment in favor of the plaintiffs on
    their claim against Reclamation, concluding “that
    Reclamation violated NEPA by failing to perform any NEPA
    analysis prior to provisionally adopting and implementing the
    2008 BiOp and its RPA.” 
    Id. at 1051
    .
    In a subsequent motion for summary judgment, the
    plaintiffs again asserted that the FWS violated NEPA by not
    issuing an EIS along with the BiOp. The district court
    remarked that “[t]his was an attempt to re-argue and re-frame
    arguments previously decided” because the district court’s
    “prior NEPA rulings determined that Reclamation bears the
    NEPA responsibility in this case.” San Luis & Delta-
    Mendota, 
    760 F. Supp. 2d at 965
    . The defendants filed an
    opposition and cross-motion for summary judgment, urging
    the district court to reaffirm that the FWS did not need to
    comply with NEPA in issuing the BiOp. The district court
    denied the plaintiffs’ motion and granted the defendants’
    motion with respect to the NEPA claims against the FWS. 
    Id. at 966
    .
    On appeal, the plaintiffs argue that both the FWS and
    Reclamation must comply with NEPA. The federal
    defendants contend that the FWS need not comply with
    NEPA because Reclamation will complete an EIS. And
    NRDC takes the position that neither the issuance of the BiOp
    by the FWS nor the acceptance and implementation of the
    BiOp by Reclamation triggers obligations under NEPA.
    SAN LUIS V. JEWELL                          127
    We affirm the district court’s judgment with respect to the
    NEPA claims. First, we hold that, under these circumstances,
    NEPA does not require the FWS to prepare an EIS in
    conjunction with the issuance of the BiOp. Second, we hold
    that Reclamation’s provisional adoption and implementation
    of the BiOp triggered its obligation to comply with NEPA.
    We therefore affirm the district court’s order remanding to
    Reclamation so that it can complete an EIS evaluating the
    effects of its adoption and implementation of the BiOp.47
    1. Application of NEPA to the FWS
    We first consider whether the FWS’s issuance of the
    BiOp was a “major Federal action[] significantly affecting the
    quality of the human environment” such that the FWS was
    obligated to complete an EIS. A “[m]ajor federal action
    includes actions with effects that may be major and which are
    potentially subject to Federal control and responsibility.”
    
    40 C.F.R. § 1508.18
    . The regulations offer several categories
    of major federal actions, including “[a]doption of formal
    plans, such as official documents prepared or approved by
    federal agencies which guide or prescribe alternative uses of
    Federal resources, upon which future agency actions will be
    based” and “[a]pproval of specific projects, such as
    47
    Reclamation provided notice of its intent to prepare an EIS on March
    28, 2012. See Remanded Biological Opinions on the Coordinated Long-
    Term Operation of the Central Valley Project and State Water Project:
    Notice of Intent to Prepare an Environmental Impact Statement and Notice
    of Scoping Meetings, 
    77 Fed. Reg. 18858
    -02 (March 28, 2012). The
    district court continues to actively manage Reclamation’s deadline for
    completing the EIS process. See Memorandum Decision and Order
    Regarding Motion to Extend Remand Schedule, Consolidated Delta Smelt
    Cases, No. 1:09-cv-00407(E.D. Cal. Apr. 9, 2013), ECF No. 1106.
    128                  SAN LUIS V. JEWELL
    construction or management activities located in a defined
    geographic area.” 
    Id.
     at § 1508.18(b)(2), (4).
    The federal defendants argue that the FWS, in its capacity
    as a consulting agency under Section 7 of the ESA, is merely
    offering its opinions and suggestions to Reclamation, which,
    as the action agency, ultimately decides whether to adopt or
    approve the plan. This view is well supported by the statute,
    regulations, and our case law. Section 7(b) explains that the
    FWS “shall provide to the Federal agency [e.g., Reclamation]
    . . . a written statement setting forth the Secretary’s opinion,
    and a summary of the information on which the opinion is
    based, detailing how the agency action affects the species or
    its critical habitat.” 
    16 U.S.C. § 1536
    (b)(3)(A) (emphasis
    added). “If jeopardy or adverse modification is found, the
    Secretary shall suggest those reasonable and prudent
    alternatives which he believes would not violated subsection
    (a)(2) of this section and can be taken by the Federal agency
    [e.g., Reclamation] . . . in implementing the agency action.”
    
    Id.
     (emphasis added). We would not ordinarily consider an
    “opinion” or “suggest[ion]” a “major Federal action[].” The
    regulations further provide that “[f]ollowing the issuance of
    a biological opinion, the Federal agency [e.g., Reclamation]
    shall determine whether and in what manner to proceed with
    the action in light of its section 7 obligations and the
    Service’s biological opinion.” 
    50 C.F.R. § 402.15
    (a). Our
    cases confirm that an action agency like Reclamation has
    some discretion to deviate from the BiOp and its RPAs. See
    Pyramid Lake Paiute Tribe of Indians v. U.S. Dep’t of Navy,
    
    898 F.2d 1410
    , 1418 (9th Cir. 1990) (“We have recognized
    that the Secretary is to be afforded some discretion in
    ascertaining how best to fulfill the mandate to conserve under
    section 7(a)(1) [of the ESA] . . . . For example, [an action]
    agency is given discretion to decide whether to implement
    SAN LUIS V. JEWELL                            129
    conservation recommendations put forth by the FWS.”);
    Tribal Vill. of Akutan v. Hodel, 
    869 F.2d 1185
    , 1193 (9th Cir.
    1988) (“The agency is not required to adopt the alternatives
    suggested in the biological opinion . . . . [The Secretary]
    satisfied section 7(a)(2) if he took alternative, reasonably
    adequate steps to insure the continued existence of any
    endangered or threatened species.”).
    We are mindful of the fact that “while the Service’s
    Biological Opinion theoretically serves an ‘advisory
    function,’ in reality it has a powerful coercive effect on the
    action agency.” Bennett v. Spear, 
    520 U.S. 154
    , 169 (1997)
    (citation omitted). “The action agency is technically free to
    disregard the Biological Opinion and proceed with its
    proposed action, but it does so at its own peril (and that of its
    employees), for ‘any person’ who knowingly ‘takes’ an
    endangered or threatened species is subject to substantial civil
    and criminal penalties, including imprisonment.” 
    Id. at 170
    .48
    But the “powerful coercive effect” of a BiOp on an action
    agency like Reclamation does not render it akin to the
    “[a]doption of formal plans” or “[a]pproval of specific
    projects,” which tend to trigger NEPA’s requirements.
    40 C.F.R. 1508.18(b)(2), (4). Unlike Reclamation, the FWS
    is not responsible for, and will not implement, the RPAs.
    And even if Reclamation felt compelled to implement the
    FWS’s proposal, we must bear in mind that Reclamation will
    48
    In Bennett, “The question for decision [was] whether the petitioners
    . . . [had] standing to seek judicial review of the biological opinion under
    the citizen-suit provision of the ESA . . . and the Administrative Procedure
    Act.” 
    Id. at 157
    . The case did not raise or resolve any questions
    concerning the application of NEPA to agency action under Section 7 of
    the ESA, which is at issue in this case.
    130                  SAN LUIS V. JEWELL
    complete an EIS evaluating the effects of implementing the
    BiOp. See infra section IV.B.2.
    The fact that Reclamation, and not the FWS, bears
    responsibility for implementing the BiOp—or an alternative
    that complies with Section 7’s mandate—distinguishes this
    case from Ramsey v. Kantor, 
    96 F.3d 343
     (9th Cir. 1996),
    where we held that the agency issuing a BiOp and ITS was
    required to comply with NEPA. In Ramsey, the National
    Marine Fisheries Service (NMFS) produced a BiOp and ITS
    in connection with the Columbia River Fish Management
    Plan, which is a “unique, judicially created, federal-state-
    tribal compact” that “apportions the fishing rights to the state
    and tribal members.” 
    Id. at 438
    . Notably, “The states then
    enact regulations governing fishing in the Columbia River,
    although they must do so in compliance with the terms of the
    Columbia River Fish Management Plan.” 
    Id.
     After the
    NMFS completed its BiOp and ITS, the states of Washington
    and Oregon issued regulations, which “would be illegal, if not
    for that [incidental take] statement,” permitting a specified
    amount of salmon fishing in the Columbia River. 
    Id. at 444
    .
    The Ramsey court “conclude[d] that the incidental take
    statement in this case is functionally equivalent to a permit.”
    
