                 FOR PUBLICATION
 UNITED STATES COURT OF APPEALS
      FOR THE NINTH CIRCUIT

CENTER FOR BIOLOGICAL DIVERSITY,      
                        Petitioner,
                v.
UNITED STATES BUREAU OF LAND
MANAGEMENT; U.S. FISH AND                No. 10-72356
WILDLIFE SERVICE,
                      Respondents,
RUBY PIPELINE, L.L.C.,
           Respondent-Intervenor.
                                      

COALITION OF LOCAL GOVERNMENTS,       
ON BEHALF OF ITS MEMBERS,
INCLUDING LINCOLN COUNTY,
WYOMING,
                        Petitioner,
                v.                       No. 10-72552
BUREAU OF LAND MANAGEMENT;
DEPARTMENT OF THE INTERIOR,
                      Respondents,
RUBY PIPELINE, L.L.C.,
            Respondent-Intervenor.
                                      




                           12707
12708     CENTER FOR BIOLOGICAL DIVERSITY v. BLM



WARNER BARLESE, Member,               
Summit Lake Paiute Tribe,
Nevada, and Chairman, Summit
Lake Paiute Council,                      No. 10-72762
                        Petitioner,
                                           IBLM Nos.
                v.
                                      
                                          NVN-084650
UNITED STATES BUREAU OF LAND                OR-64807
MANAGEMENT; U.S. ARMY CORP OF              UTU-82880
ENGINEERS; U.S. FISH AND WILDLIFE         WYW-171168
SERVICE,                                    (W0350)
                      Respondents,
RUBY PIPELINE, L.L.C.,
            Respondent-Intervenor.
                                      

FORT BIDWELL INDIAN                   
COMMUNITY OF THE FORT BIDWELL
INDIAN RESERVATION OF CALIFORNIA,
                        Petitioner,
                v.
UNITED STATES BUREAU OF LAND
MANAGEMENT; U.S. FISH AND
                                         No. 10-72768
WILDLIFE SERVICE; UNITED STATES
ARMY CORPS OF ENGINEERS,
                      Respondents,
RUBY PIPELINE, L.L.C.,
           Respondent-Intervenor.
                                      
            CENTER FOR BIOLOGICAL DIVERSITY v. BLM              12709



DEFENDERS OF WILDLIFE; SIERRA             
CLUB; GREAT BASIN RESOURCE
WATCH,
                       Petitioners,
RUBY PIPELINE, L.L.C.,                            No. 10-72775

                                          
                       Intervenor,                  IBLM No.
                v.                                 CP09-54-000
UNITED STATES BUREAU OF LAND                        OPINION
MANAGEMENT; UNITED STATES
ARMY CORPS OF ENGINEERS; U.S.
FISH AND WILDLIFE SERVICE,
                     Respondents.
                                          
           On Petition for Review of Orders of the
             Bureau of Land Management and
               the Fish and Wildlife Service

                   Argued and Submitted
             October 11, 2011—Portland, Oregon

                     Filed October 22, 2012

       Before: Marsha S. Berzon and N. Randy Smith,
   Circuit Judges, and William E. Smith, District Judge.*

                    Opinion by Judge Berzon




  *The Honorable William E. Smith, District Judge for the U.S. District
Court for the District of Rhode Island, sitting by designation.
           CENTER FOR BIOLOGICAL DIVERSITY v. BLM       12713




                         COUNSEL

Eric. R. Glitzenstein (argued), Meyer Glitzenstein & Crystal,
Washington, D.C., for petitioners Center for Biological Diver-
sity and Defenders of Wildlife et al. Amy R. Atwood, Center
for Biological Diversity, Portland, Oregon, John T. Buse,
Center for Biological Diversity, San Francisco, California,
Howard M. Crystal, Meyer Glitzenstein & Crystal, Washing-
ton, D.C., for petitioner Center for Biological Diversity.
Adam M. Kron, Kara Gillon, Michael P. Senatore, Defenders
of Wildlife, Washington, D.C., for petitioner Defenders of
Wildlife et al.

Randolph H. Barnhouse, Samuel D. Hough (argued), Luebben
Johnson & Barnhouse LLP, Los Ranchos De Albuquerque,
New Mexico, for petitioner Fort Bidwell Indian Community
of the Fort Bidwell Indian Reservation of California.