    Id.
     Our cases had already established that “if a federal permit
    is a prerequisite for a project with adverse impact on the
    environment, issuance of that permit does constitute major
    federal action and the federal agency involved must conduct
    an EA and possibly an EIS before granting it.” 
    Id.
     (citing
    Jones v. Gordon, 
    792 F.2d 821
    , 827–29 (9th Cir. 1986); Port
    of Astoria v. Hodel, 
    595 F.2d 467
    , 478–79 (9th Cir. 1979)).
    For this reason, the court held “that the issuance of [the
    incidental take] statement constitutes major federal action for
    purposes of NEPA.” Ramsey, 96 F.3d at 444.
    SAN LUIS V. JEWELL                    131
    In Ramsey, the states of Washington and Oregon occupied
    the position typically inhabited by a federal action agency
    like Reclamation because the BiOp and ITS were issued as
    part of a federal-state-tribal compact. Because NEPA applies
    only to “federal actions,” 
    42 U.S.C. § 4332
    (2)(C), in that case
    there was no downstream federal agency to complete an EIS.
    If the consulting agency, the NMFS, did not comply with the
    EIS requirement in Ramsey, then the action would have
    evaded NEPA review altogether even though the action was,
    in substance, identical to the process for issuing a permit,
    which would require the issuing agency to prepare an EIS.
    Here, there is no comparable need to require the FWS to
    prepare an EIS because Reclamation stands ready to do so.
    We have held that an agency need not complete an EIS where
    another agency will authorize or implement the action that
    triggers NEPA. In Sierra Club v. FERC, 
    754 F.2d 1506
     (9th
    Cir. 1985), the Federal Energy Regulatory Commission
    issued a preliminary permit to construct a hydroelectric
    power plant. 
    Id. at 1508
    . The plaintiffs argued that the
    Commission should have conducted an EIS before issuing the
    permit. 
    Id. at 1509
    . We disagreed, explaining that the
    applicants “can only enter federal land and conduct ground-
    breaking activities after obtaining Forest Service and BLM
    special use permits.        Thus, these agencies, not the
    Commission, will be responsible for evaluating the
    environmental impact of activities authorized by their special
    use permits.” Id.; see also Conner v. Burford, 
    848 F.2d 1441
    (9th Cir. 1988) (holding that the sale of particular oil and gas
    leases did not require the Forest Service to complete an EIS
    because “absent further governmental approval, the [ ] leases
    absolutely prohibit surface-disturbing activity.” (emphasis
    added)).
    132                 SAN LUIS V. JEWELL
    We see no reason to require a consulting agency like the
    FWS to complete an EIS when an action agency like
    Reclamation will either (1) prepare an EIS when it
    implements FWS’s proposal or (2) reject FWS’s proposal and
    prepare an EIS on whatever alternative it implements. We
    have condemned efforts to use NEPA as an “obstructionist
    tactic.” See Drakes Bay Oyster Co. v. Jewell, 
    729 F.3d 967
    ,
    984 (9th Cir. 2013); Douglas Cnty., 48 F.3d at 1508. Of
    course the fact that completing an EIS might be time
    consuming or costly does not excuse an agency from
    complying with NEPA; that is a balance struck by Congress,
    not the courts. But the statute requires completion of an EIS
    in connection with all “major Federal actions.” 
    42 U.S.C. § 4332
    (2)(C) (emphasis added). It does not require
    completion of an EIS by all agencies that make
    recommendations with respect to an action or participate in
    formulating a proposal for action. As the district court
    observed, “it makes little sense to have two agencies prepare
    separate NEPA documents for the same agency action.” San
    Luis & Delta-Mendota, 
    686 F. Supp. 2d at 1042
    .
    We hold that, under these circumstances, the FWS was
    not required to comply with NEPA in issuing the BiOp.
    There are situations where a consulting agency like the FWS
    is required to complete an EIS in conjunction with the
    preparation of a BiOp under Section 7 of the ESA. We have
    already identified one such scenario in Ramsey. But neither
    the statute nor our case law supports the proposition that the
    FWS’s production of a BiOp constitutes a “major Federal
    action[]” when its implementation is contingent on
    Reclamation’s adoption of the BiOp, which is an action that
    will trigger Reclamation’s obligation to complete an EIS.
    SAN LUIS V. JEWELL                              133
    2. Application of NEPA to Reclamation
    Having explained why the FWS was not required to
    produce an EIS when it issued the BiOp, we now address why
    the district court correctly concluded that Reclamation’s
    adoption and implementation of the BiOp requires the
    preparation of an EIS. The federal defendants do not contest
    the district court’s decision that Reclamation should have
    completed an EA and, if necessary, an EIS in conjunction
    with its implementation of the BiOp. But NRDC appeals the
    district court’s order granting summary judgment in favor of
    the plaintiffs on their claim that Reclamation violated
    NEPA.49
    49
    Because the federal defendants have not appealed the district court’s
    decision that Reclamation’s adoption of the BiOp is subject to NEPA, we
    must first confirm that NRDC has standing to challenge the decision. See
    Diamond v. Charles, 
    476 U.S. 54
    , 68 (1986) (“[A]n intervenor’s right to
    continue a suit in the absence of the party on whose side intervention was
    permitted is contingent upon a showing by the intervenor that he fulfills
    the requirements of Art. III.”).
    We hold that NRDC has standing to appeal the district court’s
    decision. “To determine whether an intervenor may appeal from a
    decision not being appealed by one of the parties in the district court, the
    test is whether the intervenor’s interests have been adversely affected by
    the judgment.” Didrickson v. U.S. Dep’t of the Interior, 
    982 F.2d 1332
    ,
    1338 (9th Cir. 1992). “To invoke this court’s jurisdiction on the basis of
    an injury related to the judgment, Intervenors must establish that the
    district court’s judgment causes their members a concrete and
    particularized injury that is actual or imminent and is likely to be redressed
    by a favorable decision.” W. Watersheds Project v. Kraayenbrink,
    
    632 F.3d 472
    , 482 (9th Cir. 2010). “[A] credible threat of harm is
    sufficient to constitute actual injury for standing purposes, whether or not
    a statutory violation has occurred.” Cent. Delta Water Agency v. United
    States, 
    306 F.3d 938
    , 950.
    134                     SAN LUIS V. JEWELL
    We begin by noting that we agree with the district court’s
    conclusion that Reclamation’s implementation of the BiOp is
    a “major Federal action[] significantly affecting the quality of
    the human environment,” even though NRDC does not
    directly challenge this portion of the court’s decision.
    
    42 U.S.C. § 4332
    (2)(C), First, implementation of the BiOp
    is a “major Federal action.” We have held “that where a
    proposed federal action would not change the status quo, an
    NRDC has demonstrated, for Article III standing purposes, that the
    district court’s judgment requiring Reclamation to complete an EIS poses
    “a credible threat of harm” to the delta smelt. The 2008 BiOp—which we
    hold today is not arbitrary and capricious—concluded that project
    operations jeopardized the delta smelt. There is, therefore, “a credible
    threat of harm” to the delta smelt if project operations continue. Although
    the district court remanded without vacatur, the plaintiffs can potentially
    use the judgment that Reclamation violated NEPA to enjoin
    implementation of the RPAs so long as doing so does not violate Section
    7 of the ESA. See In re Consolidated Delta Smelt Cases, 
    812 F. Supp. 2d 1133
    , 1198 (E.D. Cal. 2011) (judgment vacated by San Luis & Delta-
    Mendota Water Auth. v. Salazar, No. 11-17143 (9th Cir. Aug. 23, 2012))
    (“A court may not issue an injunction under NEPA that would cause a
    violation of other statutory requirements, such as those found in Section
    7 of the ESA. . . . However, where the evidence indicates that the ESA
    will not be violated by injunctive relief issued under NEPA, the presence
    of a NEPA claim permits consideration of economic harm evidence.”).
    The fact that a court cannot grant an injunction based on the judgment that
    Reclamation violated NEPA if doing so would cause a violation of Section
    7 of the ESA does not preclude NRDC from having standing to appeal the
    judgment because “a credible threat of harm is sufficient to constitute
    actual injury for standing purposes, whether or not a statutory violation
    has occurred.” Cent. Delta Water Agency, 
    306 F.3d at 950
     (emphasis
    added). The judgment thus introduces some probabilistic chance of
    environmental harm short of a statutory violation of Section 7 of ESA,
    which is sufficient for Article III standing. See 
    id. at 948
     (“‘Threatened
    environmental harm is by nature probabilistic.’” (quoting Friends of the
    Earth, Inc. v. Gaston Copper Recycling Corp., 
    204 F.3d 149
    , 160 (4th Cir.
    2000) (en banc)).
    SAN LUIS V. JEWELL                    135
    EIS is not necessary.” Upper Snake River Chapter of Trout
    Unlimited v. Hodel, 
    921 F.2d 232
    , 235 (9th Cir. 1990); see
    also Burbank Anti-Noise Group v. Goldschmidt, 
    623 F.2d 115
    , 116 (9th Cir. 1980) (“An EIS need not discuss the
    environmental effects of mere continued operation of a
    facility.”). In Upper Snake River, the court held that
    Reclamation’s decision to reduce the flow of water from a
    dam to 1,000 cfs was not a major federal action. Upper Snake
    River, 
    921 F.2d at 233
    . Reclamation had already set the flow
    rate below 1,000 cfs during 4.75% of the total days that the
    dam had been in operation, which led the court to conclude
    that “[w]hat they did in prior years and what they were doing
    during the period under consideration were no more than the
    routine managerial actions regularly carried on from the
    outset without change . . . they are doing nothing new, nor
    more extensive, nor other than that contemplated when the
    project was first operational.” 
    Id.
     at 234–35. The district
    court correctly distinguished Upper Snake River by observing
    that the BiOp does not merely involve a “routine” adjustment
    to the operation of the project. Rather, it “can be determined
    from the face of the BiOp and uncontroverted analyses of
    public data . . . [that] the Projects’ water delivery operations
    must be materially changed to restrict project water flows to
    protect the smelt.” San Luis & Delta-Mendota, 
    686 F. Supp. 2d at 1049
    .
    Second, Reclamation’s implementation of the BiOp
    “significantly affect[s] the human environment.” We have
    held that “[a]n agency is required to prepare an EIS where
    there are substantial questions about whether a project may
    cause significant degradation of the human environment.”
    Native Ecosystems Council v. U.S. Forest Serv., 
    428 F.3d 1233
    , 1239 (9th Cir. 2005) (emphasis in original). The
    district court correctly concluded that “dispositive
    136                 SAN LUIS V. JEWELL
    conclusions can be made without looking to the
    [administrative record].” San Luis & Delta-Mendota, 
    686 F. Supp. 2d at 1050
    . For example, the federal defendants’
    answer states that “Defendants aver that ‘reductions in
    exports from the Delta’ may ‘place greater demands upon
    alternative sources of water, including groundwater.’” 
    Id.
    The district court correctly concluded that Reclamation’s
    implementation of the BiOp is a “major Federal action[]
    significantly affecting the quality of the human environment.”
    
    42 U.S.C. § 4332
    (2)(C).
    NRDC’s argument on appeal is that, under these
    circumstances, NEPA conflicts with the ESA’s goal of
    preserving listed species like the delta smelt by imposing an
    additional procedural requirement on Reclamation. For this
    reason, NRDC contends that NEPA does not apply to
    Reclamation’s adoption and implementation of the BiOp,
    even if the action is a “major Federal action[] significantly
    affecting the quality of the human environment” that would
    ordinarily trigger NEPA review. We therefore consider
    whether we should set aside the EIS requirement when an
    agency implements a BiOp and RPAs designed to ensure that
    its action “is not likely to jeopardize the continued existence
    of any endangered species or threatened species or result in
    the destruction or adverse modification of habitat of such
    species.” 
    16 U.S.C. § 1536
    (a)(2). We find no basis in the
    statute or our case law for excusing Reclamation from its
    NEPA obligations under these circumstances.
    On its face, the statute does not permit case-by-case
    exceptions that assess how NEPA interacts with the
    substantive statute at issue. It simply requires that “to the
    fullest extent possible . . . all agencies of the Federal
    Government shall” complete an EA and, if necessary, an EIS
    SAN LUIS V. JEWELL                    137
    for all “major Federal actions significantly affecting the
    quality of the human environment.” 
    42 U.S.C. § 4332
    (2)(C).
    Congress has expressly provided that NEPA does not apply
    to certain statutory schemes. For example, “No action taken
    under the Clean Air Act shall be deemed a major Federal
    action significantly affecting the quality of the human
    environment within the meaning of the National
    Environmental Policy Act of 1969.” 
    15 U.S.C. § 793
    (c)(1).
    In other words, no action taken under the Clean Air Act will
    trigger NEPA’s requirement that the agency produce an EIS.
    See also 
    42 U.S.C. § 8473
     (stating that the EIS requirement
    does not apply to certain exemptions for electric
    powerplants); 
    42 U.S.C. § 5159
     (providing that actions
    restoring particular facilities to their condition prior to a
    disaster or emergency are exempt from the EIS requirement).
    Most notably, Section 7 of the ESA—the provision at issue
    here—carves out a narrow exception to the EIS requirement.
    The ESA authorizes the formation of an “Endangered Species
    Committee” that is empowered to grant exemptions from the
    general prohibition on agency actions that “jeopardize the
    continued existence” of listed species or “result in the
    destruction or adverse modification of [their] habitat.”
    
    16 U.S.C. § 1536
    (e). The statute specifically provides that a
    decision by the Endangered Species Committee to exempt an
    agency action from the ESA’s prohibitions is not subject to
    NEPA if the agency already completed an EIS concerning the
    effects of the action. 
    Id.
     at § 1536(k).
    This could very well be the end of our inquiry. Congress
    has repeatedly demonstrated that it knows how to exempt
    particular substantive statutes from the EIS requirement when
    it wishes to do so. Moreover, Congress has expressly
    exempted a particular subset of actions under Section 7 of the
    ESA—decisions by the Endangered Species Committee
    138                 SAN LUIS V. JEWELL
    where an EIS was already completed by the action agency.
    But Congress did not exempt all efforts to avoid jeopardizing
    the survival of a listed species from the EIS requirement. In
    fact, Congress’s decision to exempt certain decisions by the
    Endangered Species Committee from the EIS requirement
    reaffirms that NEPA applies to other actions under Section 7
    of the ESA, including Reclamation’s implementation of the
    BiOp.
    There is additional statutory evidence that Reclamation’s
    adoption and implementation of the BiOp triggers its
    obligations under NEPA. Section 7 of the ESA provides that
    a biological assessment “may be undertaken as part of a
    Federal agency’s compliance with the requirements of section
    102 of the National Environmental Policy Act of 1969
    (
    42 U.S.C. § 4332
    ),” which is the section that governs the
    preparation of an EIS. 
    16 U.S.C. § 1536
    (c)(1). This is
    evidence that Congress specifically contemplated that an
    action agency discharging its duties under Section 7 of the
    ESA would also comply with NEPA by completing an EA
    and, if necessary, an EIS. The regulations also acknowledge
    that the agencies are expected to concurrently comply with
    both Section 7 of the ESA and NEPA. See 
    50 C.F.R. § 402.06
     (“Consultation, conference, and biological
    assessment procedures under section 7 may be consolidated
    with interagency cooperation procedures required by other
    statutes, such as the National Environmental Policy Act
    (NEPA).”).
    NRDC does not cite a single case where any court has
    held that an action agency’s obligations under Section 7 of
    the ESA excuse it from complying with NEPA. There are,
    however, a number of cases holding that other substantive
    statutes are exempt from the EIS requirement, even though
    SAN LUIS V. JEWELL                    139
    Congress has not expressly provided an exemption. NRDC
    would have us extend the rationale of those cases to these
    circumstances.
    We have recognized two circumstances where an agency
    need not complete an EIS despite an absence of an express
    statutory exemption. First, an agency is excused from
    complying with NEPA where doing so “would create an
    irreconcilable and fundamental conflict” with the substantive
    statute at issue. Flint Ridge Dev. Co. v. Scenic Rivers Ass’n
    of Okla., 
    426 U.S. 776
    , 788 (1976). Second, we have
    identified a limited number of instances where a substantive
    statute has “displaced” NEPA’s requirements, even though
    there is not “an irreconcilable” conflict between the
    substantive statute and the EIS requirement. See Douglas
    Cnty., 48 F.3d at 1502 (“[The plaintiff] argues that without
    this ‘irreconcilable’ statutory conflict NEPA must apply. We
    disagree, and . . . we hold that NEPA does not apply to the
    designation of a critical habitat.”).
    First, in Flint Ridge the Supreme Court held that the EIS
    requirement did not apply because requiring the agency to
    prepare an EIS “would create an irreconcilable and
    fundamental conflict with the Secretary’s duties under the
    [substantive statute at issue].” Flint Ridge, 
    426 U.S. at 788
    .
    There, the substantive statute provided that a document filed
    with the agency would automatically become effective in
    thirty days under certain circumstances. 
    Id. at 788
    . The
    Court explained that “[i]t is inconceivable that an
    environmental impact statement could, in 30 days, be drafted,
    circulated, commented upon, and then reviewed and revised
    in light of the comments.” 
    Id. at 789
    . But in Jones v.
    Gordon, 
    792 F.2d 821
     (9th Cir. 1986), we observed that
    “Flint Ridge applies only when a conflict is ‘clear and
    140                  SAN LUIS V. JEWELL
    unavoidable’ and ‘irreconcilable and fundamental.’” 
    Id. at 826
    . The Jones court explained that, unlike in Flint Ridge,
    the agency “could withhold publication long enough to
    comply with any NEPA requirement for preparation of an
    environmental impact statement.” 
    Id.
    There is no “irreconcilable and fundamental conflict”
    between NEPA and Section 7 of the ESA. Although the
    statute sets out a timetable for the consultation process, it is
    flexible enough to accommodate the preparation of an EIS.
    See 
    16 U.S.C. § 1536
    (b)(1)(A) (“Consultation under
    subsection (a)(2) of this section with respect to any agency
    action shall be concluded within the 90-day period beginning
    on the date on which initiated or, subject to paragraph (B),
    within such other period of time as is mutually agreeable to
    the Secretary and federal agency.” (emphasis added));
    
    16 U.S.C. § 1536
    (b)(1)(B) (“The Secretary and the Federal
    agency may mutually agree to extend a consultation period
    established under the preceding sentence if the Secretary,
    before the close of such period, obtains the consent of the
    application to the extension.”); see also Westlands Water
    Dist. v. United States Dep’t of Interior, 
    850 F. Supp. 1388
    ,
    1423 (E.D. Cal. 1994) (“Section 7 of the ESA gives agencies
    control over the time within which consultation is to be
    concluded . . . . [And] ESA § 7 provides for the inclusion of
    ‘applicants’ within the consultation process, which
    demonstrates access to the ESA process by interested parties
    . . . . Neither timing nor secrecy concerns bar the ability to
    comply with NEPA.”).
    Second, we have held that an agency action might be
    exempt from NEPA even “without this ‘irreconcilable’
    statutory conflict” identified in Flint Ridge. Douglas Cnty.,
    48 F.3d at 1502; see also Drakes Bay Oyster, 729 F.3d at 984;
    SAN LUIS V. JEWELL                           141
    Merrell, 807 F.2d at 778. In Douglas County, we held that
    the Secretary of the Interior need not complete an EIS when
    designating the critical habitat of a listed species pursuant to
    Section 4 of the ESA. Douglas Cnty., 48 F.3d at 1507.50 The
    Douglas County court concluded that “Congress intended to
    displace” NEPA’s procedures when authorizing the agency to
    designate critical habitat under Section 4 of the ESA. Id. at
    1504 n.10. But none of the factors relied on by the Douglas
    County court in reaching this decision apply with the same
    force where, as here, the agency action at issue is the
    implementation of a BiOp under Section 7 of the ESA.
    The Douglas County court reasoned that the process for
    designating critical habitat under Section 4 of the ESA
    effectively accomplished all of NEPA’s goals without
    requiring an EIS, thereby “mak[ing] the NEPA procedure
    seem ‘superfluous.’” Id. at 1503. Section 4 of the ESA
    compels “the Secretary [to] consider impacts that concern
    NEPA, to the extent that the critical habitat designation has
    a positive environmental effect on the species in question.”
    Id. Furthermore, “The critical designation process also
    provides for public notice, another goal of NEPA.” Id.
    But the same cannot be said for Section 7 of the ESA,
    which is at issue in this case. In Save the Yaak Committee v.
    Block, 
    840 F.2d 714
     (9th Cir. 1988), we explained the
    difference between a biological assessment (BA) produced
    50
    The Tenth Circuit subsequently disagreed with the result that we
    reached in Douglas County, creating a circuit split concerning whether
    NEPA applies to the designation of critical habitat under Section 4 of the
    ESA. See Catron Cnty. Bd. of Comm’rs v. U.S. Fish & Wildlife Serv.,
    