Colette Routel (argued), Assistant Professor, William Mitch-
ell College of Law, Saint Paul, Minnesota, for petitioner Sum-
mit Lake Paiute Tribe.

Constance E. Brooks, Michael Marinovich (argued), C.E.
Brooks & Associates, P.C., Denver, Colorado, for petitioner
Coalition of Local Governments.

Nicholas A. DiMascio, Lane N. McFadden, Jennifer S. Neu-
mann (argued), U.S. Department of Justice, Environment &
Natural Resources Division, Washington, D.C., for respon-
dents U.S. Bureau of Land Management, U.S. Fish and Wild-
life Service.

John A. Bryson (argued), John F. Clark, Holland & Hart LLP,
Washington, D.C., William G. Myers III, Holland & Hart
12714        CENTER FOR BIOLOGICAL DIVERSITY v. BLM
LLP, Boise, Idaho, Aaron C. Courtney, Stoel Rives LLP,
Portland, Oregon, Craig V. Richardson, El Paso Corporation
Pipeline Group, Colorado Springs, Colorado, Thomas L. San-
sonetti, Holland & Hart LLP, Cheyenne, Wyoming, Troy A.
Eid, Jennifer H. Weddle, Greenberg Traurig LLP, Denver,
Colorado, for respondent-intervenor Ruby Pipeline, L.L.C.


                              OPINION

BERZON, Circuit Judge:

   Our case concerns a decision by the Bureau of Land Man-
agement (“BLM”) to authorize the Ruby Pipeline Project
(“Project”). The Project involves the construction, operation,
and maintenance of a 42-inch-diameter natural gas pipeline
extending from Wyoming to Oregon, over 678 miles. The
right-of-way for the pipeline encompasses approximately
2,291 acres of federal lands and crosses 209 rivers and
streams that support federally endangered and threatened fish
species. According to a Biological Opinion (“the Biological
Opinion” or “the Opinion”) formulated by the Fish and Wild-
life Service (“FWS”), the project “would adversely affect”
nine of those species and five designated critical habitats. The
FWS nonetheless concluded that the project “would not jeop-
ardize these species or adversely modify their critical habitat.”
The propriety of the FWS’s “no jeopardy” conclusion, and the
BLM’s reliance on that conclusion in issuing its Record of
Decision, are at the heart of this case.

   This opinion addresses those challenges to the Project that
petitioners Center for Biological Diversity, Defenders of
Wildlife et al., and Summit Lake Paiute Tribe have raised
under the Endangered Species Act (“ESA”), 16 U.S.C. § 1531
et seq.1 Specifically, we resolve petitioners’ claims that the
  1
  We address the remaining issues raised by the petitioners in a separate
memorandum disposition filed concurrently with this opinion.
              CENTER FOR BIOLOGICAL DIVERSITY v. BLM                  12715
Biological Opinion and its accompanying Incidental Take
Statement were arbitrary and capricious because: (1) the Bio-
logical Opinion’s “no jeopardy” and “no adverse modifica-
tion” determinations relied on protective measures set forth in
a conservation plan not enforceable under the ESA; (2) the
Biological Opinion did not take into account the potential
impacts of withdrawing 337.8 million gallons of groundwater
from sixty-four wells along the pipeline; (3) the Incidental
Take Statement miscalculated the number of fish to be killed,
by using a “dry-ditch construction method” for water cross-
ings; and (4) the Incidental Take Statement placed no limit on
the number of “eggs and fry” of threatened Lahontan cut-
throat trout to be taken during construction.

   We agree with the first two contentions and so set aside the
Biological Opinion as arbitrary and capricious. We also set
aside the Record of Decision, as it relied on the invalid Bio-
logical Opinion.2