    75 F.3d 1429
    , 1436 (10th Cir. 1996); see also Cape Hatteras Access Pres.
    Alliance v. U.S. Dep’t of Interior, 
    344 F. Supp. 2d 108
    , 133–36 (D.D.C.
    2004).
    142                  SAN LUIS V. JEWELL
    pursuant to Section 7 of the ESA, and an EA or EIS prepared
    in accordance with NEPA. The Save the Yaak court
    considered an argument that “even if the EA was inadequate,
    it was supplemented by the biological assessment (BA)”
    completed under Section 7 of the ESA. Id. at 718. We
    rejected this reasoning, explaining that “[w]hile a BA
    analyzes the impact of a proposed action upon endangered
    species, an EA analyzes the impact of the proposed action on
    all facets of the environment. Thus, if only a BA is prepared
    there may be gaps in the agency’s environmental analysis.”
    Id.
    Courts have offered several other examples of the
    differences between the Section 7 process and the one
    prescribed by NEPA. For instance, “the ESA’s Section 7
    consultation process fails to provide for public comment in
    the same way that NEPA does.” Fund for Animals v. Hall,
    
    448 F. Supp. 2d 127
    , 136 (D.D.C. 2006). This is particularly
    important because “[p]ublication of an EIS, both in draft and
    final form, also serves a larger informational role. It gives the
    public the assurance that the agency ‘has indeed considered
    environmental concerns in the decisionmaking process,’ and,
    perhaps more significantly, provides a springboard for public
    comment.” Robertson v. Methow Valley Citizens Council,
    
    490 U.S. 332
    , 350 (1989) (quoting Baltimore Gas & Elec.
    Co., 
    462 U.S. at 97
    ) (internal citation omitted). Additionally,
    “the ESA only requires agencies to consider the cumulative
    impacts of non-federal actions, while NEPA requires agencies
    to consider the cumulative impacts of all actions.” Fund for
    Animals, 
    448 F. Supp. 2d at 136
    ; see also 
    50 C.F.R. § 402.02
    (describing the cumulative effects analysis under the ESA);
    
    40 C.F.R. § 1508.7
     (describing the cumulative impacts
    analysis under NEPA). We cannot say that Section 7 of the
    ESA renders NEPA “superfluous” when the statutes evaluate
    SAN LUIS V. JEWELL                   143
    different types of environmental impacts through processes
    that involve varying degrees of public participation.
    In Merrell, we held that the EIS requirement does not
    apply to FIFRA’s scheme for registering pesticides because
    the two processes are markedly different. See Merrell,
    807 F.2d at 778 (“The differences between FIFRA’s
    registration procedure and NEPA’s requirements indicate that
    Congress did not intend NEPA to apply.”). Although both
    Merrell and Douglas County conclude that NEPA does not
    apply to a particular substantive statute, they do so for
    opposite reasons. Douglas County holds that Section 4 of the
    ESA renders NEPA superfluous because the processes are
    sufficiently similar, while Merrell holds that FIFRA renders
    NEPA superfluous because the processes are sufficiently
    different. See Douglas Cnty., 48 F.3d at 1503 (“[T]he
    Secretary will consider impacts that concern NEPA, to the
    extent that the critical habitat designation has a positive
    environmental effect on the species in question. The critical
    designation process also provides for public notice, another
    goal of NEPA.”); Merrell, 807 F.2d at 779 (“[W]hen
    Congress revised FIFRA in 1972, it designed a registration
    procedure with public notice and public participation
    provisions that differ materially from those that NEPA would
    require.”).
    Although we have already acknowledged the differences
    between Section 7 of the ESA and NEPA, we do not think
    that the distinctions are as pronounced as those in Merrell,
    where the court concluded that “[t]o apply NEPA to FIFRA’s
    registration process would sabotage the delicate machinery
    that Congress designed to register new pesticides.” Merrell,
    807 F.2d at 779. As we have observed, Congress specifically
    contemplated that an agency could comply with NEPA while
    144                      SAN LUIS V. JEWELL
    discharging its duties under Section 7 of the ESA. See
    
    16 U.S.C. § 1536
    (c)(1) (explaining that the biological
    assessment required by Section 7 of the ESA “may be
    undertaken as part of a Federal agency’s compliance with the
    requirements of section 102 of the National Environmental
    Policy Act of 1969 (
    42 U.S.C. § 4332
    )”). In this very case,
    the federal agencies acknowledge that Reclamation will
    complete an EIS in conjunction with its adoption and
    implementation of the BiOp, which undercuts the notion that
    the two processes are incompatible.           Under these
    circumstances, we cannot conclude that the process set out by
    Section 7 of the ESA clashes with NEPA to such an extent
    that requiring Reclamation to produce an EIS “would
    sabotage the delicate machinery that Congress designed.”
    Merrell, 807 F.2d at 779. Instead, we find that Section 7 of
    the ESA fits within the broad swath of statutes that coexist
    with NEPA.51
    51
    A number of other circuits have held that an agency need not produce
    an EIS where the substantive statute at issue offers a procedure that is the
    “functional equivalent” of the EIS process. See, e.g., State of Ala. ex rel.
    Siegleman v. EPA, 
    911 F.2d 499
    , 504 (11th Cir. 1990); Limerick
    Ecological Action, Inc. v. U.S. Nuclear Regulatory Comm’n., 
    869 F.2d 719
    , 729 n.7 (3d Cir. 1989); Izaak Walton League of Am. v. Marsh,
    
    655 F.2d 346
    , 367 n.51 (D.C. Cir. 1981).
    We have been skeptical of the “functional equivalent” approach and
    have not used this language in our cases. See Douglas Cnty., 48 F.3d at
    1504 n.10 (“Courts have used a ‘functional equivalent’ test to exempt
    agency action from NEPA requirements . . . . The defendants here do not
    advance the functional equivalent argument, so we do not address it. The
    [plaintiff] would have us believe that the ‘displacement’ argument
    defendants make is the same as the ‘functional equivalent’ test. We do not
    agree. The ‘displacement’ argument asserts that Congress intended to
    displace one procedure with another. The ‘functional equivalent’
    argument is that one process requires the same steps as another.”);
    Merrell, 807 F.2d at 781 (“While we hesitate to adopt the ‘functional
    SAN LUIS V. JEWELL                            145
    The Douglas County court also noted that Congress
    acquiesced to decisions by the agencies and courts that
    compliance with NEPA was not required when designating
    critical under habitat Section 4 of the ESA. We noted that in
    1983 the Secretary of the Interior stopped preparing EAs and
    EISs before designating critical habitat, yet Congress did not
    address the agency’s interpretation of the statute when it
    amended the ESA in 1988. Douglas Cnty., 48 F.3d at 1504.
    The Sixth Circuit had also suggested in dicta that it might not
    be necessary to prepare an EIS before designating critical
    habitat before the 1988 amendments to the ESA. Id. (citing
    Pac. Legal Found. v. Andrus, 
    657 F.2d 829
    , 835 (6th Cir.
    1981)). But here, neither the agencies nor the courts have
    interpreted Section 7 of the ESA to permit noncompliance
    with NEPA. As noted, the relevant regulations indicate that
    the action agency will complete an EIS while carrying out its
    duties under Section 7, and the federal defendants in this case
    have assumed that Reclamation will complete an EIS
    evaluating the effects of implementing the BiOp. See
    
    50 C.F.R. § 402.06
     (“Consultation, conference, and biological
    assessment procedures under section 7 may be consolidated
    equivalence’ rationale, we are confident that Congress did not intend
    NEPA to apply to FIFRA registrations.”).
    NRDC relies on Douglas County and Merrell, which are
    “displacement” cases rather than “functional equivalent” cases. To our
    knowledge, none of the circuits that have adopted the “functional
    equivalent” test have held that the procedures set out by Section 7 of the
    ESA are equivalent to the EIS requirement. Although NRDC does not
    urge us to adopt the “functional equivalent” approach, we note that the
    factors considered in the preceding paragraphs are the same ones that we
    would address under that analysis. Regardless of the language used to
    conduct the analysis, the statutes and regulations reveal that Section 7 of
    the ESA and NEPA involve different processes that measure different
    kinds of environmental impacts.
    146                  SAN LUIS V. JEWELL
    with interagency cooperation procedures required by other
    statutes, such as the National Environmental Policy Act
    (NEPA).”). And, to our knowledge, there are no cases stating
    that an agency need not comply with NEPA because of its
    obligations under Section 7 of the ESA.
    Next, the Douglas County court stated that there is no
    reason to prepare an EIS “when the action at issue does not
    alter the natural, untouched physical environment at all.”
    Douglas Cnty., 48 F.3d at 1505. We explained that “the
    purpose of NEPA is to protect the physical environment, and
    the purpose of preparing an EIS is to alert agencies and the
    public to potential adverse consequences to the land, sea or
    air.” Id. Therefore, the designation of critical habitat, which
    results in the land at issue being left alone, does not require
    an EIS. Here, the BiOp does far more than leave nature
    alone. Humans have dramatically altered the Bay-Delta
    ecosystem. Even if we assume that implementing the BiOp
    is a step toward returning the ecosystem to its natural state,
    there is no doubt that project operations will continue to alter
    the physical environment, albeit in different ways. We have
    already interpreted this portion of Douglas County quite
    narrowly. See Kootenai Tribe of Idaho v. Veneman, 
    313 F.3d 1094
     (9th Cir. 2002) (abrogated on other grounds by
    Wilderness Soc’y v. U.S. Forest Serv., 
    630 F.3d 1173
     (9th
    Cir. 2011)). In Kootenai Tribe, the agency announced a
    “Roadless Rule” that prohibited construction of new roads in
    certain areas. Kootenai Tribe, 313 F.3d at 1105. We
    considered an argument that NEPA should not apply to the
    agency’s action in light of the Douglas County court’s
    statement that “an EIS is not required to leave nature alone.”
    Id. at 1114 (quoting Douglas Cnty., 48 F.3d at 1505). We
    held that “[b]ecause human intervention, in the form of forest
    management, has been part of the fabric of our national
    SAN LUIS V. JEWELL                           147
    forests for so long, we conclude that, in the context of this
    unusual case, the reduction in human intervention that would
    result from the Roadless Rule actually does alter the
    environmental status quo . . . . The Forest Service’s Roadless
    initiative thus required an EIS under NEPA.” Id. at 1115. An
    action to lessen one form of pressure on the natural
    environment, such as Reclamation’s implementation of the
    BiOp, is distinguishable from a decision to continue to leave
    a portion of nature untouched altogether.
    At its broadest point, our opinion in Douglas County
    implied that the agency’s designation of critical habitat did
    not trigger NEPA review because it was an environmental
    preservation effort. We explained that “[b]y designating
    critical habitats for endangered or threatened species, the
    Secretary ‘is working to preserve the environment and
    prevent the irretrievable loss of a natural resource.’ Thus the
    action of the Secretary in designating a critical habitat
    furthers the purpose of NEPA. Requiring the EPA to file an
    EIS ‘would only hinder its efforts at attaining the goal of
    improving the environment.’” Douglas Cnty., 48 F.3d at
    1506. We recently applied this principle in Drakes Bay
    Oyster, where we wrote that “[t]he Secretary’s decision is
    essentially an environmental conservation effort, which has
    not triggered NEPA in the past.” Drakes Bay Oyster,
    729 F.3d at 984 (citing Douglas Cnty., 48 F.3d at 1505–06).
    We do not read either Douglas County or Drakes Bay
    Oyster to stand for the proposition that efforts to preserve the
    natural environment are per se exempt from NEPA.52 As
    52
    We recently observed that our court has yet to hold that an agency that
    has already produced an EA need not produce an EIS when the action in
    question will only have beneficial impacts on the environment. See
    148                     SAN LUIS V. JEWELL
    noted, the Douglas County court relied on the observation
    that designating critical habitat under Section 4 of the ESA is
    an “action[] that do[es] nothing to alter the natural physical
    environment.” Douglas Cnty., 48 F.3d at 1505. Similarly, in
    Drakes Bay Oyster, the only purported “adverse
    environmental consequences” of designating the area in
    question as a wilderness were “short-term harms, such as
    noise associated with heavy machinery needed to remove
    Drakes Bay’s structures” in order to return the area to its
    natural state. Drakes Bay Oyster, 729 F.3d at 984. We noted
    that “such relatively minor harms do not by themselves
    ‘significantly affect[]’ the environment in such a way as to
    Humane Soc’y of U.S. v. Locke, 
    626 F.3d 1040
    , 1056 (9th Cir. 2010) (“As
    a threshold matter, plaintiffs’ argument appears to raise an issue of first
    impression in this circuit: whether NEPA requires an agency to prepare an
    EIS when an action has a significant beneficial impact but not significant
    adverse impact on the environment.”); see also 
    id. at 1046
     (“[T]o comply
    with NEPA, NMFS prepared an environmental assessment . . . . The final
    environmental assessment resulted in a finding of no significant impact
    under NEPA.”). In Humane Society, we did not resolve the question
    whether an agency that has produced an EA showing significant beneficial
    environmental impacts and no adverse environmental impacts must still
    complete an EIS. See 
    id. at 1056
    .
    In order to hold that Reclamation need not comply with NEPA, we
    would need to take two substantial steps forward because, in this case,
    Reclamation did not even complete an EA. We see no basis for holding
    that an agency can avoid NEPA review altogether when it believes that an
    agency action will have beneficial impacts on the environment when we
    have not even excused an agency from producing an EIS when its EA
    shows that its action will have exclusively beneficial impacts on the
    environment. In other words, even if we had some basis for assuming that
    Reclamation’s implementation of the BiOp would have exclusively
    beneficial impacts on the environment, we would still lack a firm
    foundation for holding that Reclamation need not prepare an EA and, if
    necessary, an EIS.
    SAN LUIS V. JEWELL                    149
    implicate NEPA.” 
    Id.
     But here, NRDC does not even contest
    the district court’s conclusion that implementation of the
    BiOp “significantly affect[s] the human environment.” See
    San Luis & Delta-Mendota, 
    686 F. Supp. 2d at 1050
    .
    Whatever effects implementing the BiOp might have on the
    human environment, it is apparent that they are more complex
    and wide-ranging than the removal of a few buildings in
    Drakes Bay Oyster.
    At this point, we can only speculate about what kind of
    significant effects will eventually result from implementation
    of the BiOp because Reclamation has not yet completed its
    EIS.     But it is beyond dispute that Reclamation’s
    implementation of the BiOp has important effects on human
    interaction with the natural environment. We know that
    millions of people and vast areas of some of America’s most
    productive farmland will be impacted by Reclamation’s
    actions. Those impacts were not the focus of the BiOp. In
    sum, we cannot reach an informed decision about the extent
    to which implementation of the BiOp is an environmental
    preservation action in the vein of Douglas County and Drakes
    Bay Oyster because we do not know how the action will
    impact the broader natural environment. We find no basis for
    exempting Reclamation from the EIS requirement. See
    Methow Valley Citizens Council, 490 U.S. at 349 (“NEPA
    ensures that important effects will not be overlooked or
    underestimated only to be discovered after resources have
    been committed or the die otherwise cast.”). We recognize
    that the preparation of an EIS will not alter Reclamation’s
    obligations under the ESA. But the EIS may well inform
    Reclamation of the overall costs—including the human
    costs—of furthering the ESA. So informed, Reclamation has
    150                     SAN LUIS V. JEWELL
    the option of seeking an exemption from the ESA from the
    Endangered Species Committee. See 
    16 U.S.C. § 1536
    (e).53
    Finally, NRDC argues that Reclamation’s issuance of the
    2004 OCAP is the “major Federal action[]” that should have
    been subject to NEPA review instead of its implementation
    53
    The Endangered Species Committee is the exclusive avenue through
    which an applicant may obtain an exemption from the ESA’s substantive
    prohibitions. See 
    16 U.S.C. §1536
    (a)(2) (“Each federal agency shall . . .
    insure that any action authorized, funded, or carried out by such agency
    . . . is not likely to jeopardize the continued existence of any endangered
    species or threatened species or result in the destruction or adverse
    modification of habitat of such species . . . unless such agency has been
    granted an exemption for such action by the Committee pursuant to
    [
    16 U.S.C. § 1536
    (h)].”); see also Portland Audubon Soc’y v. Endangered
    Species Comm., 
    984 F.2d 1534
    , 1537 (9th Cir. 1993) (“The Committee
    was created by the Endangered Species Act for the sole purpose of making
    final decisions on applications for exemptions from the Act . . . . Because
    it is the ultimate arbiter of the fate of an endangered species, the
    Committee is known as “The God Squad.”). The Committee has only
    convened on a handful of occasions and has only granted two exemptions.
    See Portland Audubon Soc’y, 
    984 F.2d at 1537
    . Commentators have
    discussed whether action from the Committee would be appropriate under
    these circumstances. See generally Eric M. Yuknis, Note, Would a “God
    Squad” Exemption under the Endangered Species Act Solve the California
    Water Crisis?, 
    38 B.C. Envtl. Aff. L. Rev. 567
     (2011).
    For our purposes, it is worth noting that the possibility of review by
    the Endangered Species Committee, however unlikely it may be, renders
    the preparation of an EIS more than a mere academic exercise in cases
    involving Section 7 of the ESA. Although the agency cannot ignore its
    obligations under the ESA because of the impacts on other aspects of the
    human environment, the Committee might wish to consider these factors
    in making an exemption decision. And, as previously noted, the statute
    contemplates that the agency will have completed an EIS by providing
    that the Committee itself need not do so if the agency has already prepared
    an EIS with respect to the action subject to the Committee’s review. See
    