                         I.   BACKGROUND

A.    Statutory Scheme

   The Endangered Species Act is a comprehensive scheme
with the “broad purpose” of protecting endangered and threat-
ened species. Babbit v. Sweet Home Chapter of Comtys. for
a Great Or., 515 U.S. 687, 698 (1995); see Tenn. Valley Auth.
v. Hill, 437 U.S. 153, 180 (1978). Two interlocking provi-
sions of the Act are of particular significance here: section 9,
which prohibits the “take”3 of any member of an endangered
  2
     That the pipeline was completed and put into service during the pen-
dency of this lawsuit does not render the petitioners’ challenges moot. It
is still possible to mitigate the Project’s adverse effects on listed species
and critical habitat. Compare Pyramid Lake Paiute Tribe of Indians v.
Hodel, 882 F.2d 364, 368-69 (9th Cir. 1989), with Feldman v. Bomar, 518
F.3d 637, 642-44 (9th Cir. 2008).
   3
     “The term ‘take’ means to harass, harm, pursue, hunt, shoot, wound,
kill, trap, capture, or collect, or to attempt to engage in any such conduct.”
16 U.S.C. § 1532(19).
12716         CENTER FOR BIOLOGICAL DIVERSITY v. BLM
or threatened species, 16 U.S.C. § 1538(a)(1)(B), and section
7, which imposes upon federal agencies an “affirmative duty
to prevent violations of section 9,” Ariz. Cattle Growers’
Ass’n v. U.S. Fish & Wildlife, 273 F.3d 1229, 1238 (9th Cir.
2001) (citing 16 U.S.C. § 1536(a)(2)).

   Under Section 7, a federal agency must “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 [critical] habitat of
such species.” 16 U.S.C. § 1536(a)(2).4 To facilitate compli-
ance with this substantive requirement, section 7 and its
implementing regulations also impose specific procedural
duties upon federal agencies: Before beginning any “major
construction activities,” agencies must prepare a “biological
assessment” to determine whether listed species or critical
habitat “are likely to be adversely affected” by the proposed
action. 50 C.F.R. § 402.12 (2012). If so, the action agency
must formally consult with the appropriate wildlife agency, in
this case the FWS,5 before undertaking the action. 50 C.F.R.
§ 402.14; see Karuk Tribe of Cal. v. U.S. Forest Serv., 681
F.3d 1006, 1020 (9th Cir. 2012) (en banc); Sierra Club v.
Babbitt, 65 F.3d 1502, 1505 (9th Cir. 1995).

   During the formal consultation process, the FWS must
  4
     The ESA defines “critical habitat” as: (i) areas occupied by the species,
at the time the species is “listed” as endangered or threatened under the
Act, that contain “those physical or biological features (I) essential to the
conservation of the species and (II) which may require special manage-
ment considerations or protection;” and (ii) areas not occupied by the spe-
cies at the time of listing that are determined by the Secretary of the
Interior to be “essential for the conservation of the species.” 16 U.S.C.
§ 1532(5)(A).
   5
     The FWS administers the Act with respect to all species aside from
marine species, which fall within the jurisdiction of the National Marine
Fisheries Service (NMFS). See 50 C.F.R. § 402.01; Westlands Water Dist.
v. U.S. Dep’t. of Interior, 376 F.3d 853, 873 (9th Cir. 2004).
             CENTER FOR BIOLOGICAL DIVERSITY v. BLM                  12717
“[f]ormulate its biological opinion as to whether the action,
taken together with cumulative effects, is likely to jeopardize
the continued existence of listed species or result in the
destruction or adverse modification of critical habitat.” 50
C.F.R. § 402.14(g)(4). If the FWS concludes that jeopardy or
adverse modification is likely, then any take resulting from
the proposed action is subject to section 9 liability (unless that
take is authorized by other provisions of the Act not relevant
here). See Sierra Club v. Babbitt, 65 F.3d at 1505; Defenders
of Wildlife v. EPA, 420 F.3d 946, 966 (9th Cir. 2005), rev’d
on other grounds by Nat’l Ass’n of Home Builders v. Defend-
ers of Wildlife, 551 U.S. 644 (2007). Although a federal
agency or project applicant is “technically free to disregard
the Biological Opinion and proceed with its proposed action,
. . . it does so at its own peril (and that of its employees), for
‘any person’ who knowingly ‘takes’ [a member of] an endan-
gered or threatened species is subject to substantial civil and
criminal penalties, including imprisonment.” Bennett v. Spear,
520 U.S. 154, 170 (1997); see also San Luis & Delta-
Mendota Water Auth. v. Salazar, 638 F.3d 1163, 1170 (9th
Cir. 2011) (“[T]he determinative or coercive effect of a Bio-
logical Opinion stems directly from the Service’s power to
enforce the no-take provision in ESA § 9 . . . .”).

   If, on the other hand, the FWS concludes in its biological
opinion that no jeopardy or adverse modification is likely, but
that the project is likely to result only in the “incidental take”6
of members of listed species, then the FWS will provide,
along with its biological opinion, an incidental take statement
authorizing such takings. 50 C.F.R. § 402.14(i). An incidental
take statement must:

      (1) specify the impact [i.e., the amount or extent] of
      the incidental taking on the species; (2) specify the
  6
   “Incidental take refers to takings that result from, but are not the pur-
pose of, carrying out an otherwise lawful activity conducted by the Federal
agency or applicant.” 50 C.F.R. § 402.02.
12718      CENTER FOR BIOLOGICAL DIVERSITY v. BLM
    “reasonable and prudent measures” that the FWS
    considers necessary or appropriate to minimize such
    impact; [and] (3) set forth “terms and conditions”
    with which the action agency must comply to imple-
    ment the reasonable and prudent measures . . . .

Or. Natural Res. Council v. Allen, 476 F.3d 1031, 1034 (9th
Cir. 2007) (quoting 16 U.S.C. § 1536(b)(4); 50 C.F.R.
§ 402.14(i)). “Significantly, the Incidental Take Statement
functions as a safe harbor provision immunizing persons from
Section 9 liability and penalties for takings committed during
activities that are otherwise lawful and in compliance with its
terms and conditions.” Ariz. Cattle Growers’ Ass’n, 273 F.3d
at 1239 (citing 16 U.S.C. § 1536(o)).

   ESA regulations further require federal agencies and proj-
ect applicants to “monitor the impacts of incidental take” by
“report[ing] the progress of the action and its impact on the
species” to the FWS. 50 C.F.R. § 402.14(i)(3). If the amount
or extent of incidental taking is exceeded, the action agency
“must immediately reinitiate consultation with the FWS.”
Allen, 476 F.3d at 1034-35 (citing 50 C.F.R. §§ 402.14(i)(4),
402.16(a)). The action agency must also reinitiate consulta-
tion if the proposed action “is subsequently modified in a
manner that causes an effect to the listed species or critical
habitat that was not considered in the biological opinion.” 50
C.F.R. § 402.16(c); see also Defenders of Wildlife v. Flowers,
414 F.3d 1066, 1070 (9th Cir. 2005). When reinitiation of
consultation is required, the original biological opinion loses
its validity, as does its accompanying incidental take state-
ment, which then no longer shields the action agency from
penalties for takings. See Allen, 476 F.3d at 1037; U.S. Fish
& Wildlife Serv. & Nat. Marine Fisheries Serv., Endangered
Species Consultation Handbook: Procedures for Conducting
Consultation and Conference Activities under Section 7 of the
Endangered Species Act 4-23 (1998) [hereinafter ESA Hand-
book].
            CENTER FOR BIOLOGICAL DIVERSITY v. BLM          12719
B.   The Ruby Pipeline Project: Formal Consultation and
     the Biological Opinion

  In January 2009, Respondent-Intervenor Ruby Pipeline
L.L.C. (“Ruby”) filed a formal application with the Federal
Energy Regulatory Commission (FERC) seeking a Certificate
of Public Convenience and Necessity (“Certificate”), see 15
U.S.C. § 717f(c)(1)(A), authorizing the Project. After Ruby
and FERC had agreed on the rough scope of the project,
FERC requested consultation with the FWS about the pro-
posed license.

   FWS’s resulting Biological Opinion focused on nine listed
species it determined the Project “would adversely affect,” as
well as the 209 bodies of water the Project would cross that
either fall within or connect to the listed species’ critical habi-
tats. Five of the species—Lahontan cutthroat trout, Warner
sucker, Lost River Sucker, shortnose sucker, and Modoc
sucker—inhabit waters in Nevada, Oregon, or both. The other
four species—Colorado pikeminnow, humpback chub, razor-
back sucker, and bonytail chub—live in the Colorado River
system. The FWS determined that the first group of species,
the Nevada/Oregon group, would be adversely affected by the
Project’s stream crossings, while the second group, those in
the Colorado River system, would be adversely affected by
the use and depletion of ground and surface water during con-
struction.