    16 U.S.C. § 1536
    (k).
    SAN LUIS V. JEWELL                     151
    of the 2008 BiOp. In a different case, NRDC alleged that
    Reclamation’s “approval and implementation” of the 2004
    OCAP triggered its obligation to complete an EIS. See Pac.
    Coast Fed’n of Fishermen’s Ass’n/Inst. for Fisheries Res. v.
    Gutierrez, No. 1:06-cv-00245, 
    2007 WL 1752289
    , at *4 (E.D.
    Cal. June 15, 2007). In Gutierrez, the district court held that
    the 2004 OCAP was not subject to NEPA because its was not
    a “final agency action.” See 
    id.
     at *12–13 (“[The OCAP]
    do[es] not implement any actions or inactions. They are
    informational. If any proposed changes are initiated that will
    have the requisite effect on the environment, such changes
    will be agency action subject to NEPA review. The purpose
    of the OCAP is ‘to serve as a baseline description of the
    facilities and operating environment of the CVP and SWP.’”).
    NRDC contends that Gutierrez was wrongly decided and
    that the district court should have required Reclamation to
    complete an EIS on the 2004 OCAP. Yet NRDC and the
    other plaintiffs in Gutierrez did not appeal the district court’s
    decision concerning its NEPA claims. Not only is NRDC
    collaterally estopped from relitigating the decision in
    Gutierrez, but the issue is also not pertinent to our holding
    that Reclamation’s implementation of the BiOp requires the
    agency to prepare an EIS.             Even if Reclamation’s
    implementation of the 2004 OCAP was a final decision that
    changed the status quo of the project operations in a way that
    significantly affected the environment, that does not mean
    that Reclamation’s implementation of the 2008 BiOp did not
    also change the status quo in a way that significantly alters
    the environment, thereby requiring an additional EIS.
    NRDC bolsters its contention that NEPA should apply to
    the 2004 OCAP in lieu of the 2008 BiOp by referencing
    Section 7 of the ESA and its regulations. As noted above, the
    152                  SAN LUIS V. JEWELL
    statute and its regulations explain that an action agency like
    Reclamation can coordinate the preparation of its biological
    assessment with its obligations under NEPA. See 
    16 U.S.C. § 1536
    (c)(1); 
    50 C.F.R. § 402.06
    . NRDC reasons that these
    provisions suggest that NEPA review of the BiOp is not
    required because Reclamation could not complete its EIS
    until after its Section 7 consultation with the FWS rather than
    at the same time as its consultation obligations. But even if
    we fully credit this line of reasoning, it does not affect our
    conclusion that NEPA applies to Reclamation’s
    implementation of the BiOp. We need not locate affirmative
    and unequivocal confirmation in every substantive statute that
    a particular agency action requires NEPA review; most
    substantive statutes never mention NEPA at all. They do not
    need to because NEPA itself provides that “to the fullest
    extent possible . . . all agencies of the Federal Government
    shall” complete an EA and, if necessary, an EIS for all “major
    Federal actions significantly affecting the quality of the
    human environment.” 
    42 U.S.C. § 4332
    (2)(C). The fact that
    Section 7 of the ESA expressly mentions the EIS requirement
    supports, rather than rebuts, the notion that NEPA applies to
    the action at issue here.
    Our starting point was that NEPA applies to
    Reclamation’s implementation of the BiOp because it is a
    “major Federal action[] significantly affecting the quality of
    the human environment.” We acknowledge that we have
    previously held that the EIS requirement does not apply to
    particular agency actions even in the absence of an express
    statutory exemption. See Drakes Bay Oyster, 729 F.3d at 984;
    Douglas Cnty., 48 F.3d at 1507; Merrell, 807 F.2d at 781.
    But the factors identified in those cases are simply not present
    here. We are cognizant of our commitment to avoid
    “mak[ing] NEPA more of an ‘obstructionist tactic’ to prevent
    SAN LUIS V. JEWELL                   153
    environmental protection than it may already have become.”
    Douglas Cnty., 48 F.3d at 1508; see also Drakes Bay Oyster,
    729 F.3d at 984. But, as noted, the district court remanded
    the BiOp and RPAs without vacatur, and it continues to
    actively manage Reclamation’s deadline for completing the
    EIS process. We conclude that Reclamation is obligated to
    comply with NEPA, and we affirm the judgment of the
    district court with respect to the NEPA claims.
    VI. CONCLUSION
    For the forgoing reasons, the judgment of the district
    court is reversed in part and affirmed in part. The matter is
    remanded to the district court for further proceedings
    consistent with this opinion. Each party shall bear its own
    costs on appeal.
    REVERSED IN PART AND AFFIRMED IN PART.
    154           SAN LUIS V. JEWELL
    GLOSSARY OF TERMS
    APA          Administrative Procedure Act
    BA           Biological Assessment
    Bay-Delta    San Francisco Bay and Sacramento-San
    Joaquin Delta
    BiOp         2008 biological opinion
    CALFED       CALFED Bay-Delta Program
    cfs          cubic feet per second
    CVP          Central Valley Project
    CVPIA        Central Valley Project Improvement Act
    DWR          California   Department      of       Water
    Resources
    EIS          Environmental Impact Statement
    ESA          Endangered Species Act
    FCRPS        Federal Columbia River Power System
    FIFRA        Federal Insecticide, Fungicide, and
    Rodenticide Act
    FMWT         Fall Midwater Trawl index
    FWS          U.S. Fish and Wildlife Service
    SAN LUIS V. JEWELL                    155
    ITS                incidental take statement
    NMFS               National Marine Fisheries Service
    NEPA               National Environmental Protection Act
    OCAP               2004 Operating Criteria and Plan
    OMR                Old and Middle Rivers
    RPA                reasonable and prudent alternatives
    Reclamation        U.S. Bureau of Reclamation
    SWP                State Water Project
    ARNOLD, Circuit Judge, concurring in part and dissenting in
    part:
    I respectfully dissent from Parts III, IV.A, IV.B, IV.E, and
    V.B of the court’s opinion and concur in the rest of it. I
    address the issue dealt with in Part III as it arises in
    considering the merits of the challenges to the BiOp.
    1. I do not believe that the district court erred in holding
    that the BiOp’s OMR flow limits were set arbitrarily and
    capriciously. First of all, I discern no error in admitting a
    portion of the declaration from Dr. Richard Deriso, who holds
    advanced degrees in mathematics and biomathematics,
    discussing the use of raw salvage data to justify the flow
    prescription. A decision to include evidence that is outside
    the administrative record is reviewed for abuse of discretion,
    156                  SAN LUIS V. JEWELL
    see Lands Council, 
    395 F.3d at
    1030 n.11, and admitting this
    evidence fell within one of the narrow exceptions to the
    general rule against extra-record evidence, because it was
    necessary to explain technical terms or complex subject
    matter, see Nw. Envtl. Advocates v. Nat’l Marine Fisheries
    Serv., 
    460 F.3d 1125
    , 1145 (9th Cir. 2006). Furthermore, Dr.
    Deriso’s declarations were consistent with advice offered by
    independent peer reviewers and draft notes of a delta smelt
    evaluation team at FWS assembled before the final BiOp
    issued, and with the testimony of Rule 706 experts Dr. Punt
    and Dr. Quinn, who recognized Dr. Deriso’s declarations and
    stated that the validity of the flow regimes specified in the
    BiOp was undermined by its incomplete analysis. Nor was
    there any “battle of the experts” here, as the court maintains,
    because the responses to Dr. Deriso’s declarations from
    FWS’s mathematical statistician, Dr. Ken Newman, were
    mostly vague, and he generally agreed with Dr. Deriso that
    salvage should be scaled by some measure of population
    abundance.
    As for the merits of this issue, Appellants do not contend
    that the use of raw salvage data was scientifically acceptable;
    they maintain instead that the flow prescription also relied on
    and was supported by other information. Based on my
    review of this information, however, the BiOp did not
    connect it to flow limits at all, or there was no explanation for
    why it yielded the flow prescription that the BiOp specified.
    As to FWS’s use of normalized data in the ITS, I am not
    convinced that this is relevant to whether it was scientifically
    sound for FWS to use only raw salvage data to set the flow
    prescription. While certain DWR comments support the flow
    prescription, the parties do not dispute that these comments
    arose from the district court’s previous remedial imposition
    of such a prescription, which, as the district court noted,
    SAN LUIS V. JEWELL                    157
    occurred before the court became aware that using raw
    salvage data was not accepted scientific methodology.
    Because FWS based its flow prescription solely on the
    unexplained use of raw salvage data, I believe that its
    expertise in methodological matters is not entitled to
    deference, since that use was not rationally connected to the
    best available science, see W. Watersheds Project v.
    Kraayenbrink, 
    632 F.3d 472
    , 493 (9th Cir. 2011); and
    because FWS did not consider all relevant factors or
    articulate a rational connection between the facts found and
    the choices made, I agree with the district court that its
    determination as to the flow prescription was arbitrary and
    capricious, see 
    id. at 496
    .
    2. I also concur in the district court’s conclusion that the
    BiOp’s determination of X2 was arbitrary and capricious.
    First of all, there was no abuse of discretion in the district
    court’s decision to admit the declarations of Aaron Miller, a
    DWR technical engineer who worked closely with
    Reclamation to develop Calsim II, which were relevant to the
    Calsim II-Dayflow comparison. See Lands Council, 
    395 F.3d at
    1030 n.11. No battle of the experts was created by doing
    so: Miller’s assessment of the validity of the Calsim II-
    Dayflow comparison was consistent with the testimony of
    Rule 706 experts Drs. Quinn and Punt, who recognized
    Miller’s assessment; and the declarations of FWS hydrologist
    Derek Hilts—whose credentials and experience are similar to
    Miller’s, and who helped draft the BiOp—were mostly
    unresponsive to Miller’s declarations on the several sources
    of bias that the comparison introduced. In my view, the
    district court relied on this extra-record evidence simply to
    determine whether FWS had considered all relevant factors,
    here, the sources of bias, see Nw. Envtl. Advocates, 
    460 F.3d at 1145
    , before relying on the comparison to analyze the
    158                 SAN LUIS V. JEWELL
    effects of proposed Projects operations on smelt and its
    habitat, including X2’s location. Doing so was well within
    the court’s role. Because highly technical matters were
    involved, it was difficult to determine if FWS considered all
    relevant factors without looking outside the record to see
    what matters should have considered, but were not. See
    Inland Empire Pub. Lands Council v. U.S. Forest Serv.,
    
    88 F.3d 754
    , 760 n.5 (9th Cir. 1996). The district court could
    not properly discharge its duty to engage in “‘substantial
    inquiry’” by simply taking FWS’s word that it had considered
    all relevant matters. See Asarco, 
    616 F.2d at 1160
    .
    FWS’s choice to use the Calsim II-Dayflow comparison
    was unsupported by the requisite reasoned analysis. See
    Ecology Ctr. v. Castaneda, 
    574 F.3d 652
    , 665 (9th Cir. 2009).
    Comments received from DWR and other entities—which
    were echoed by the Rule 706 experts’ testimony—alerted
    FWS to the several sources of bias, yet the only explanation
    in the BiOp for using the comparison was that a Calsim II to
    Calsim II comparison that FWS had conducted did not show
    differences that were expected. As the district court noted,
    the record did not reflect that FWS considered, much less
    recognized, the sources of bias. Furthermore, there are
    significant differences between the two models, including
    how X2 positions are determined. FWS would have to
    address these significant differences in some way to obtain
    information on which it could reasonably rely to base the
    BiOp’s conclusions, including Action 4 on the management
    of X2’s location. FWS was required to provide some
    evidence supporting its conclusions to ensure that no clear
    error of judgment rendered its actions arbitrary and
    capricious. See League of Wilderness Defenders-Blue
    Mountains Biodiversity Project v. U.S. Forest Serv., 
    549 F.3d 1211
    , 1218 (9th Cir. 2008). Appellants do not dispute that
    SAN LUIS V. JEWELL                     159
    the sources of bias existed, or that the biases were significant
    or material; and the clear purpose of requiring FWS to use the
    best scientific evidence available is to ensure that the ESA is
    not implemented haphazardly or based on surmise or
    speculation. See Pac. Coast Fed’n of Fishermen’s Ass’ns,
    