   Crucially, the Biological Opinion factored into its jeopardy
determination several “voluntary” conservation actions Ruby
had indicated it would facilitate implementing, which the
Opinion identified as “reasonably certain to occur.” The
Opinion explained that these actions, set forth in an Endan-
gered Species Conservation Action Plan (sometimes “CAP”),
were “to be implemented by Ruby in the future,” “would be
beneficial to listed fishes and their habitats, and . . . [would]
eventually contribute to the conservation and recovery of
these fishes.” Whether the Biological Opinion properly relied
12720        CENTER FOR BIOLOGICAL DIVERSITY v. BLM
upon the Conservation Action Plan as mitigating the adverse
effects of the Project is the central issue in this case.7

   Although it recognized that the Project would adversely
affect the nine listed species, the Biological Opinion ulti-
mately concluded that the Project was “not likely to jeopar-
dize the continued existence” of these species or “adversely
modify or destroy designated critical habitat.” The FWS
therefore provided an Incidental Take Statement authorizing
“mortality to Lahontan cutthroat trout, Warner sucker, Modoc
sucker, Lost River sucker, and shortnose sucker,” provided
the specified terms and conditions were met. It also “exemp-
t[ed from section 9 liability] all take in the form of harm that
would occur from the Project’s removal of 49.5 acre-feet of
water” from the Colorado River Basin.

                        II.   DISCUSSION

   The Administrative Procedure Act (“APA”) governs our
review of agency decisions under the ESA. Karuk Tribe, 681
F.3d at 1017. Under the APA, an agency action is valid unless
it is “ ‘arbitrary, capricious, an abuse of discretion, or other-
wise not in accordance with law.’ ” Id. (quoting 5 U.S.C.
§ 706(2)(A)). An agency action is arbitrary and capricious if
the agency has:

      relied on factors which Congress has not intended it
      to consider, entirely failed to consider an important
      aspect of the problem, offered an explanation for its
      decision that runs counter to the evidence before the
      agency, or is so implausible that it could not be
      ascribed to a difference in view or the product of
      agency expertise.
  7
    We provide further detail regarding the origin and nature of the Con-
servation Action Plan in Part II.A of the opinion, which addresses that
issue.
               CENTER FOR BIOLOGICAL DIVERSITY v. BLM      12721
Pac. Coast Fed’n of Fishermen’s Ass’ns v. Nat’l Marine Fish-
eries Serv., 265 F.3d 1028, 1034 (9th Cir. 2001) (quoting
Motor Vehicle Mfrs. Ass’n v. State Farm, 463 U.S. 29, 43
(1983)).

A.     The Conservation Action Plan

   The petitioners’ central argument is that the Biological
Opinion was arbitrary and capricious because it relied in part
on the projected beneficial effects of the Conservation Action
Plan for its conclusion that the Project would not jeopardize
the nine listed fish species or adversely affect critical habitat.
The Conservation Action Plan measures are unenforceable
under the procedures established by the ESA, petitioners
maintain, but should be, and so cannot be relied upon in
assessing the likely impact of the project on listed species.
Unless the Conservation Action Plan is binding under the
ESA, the FWS will be unable to use the ESA’s “strict civil
and criminal penalties,” Gifford Pinchot Task Force v. U.S.
Fish & Wildlife Serv., 378 F.3d 1059, 1063 (9th Cir. 2004),
to ensure that the plan is implemented. We agree that the
Opinion’s reliance on the CAP is inconsistent with the statu-
tory scheme, and that the Opinion is therefore invalid.

  1.        Background

       a.    Development and features of the Conservation
             Action Plan

   In May 2009, FWS staff sent Ruby an “ESA Mitigation and
Conservation Action Plan Proposal,” suggesting measures
that “would address Ruby[’s] impacts to listed species and
their critical habitats as well as assist with recovery of these
listed species.” The FWS requested that Ruby file the final
Conservation Action Plan with FERC so it could “be included
as part of the final biological assessment.” This approach, it
appears, would have rendered the Conservation Action Plan
12722      CENTER FOR BIOLOGICAL DIVERSITY v. BLM
part of the proposed action, and so enforceable under the
ESA. See further discussion at p.12727, infra.

   FWS staff then produced a draft Memorandum of Agree-
ment to establish a proposed Conservation Action Plan; the
Memorandum attached the Conservation Action Plan that
would be the subject of the Agreement. Both documents were
revised several times. During the revision process, FERC, the
action agency, objected to the inclusion of the Conservation
Action Plan as part of the proposed action. The FWS there-
upon revised the draft Memorandum of Agreement “to repre-
sent a stand-alone agreement between Ruby and [the]
agencies,” “delet[ing] [the] previous assumption that this
Memorandum of Agreement and ESA conservation action
plan would be part of the FERC proposed [section 7] action.”
FWS staff also noted that Ruby contributed language to the
revised draft “to provide rationale that the ESA conservation
action plan, while related to the ESA proposed action, [was]
not interrelated or interdependent for purposes of section 7
effects analysis.”

   Ultimately, the Memorandum of Agreement was made final
and renamed the “Letter of Commitment by Ruby Pipeline
LLC regarding the Endangered Species Act Conservation
Action Plan for the Ruby Pipeline Project” (“Letter”). The
Letter spelled out the nature of and limits on Ruby’s commit-
ment “to fund and/or implement conservation measures for
the benefit of federally threatened and endangered species that
occur within the Ruby Pipeline Project . . . action area.” Nota-
bly, it characterized the Conservation Action Plan as entirely
independent of the requirements of section 7 of the ESA:

    Separately, and not in lieu of FERC’s . . . Section 7
    consultation responsibility, Ruby has agreed to com-
    mit to fund conservation actions that are beneficial
    to listed species and their habitats that occur within
    the Ruby Project action area, and that will contribute
           CENTER FOR BIOLOGICAL DIVERSITY v. BLM         12723
    to the conservation and recovery of these species.
    . . . This Plan is not part of the FERC proposed
    action for ESA consultation and also is separate
    from, and in addition to, any reasonable and prudent
    measures developed as part of the Section 7 consul-
    tation with the Service for the Project. . . . [W]hile
    Ruby has committed to fund the conservation actions
    identified in the Plan to conserve and assist with
    recovery of these listed species, the Project is not
    dependent on these conservation actions. Con-
    versely, the conservation actions identified in the
    Plan involve projects that already had been identified
    by the Service . . . and thus could proceed regardless
    of whether the Project was authorized.

(Emphasis added.)

   To the Letter was attached a list of, among other things,
twelve fish-specific conservation measures; the Letter referred
to the attachment as “Ruby’s Endangered Species Act Conser-
vation Action Plan.” The listed conservation measures, if
completed, were to benefit each of the nine listed species that,
according to the Biological Opinion, the Project would
adversely affect. Included were the construction of a fish
migration barrier to protect Lahontan cutthroat trout from
invasive non-native trout; improvements to a road adjacent to
Modoc sucker spawning and rearing habitat; research and
monitoring of Warner sucker populations; and restoration of
native riparian vegetation along select tributaries in the Green
River Basin, to decrease water loss that could adversely
impact the endangered Colorado River fishes.

   Ruby committed to funding fully only seven of the twelve
Conservation Action Plan measures. For the remaining five
measures, Ruby agreed to contribute partial funding, with the
remaining funds to be “acquired via cost-share.” For four of
those five projects, Ruby’s partial contribution would amount
to twenty-five percent of the costs; the remaining seventy-five
12724      CENTER FOR BIOLOGICAL DIVERSITY v. BLM
percent would be “obtained from other sources.” For the
remaining partially-funded project, Ruby would pay
$150,000, leaving an unspecified amount of “remaining
funds” to be acquired elsewhere. The Letter of Commitment
indicated that it would be the FWS’s responsibility to obtain
cost-share funding. Ruby agreed, if the FWS were unable to
do so, to “pay any reasonable costs, as determined by Ruby
in its sole discretion . . . to ensure the identified conservation
action is completed.” (Emphasis added.)