    426 F.3d at
    1094–95.
    Finally, I agree with the district court that FWS did not
    sufficiently explain why 74 km and 81 km were selected as
    critical points for X2 to preserve smelt habitat. The district
    court was not therefore required to give FWS deference on
    this matter, as FWS’s reasoning could not be reasonably
    inferred from the record. See San Luis & Delta-Mendota
    Water Auth., 
    672 F.3d at 700
    . As to the other justifying
    evidence, it either does not relate to the choice of critical
    points or it is undisputed that it was offered for the first time
    in post-judgment proceedings. I am reluctant to pass over the
    absence of an adequate explanation in the administrative
    record by relying on Appellants’ post-hoc rationalizations.
    See Humane Soc’y of United States v. Locke, 
    626 F.3d 1040
    ,
    1049–50 (9th Cir. 2010).
    3. I find no authority requiring FWS to address
    specifically and analyze, in the BiOp or administrative record,
    the question of whether the RPA meets the non-jeopardy
    elements. I also question the district court’s reliance on
    Greenpeace v. Nat’l Marine Fisheries Serv., 
    55 F. Supp. 2d 1248
     (W.D. Wash. 1999), for the proposition that there must
    be some explanation in the administrative record as to why
    FWS concluded that all four elements for a valid RPA were
    satisfied. Nonetheless, I would affirm the district court on
    this issue, because the record belies Appellants’ contention
    that DWR and Reclamation raised no concerns about the non-
    jeopardy elements. The record shows that concerns were
    160                  SAN LUIS V. JEWELL
    raised relating to RPA feasability and its relationship to the
    action’s intended purpose (providing water for various uses),
    and possibly to DWR’s and Reclamation’s authority to
    implement the RPA. Thus, under FWS’s own interpretation
    of § 402.02, it was required to consider and address these
    elements specifically in the instant BiOp or administrative
    record.
    4. Finally, as the action agency, Reclamation could not
    rely solely on FWS’s BiOp to establish conclusively its
    compliance with its substantive obligations under ESA § 7,
    because it could not delegate its responsibility to see that its
    actions would not jeopardize smelt, see Pyramid Lake,
    
    898 F.2d at 1415
    ; and as the action agency it could not
    blindly adopt FWS’s conclusions because it is ultimately
    responsible for ESA compliance, see City of Tacoma, Wash.
    v. Fed. Energy Regulatory Comm’n, 
    460 F.3d 53
    , 76 (D.C.
    Cir. 2006). I agree with the district court that Reclamation
    would be subject to independent ESA liability if it possessed
    new information not considered by FWS which challenged
    the BiOp’s conclusions, see Pyramid Lake, 898 F.3d at 1415,
    and that there is no indication that this occurred here. But the
    district court failed to consider another basis for finding an
    action agency independently liable, namely, reliance on a
    legally flawed BiOp. Discerning such flaws involves no
    technical or scientific expertise, so failure to do so may result
    in action based on reasoning not in accordance with the law
    thus rendering the action arbitrary and capricious. See Wild
    Fish Conservancy v. Salazar, 
    628 F.3d 513
    , 532 (9th Cir.
    2010). The district court’s legal conclusions necessarily
    arose from fact-finding, but the court clearly, and I believe
    correctly, concluded that FWS had not used the best available
    science or considered relevant factors, and had acted
    arbitrarily and capriciously, because, among other things, it
    SAN LUIS V. JEWELL                     161
    relied on the Calsim II-Dayflow comparison, and did not use
    normalized salvage data to set the flow prescription. The
    district court therefore should have found Reclamation
    independently liable under ESA § 7 for accepting a legally
    flawed BiOp and immediately beginning implementation of
    the RPA by modifying operations.
    In sum, I find no abuse of discretion in the district court’s
    limited admission of evidence outside the administrative
    record as relevant to the OMR flow limits and the
    determination of X2, including the use of the Calsim II-
    Dayflow comparison. I believe that in determining whether
    FWS’s decisions on these matters in the BiOp were arbitrary,
    capricious, or otherwise not in accordance with the law, the
    district court’s analysis was thorough and well-reasoned.
    While I disagree with the basis for the district court’s
    conclusion that the non-jeopardy elements must be addressed
    in the BiOp or administrative record, I nonetheless believe
    that affirmance is warranted on this issue. Finally, I believe
    the district court should have found Reclamation
    independently liable under the ESA for relying on a legally
    flawed BiOp.
    RAWLINSON, Circuit Judge, concurring in part and
    dissenting in part:
    I concur in the bulk of the majority opinion. I disagree
    only with the rationale and conclusion that the Bureau of
    Reclamation’s adoption and implementation of the Biological
    Opinion triggered its obligation to comply with the National
    Environmental Policy Act (NEPA) by preparing an
    162                 SAN LUIS V. JEWELL
    Environmental Impact Statement that is generally required
    under the Endangered Species Act.
    It is important to keep in mind that the Bureau of
    Reclamation adopted and implemented the detailed
    Biological Opinion in this case to alleviate harm to threatened
    and endangered species and/or their critical habitat caused by
    operation of the federally operated Central Valley Water
    Project and the state operated State Water Project.
    As an initial matter, I do not agree that the adoption of
    “reasonable and prudent alternatives” to alleviate harm to
    threatened and endangered species and/or their critical habitat
    from ongoing operations of the water projects constituted a
    “major Federal action” triggering the requirement of an
    Environmental Impact Statement.             See 
    42 U.S.C. § 4332
    (2)(C) (requiring the preparation of an Environmental
    Impact Statement for “major Federal actions”). I am
    persuaded toward that view by our rationale in two cases with
    facts similar to those in this case. The first is Upper Snake
    River Chapter of Trout Unlimited v. Hodel, 
    921 F.2d 232
     (9th
    Cir. 1990). In Upper Snake River, the panel posed the
    following question: “Did the District Court err in concluding
    that the National Environmental Policy Act) (“NEPA”) did
    not require the Bureau of Reclamation (“Bureau”) to prepare
    environmental impact statements (“EIS”) before periodically
    adjusting the flow of water from the Palisades Dam?” The
    panel responded: “We are clear that the answer is ‘No.’” 
    Id. at 233
    .
    To apply the reasoning of Upper Snake River, we need
    only change the name of the dam in the question posed. To
    me, the answer is equally clear. The Bureau of Reclamation
    was not required to prepare an Environmental Impact
    SAN LUIS V. JEWELL                    163
    Statement when it adopted the reasonable and prudent
    alternatives from the Biological Opinion to set flow limits for
    water controlled by the Central Valley water project.
    Much like the water supply in the Central Valley, the
    amount of water in the Snake River “fluctuates considerably
    from year to year, depending on the amount of snow pack in
    the mountains. . . .” 
    Id.
     Water from the river is captured in
    reservoirs and the water flow is controlled and regulated by
    dams. See 
    id.
     The Plaintiffs challenged the Bureau of
    Reclamation’s decision to reduce the flow rate below 1,000
    cubic feet per second in times of less precipitation. See 
    id. at 234
    . In rejecting the contention that NEPA was applicable,
    the district court held:
    In the case of the Palisades Dam, the
    fluctuating flows are routine actions which are
    contingent upon Mother Nature for snow-
    pack, runoff, precipitation and carryover. As
    part of its routine and ongoing operations, the
    Bureau of Reclamation fluctuates the flows
    depending upon weather conditions past and
    future.      Overall, the Court views the
    fluctuation of flows below Palisades as
    “ongoing operations,” which do not have to
    comply with . . . NEPA.
    
    Id.
     (alterations omitted) (emphasis added).
    Once again and without equivocation, the panel
    concluded: “[W]e are clear that the district court’s
    conclusion was correct.” 
    Id.
     The panel explicitly determined
    that water flow fluctuation was not a “major Federal action”
    under NEPA. 
    Id.
     As with Central Valley operations, the
    164                   SAN LUIS V. JEWELL
    Palisades project was completed well before the effective date
    of NEPA. See 
    id.
     According to the panel, post-construction
    fluctuation of water flow constituted routine operation of the
    dam rather than a major action triggering NEPA
    requirements. See 
    id.
     at 234–35.
    The panel relied heavily on the reasoning in Trinity
    County v. Andrus, 
    438 F. Supp. 1368
     (E.D. Cal. 1977). In
    Trinity County, Plaintiffs sought an injunction prohibiting the
    Bureau of Reclamation from lowering the water level in the
    Central Valley water project during a drought year. See 
    id. at 1371
    . The district court framed the issue as “not whether the
    actions are of sufficient magnitude to require the preparation
    of an [Environmental Impact Statement], but rather whether
    NEPA was intended to apply at all to the continuing
    operations of completed facilities. . . .” 
    Id. at 1388
     (citation
    omitted).
    The district court distinguished water flow determinations
    from cases “when a project takes place in incremental stages
    of major proportions or when a revision or expansion of the
    original facilities is contemplated . . .” 
    Id.
     (citations omitted).
    The district court in Trinity County also noted that the Bureau
    of Reclamation had not enlarged its diversion capacity, or
    revised its procedures or standards for release of water or
    draws from reservoirs. See 
    id.
     at 1388–89. Under these
    circumstances, the requirements of NEPA simply were not
    triggered. See 
    id.
     Taking its cue from Trinity County, the
    panel in Upper Snake River reasoned that:
    The Federal defendants in this case had
    been operating the dam for upwards of ten
    years before the effective date of [NEPA].
    During that period, they have from time to
    SAN LUIS V. JEWELL                    165
    time and depending on the river’s flow level,
    adjusted up or down the volume of water
    released from the Dam. What they did in
    prior years and what they were doing during
    the period under consideration were no more
    than the routine managerial actions regularly
    carried on from the outset without change.
    They are simply operating the facility in the
    manner intended. In short, they are doing
    nothing new, nor more extensive, nor other
    than that contemplated when the project was
    first operational. . . .
    