   The Letter stated that “Ruby anticipate[d] that each of the
actions [would] be initiated within five years of Ruby’s
receipt of its Certificate” from FERC authorizing the Project.
(Emphasis added.) It further stated that, if any of the conser-
vation actions could not “be completed for any reason, Ruby
[would] work with the Service, other federal agencies, states
and/or NGO partners to identify another ESA conservation
action that will provide the same or greater conservation ben-
efit for the same species as the conservation action that was
originally identified.” Nothing in the Letter set forth any pen-
alties or other consequences to be imposed upon Ruby if
required CAP measures were underfunded or not imple-
mented.

   To the degree there are funding commitments, the CAP
measures are, however, in some measure enforceable, albeit
not through the ESA’s mechanisms. The Action Plan was
incorporated into both the FERC Certificate and the BLM’s
Record of Decision, each of which provides for discretionary
agency enforcement.

   First, as to the FERC Certificate, the Natural Gas Act
authorizes FERC to impose civil penalties of up to $1,000,000
per day for each violation of “any rule, regulation, restriction,
condition, or order made or imposed by [FERC].” Id. § 717t-
1(a). Condition 1 of the FERC Certificate for the Project
states that Ruby “shall follow” the “mitigation measures”
described in “its application, supplemental filings . . . , and as
             CENTER FOR BIOLOGICAL DIVERSITY v. BLM                12725
identified in the EIS,” and Appendix M to the FEIS includes
a version of the Conservation Action Plan.8

   Second, the regulations for the Mineral Leasing Act autho-
rize the BLM to suspend or terminate a right-of-way grant or
temporary use permit if an applicant does not “comply with
applicable laws and regulations or any terms, conditions, or
stipulations of the grant” or permit. 43 C.F.R. § 2886.17(a),
(b); see also 30 U.S.C. § 185(o). If the BLM terminates a
project’s grant or Temporary Use Permit, the applicant must
“remove any facilities within the right-of-way or TUP area
within a reasonable time, as determined by BLM, unless BLM
instructs . . . otherwise.” 43 C.F.R. § 2886.19(a). The BLM
may declare any facilities not removed to be the property of
the United States, while holding the company liable for costs
of removal “and for remediating and restoring the right-of-
way or TUP area.” Id. § 2886.19(c). Ruby therefore faces
potentially stiff consequences if it does not follow through
with its Conservation Action Plan commitments. But whether
to impose those consequences will be with the discretion of
FERC and BLM, with no role for FWS.

      b.   The Biological Opinion’s reliance on the
           Conservation Action Plan

   The Biological Opinion relied in part on the Conservation
Action Plan to conclude that the Project would not jeopardize
the continued existence of the nine listed fish or adversely
modify critical habitat. Specifically, the Biological Opinion’s
  8
    The version of the Conservation Action Plan included in Appendix M
of the FEIS is a draft and does not specify in any matter how much Ruby
would contribute for the conservation measures. The parties assume, how-
ever, that Condition 1 of the FERC Certificate renders binding the Conser-
vation Action Plan measures set forth in the final version of the plan,
attached to the March 18, 2010 Letter of Commitment. We shall so
assume as well for present purposes, although we can well imagine a dis-
pute on the matter should Ruby fail to fund the measures and be fined as
a result.
12726       CENTER FOR BIOLOGICAL DIVERSITY v. BLM
jeopardy analysis referenced the Conservation Action Plan
measures in its review of the Project’s anticipated “cumula-
tive effects,” that is, the “effects of future [non-Federal] activ-
ities . . . that are reasonably certain to occur within the action
area” of the Project. As the Biological Opinion explained:

    Ruby Pipeline LLC has voluntarily committed to
    fund several conservation actions in the action area
    that, when implemented in the future, would be ben-
    eficial to listed fish and their habitats, and that will
    eventually contribute to the conservation and recov-
    ery of these fishes. As noted in the Description of
    Proposed Action section, . . . FERC did not propose
    Ruby’s voluntary Endangered Species Conservation
    Action Plan conservation commitments as part of the
    BA’s proposed action. The Service considers these
    voluntary conservation actions to be reasonably cer-
    tain to occur, to be implemented by Ruby in the
    future, and therefore analyzes their effects herein this
    Cumulative Effects section of the [Biological Opin-
    ion].