    921 F.2d at 235
    .
    Because the Bureau of Reclamation similarly continued
    to do nothing more than “monitor[ ] and control . . . the flow
    rate to ensure that the most practicable conservation of water
    is achieved,” 
    id.
     at 235–36, the panel concluded that no
    Environmental Impact Statement was required. See 
    id. at 236
    ; see also Grand Canyon Trust v. United States Bureau of
    Reclamation, 
    691 F.3d 1008
    , 1021–22 (9th Cir. 2012), as
    amended (citing Upper Snake River and similarly concluding
    that execution of annual operating plans regulating
    fluctuations in water flow was “not a major federal action
    requiring compliance with NEPA”); Burbank Anti-Noise
    Group v. Goldschmidt, 
    623 F.2d 115
    , 116 (9th Cir. 1980)
    (“An EIS need not discuss the environmental effects of mere
    continued operation of a facility. . . .”) (citation omitted).
    The second case with similar facts is Douglas County v.
    Babbitt, 
    48 F.3d 1495
     (9th Cir. 1995). In Douglas County,
    the panel considered whether the designation of critical
    habitat under the Endangered Species Act required
    166                 SAN LUIS V. JEWELL
    compliance with NEPA. See 
    id. at 1497
    . In the process of
    deciding that issue, the panel focused on the difference
    between the requirements and purpose of NEPA and the
    requirements and purpose of the Endangered Species Act.
    “The [Endangered Species Act] furthers the goals of NEPA
    without demanding an [Environmental Impact Statement]. . .”
    
    Id. at 1506
     (emphasis added). Indeed, “[t]he [Endangered
    Species Act] is a substantive statute whose goal is to prevent
    extinction . . . By designating critical habitats . . . the
    Secretary is working to preserve the environment . . .” 
    Id. at 1506
     (citations and internal quotation marks omitted). The
    panel concluded that the designation of critical habitat
    “further[ed] the purpose of NEPA [and] [r]equiring the
    [agency] to file an EIS would only hinder its efforts at
    attaining the goal of improving the environment.” 
    Id.
    (citation and internal quotation marks omitted).
    In contrast to the substantive nature of the Endangered
    Species Act, “NEPA is essentially a procedural statute
    designed to insure that environmental issues are given proper
    consideration in the decisionmaking process. . . .” Trustees
    for Alaska v. Hodel, 
    806 F.2d 1378
    , 1382 (9th Cir. 1986)
    (citation omitted). “NEPA does not mandate particular
    results, but simply provides the necessary process to ensure
    that federal agencies take a hard look at the environmental
    consequences of their action.” Kootenai Tribe of Idaho v.
    Veneman, 
    313 F.3d 1094
    , 1115–16 (9th Cir. 2002), overruled
    in part on other grounds, Wilderness Soc’y v. United States
    Forest Serv., 
    630 F.3d 1173
    , 1178–79 (9th Cir. 2011)
    (citation and internal quotation marks omitted). “The purpose
    of NEPA is to provide a mechanism to enhance or improve
    the environment and prevent further irreparable damage.”
    Drakes Bay Oyster Co. v. Jewell, No. 13-15227, 
    2014 WL 114699
     at *12 (9th Cir. Jan. 14, 2014), as amended (citation
    SAN LUIS V. JEWELL                    167
    and internal quotation marks omitted). An Environmental
    Impact Statement implements the NEPA regulations by
    “rigorously explor[ing] and objectively evaluat[ing] all
    reasonable alternatives to a proposed action . . .” Southeast
    Alaska Conserv. Council v. Federal Highway Admin.,
    
    649 F.3d 1050
    , 1056 (9th Cir. 2011) (quoting 
    40 C.F.R. § 1502.14
    (a)). An agency does not violate NEPA by
    declining to re-examine alternatives that have previously been
    evaluated. See, e.g., Honolulu Traffic.com v. Federal Transit
    Admin., No. 13-15277, 
    2014 WL 607320
     at *6 (9th Cir.
    February 18, 2014).
    It is undisputed that the Biological Opinion “rigorously
    explore[d] and objectively evaluate[d] all reasonable
    alternatives” over hundreds of pages. 
    40 C.F.R. § 1502.14
    (a).
    Indeed, the express purpose of the Biological Opinion was to
    develop reasonable and prudent alternatives to the existing
    activities that were harmful to the environment. See
    
    50 C.F.R. § 402.14
     (setting forth formal consultation
    procedures to ensure that the impact of proposed actions on
    listed species and their critical habitat are fully considered);
    see also Save the Yak Committee v. Block, 
    840 F.2d 714
    , 718
    (9th Cir. 1988), as amended (noting the NEPA requirement
    that an environmental assessment “include brief discussions
    of the environmental impacts of the proposed action and
    alternatives”) (emphasis added).
    As with the habitat listing in Douglas County, the
    Biological Opinion in this case served the same function as an
    Environmental Impact Statement. See 
    48 F.3d at 1498
     (“The
    EIS is a procedural obligation designed to assure that
    agencies give proper consideration to the environmental
    consequences of their actions. . . .”) (citation and internal
    quotation marks omitted). Because the NEPA requirements
    168                  SAN LUIS V. JEWELL
    are designed to “provide a mechanism to enhance or improve
    the environment and prevent further irreparable damage” to
    the environment, no Environmental Impact Statement is
    needed “for federal actions that conserve the
    environment. . . .” 
    Id. at 1505
     (citation and footnote reference
    omitted). In this circumstance, as in Douglas County, “the
    NEPA procedure seem[s] superfluous.” 
    Id. at 1503
     (internal
    quotation marks omitted). As the panel recognized in Drakes
    Bay, if the federal decision “is essentially an environmental
    conservation effort,” NEPA obligations are not triggered.
    
    2014 WL 114699
     at *12. The panel explained that the
    Endangered Species Act “furthers the goals of NEPA without
    demanding an EIS. . . .” 
    Id.
     (quoting Douglas County,
    
    48 F.3d at 1505, 1506
    ) (emphasis in Drakes Bay). We should
    be similarly “reluctant to make NEPA more of an
    obstructionist tactic to prevent environmental protection than
    it may already have become.” Id. at *13 (quoting Douglas
    County, 
    48 F.3d at 1508
    ). At this point, imposing an overlay
    of NEPA requirements “would only hinder [the Bureau of
    Reclamation’s] efforts at attaining the goal of improving the
    environment.” Douglas County, 
    48 F.3d at 1506
     (citation
    omitted). See Majority Opinion, p. 149 ([T]he preparation of
    an EIS will not alter Reclamation’s obligations under the
    ESA. . . .”). There is no need to require the Bureau of
    Reclamation to engage in scientific busywork. “This case
    simply does not present the type of situation NEPA was
    intended to address.” Burbank Anti-Noise Group, 
    623 F.2d at 117
    .
    I respectfully dissent.
    

Document Info

Docket Number: 11-15871

Filed Date: 3/13/2014

Precedential Status: Precedential

Modified Date: 10/14/2015

Authorities (91)

catron-county-board-of-commissioners-new-mexico-v-united-states-fish-and , 75 F.3d 1429 ( 1996 )

state-of-alabama-ex-rel-don-siegelman-attorney-general-alabamians-for-a , 911 F.2d 499 ( 1990 )

ARIZONA CATTLE GROWERS'ASS'N v. Salazar , 606 F.3d 1160 ( 2010 )

friends-of-the-earth-incorporated-citizens-local-environmental-action , 204 F.3d 149 ( 2000 )

Pacific Legal Foundation v. Cecil B. Andrus , 657 F.2d 829 ( 1981 )

Public Citizen Health Research Group v. United States ... , 557 F.3d 165 ( 2009 )

northwest-ecosystem-alliance-center-for-biological-diversity-tahoma-audubon , 475 F.3d 1136 ( 2007 )

kern-county-farm-bureau-kern-county-water-agency-north-kern-county-water , 450 F.3d 1072 ( 2006 )

native-ecosystems-council-v-united-states-forest-service-an-agency-of-the , 428 F.3d 1233 ( 2005 )

League of Wilderness Defenders-Blue Mount. Biodiversity ... , 549 F.3d 1211 ( 2008 )

pacific-coast-federation-of-fishermens-associations-institute-for , 426 F.3d 1082 ( 2005 )

inland-empire-public-lands-council-a-non-profit-corporation-montana , 88 F.3d 754 ( 1996 )

upper-snake-river-chapter-of-trout-unlimited-idaho-environmental-council , 921 F.2d 232 ( 1990 )

San Luis & Delta-Mendota Water Authority v. United States , 672 F.3d 676 ( 2012 )

Western Watersheds Project v. Kraayenbrink , 632 F.3d 472 ( 2011 )

port-of-astoria-oregon-an-oregon-municipal-corporation-concerned , 595 F.2d 467 ( 1979 )

churchill-county-city-of-fallon-v-gale-a-norton-in-her-official-capacity , 276 F.3d 1060 ( 2001 )

tim-jones-nancy-james-lethcoe-wendy-simpson-alaska-wilderness-sailing , 792 F.2d 821 ( 1986 )

97-cal-daily-op-serv-7390-97-daily-journal-dar-11916-american , 126 F.3d 1118 ( 1997 )

The Lands Council v. McNair , 537 F.3d 981 ( 2008 )

View All Authorities »