  The Opinion went on to describe the individual CAP mea-
sures (without noting that funding of some of them was not
assured and that the measures might not be implemented for
years) and discuss their anticipated effects on listed species
and their habitats. With respect to impacts on the Lahontan
cutthroat trout, Warner sucker, Lost River Sucker, shortnose
sucker, and Modoc sucker, the Biological Opinion concluded:

    The Service . . . anticipates the nonfederal actions
    identified above that result in positive effects will
    expand listed fishes’ distributions, improve knowl-
    edge of fish needs and occurrences, and provide
    additional protection from entrainment-related mor-
    tality. From the standpoint of species survival and
    recovery, many of the beneficial conservation
    actions will have significant survival and recovery
                CENTER FOR BIOLOGICAL DIVERSITY v. BLM     12727
       benefit to individual species, especially for Lahontan
       cutthroat trout and Warner sucker, which will even-
       tually experience significant enhancement of habitat
       connectivity in the action area.

  2.        Analysis

   [1] The pivotal question is whether the FWS was permitted
to consider the CAP measures when determining whether the
Project would jeopardize listed species or adversely modify
critical habitat. An agency action is arbitrary and capricious
when the agency “relie[s] on factors which Congress has not
intended it to consider.” Pac. Coast Fed’n of Fishermen’s
Ass’ns, 265 F.3d at 1034 (quoting Motor Vehicle Mfrs. Ass’n,
463 U.S. at 43). Because the Plan should properly have been
part of the project itself, the FWS should not have treated its
anticipated benefits as background cumulative effects and
used them as a basis for determining the likely effects of the
Project. Doing so rendered the Plan unenforceable under the
ESA, depriving FWS of the power to ensure that the measures
were actually carried out.

       a.     Cumulative effects versus interrelated effects

   The Service’s ESA Handbook explains that the ESA jeop-
ardy determination turns on four considerations: “(1) the sta-
tus of the species, (2) the environmental baseline, (3) all
effects of the proposed action, and (4) the cumulative effects
of other anticipated actions.” ESA Handbook 4-37. To factor
into the jeopardy and adverse modification determinations,
the beneficial effects of the Conservation Action Plan mea-
sures must qualify as either “effects of the proposed action”
or “the cumulative effects of other anticipated actions,” id.;
see 50 C.F.R. § 402.14(g)(4), as the other two considerations
are inapplicable.

   “[E]ffects of the proposed action” encompass the effects of
“interrelated actions” which are “part of [the] larger action
12728       CENTER FOR BIOLOGICAL DIVERSITY v. BLM
and depend on the larger action for their justification.” 50
C.F.R. § 402.02. “The test for interrelatedness . . . is ‘but for’
causation: but for the federal project, these activities would
not occur.” Sierra Club v. Marsh, 816 F.2d 1376, 1387 (9th
Cir. 1987); accord ESA Handbook 4-27. “Interrelated actions”
include “conservation measures,” which the ESA Handbook
defines as “actions to benefit or promote the recovery of listed
species.” Id. at xii. Conservation measures “minimize or com-
pensate for” a project’s adverse effects to the species under
review and are an “integral part” of the proposed action. Id.
at xii, 4-19.

   In contrast, “cumulative effects” are “those effects of future
State or private activities, not involving Federal activities, that
are reasonably certain to occur within the action area of the
Federal action subject to consultation.” 50 C.F.R. § 402.02
(emphasis added). The ESA Handbook explains that “[f]uture
federal actions that are unrelated to the proposed action” are
not considered “cumulative effects,” because they require sep-
arate section 7 consultation. ESA Handbook at 4-31; accord
Marsh, 816 F.2d at 1387 (“The effects of unrelated private or
state activities that are reasonably certain to occur are ‘cumu-
lative effects.’ ”) (emphasis added).

   [2] Before addressing the categorization issue in this case,
we first explain why the answer to the categorization issue is
legally determinative. As we develop, whether the Biological
Opinion properly relied on the CAP in its jeopardy assess-
ment depends primarily upon whether it properly character-
ized the CAP’s projected benefits as “cumulative effects of
other anticipated actions,” rather than as “effects of the pro-
posed action.” ESA Handbook at 4-37.

    b.   Enforceability under the ESA

   The reason the categorization issue is the critical one is that
the unrelated, nonfederal actions giving rise to “cumulative
effects” are not enforceable under the ESA, meaning that:
             CENTER FOR BIOLOGICAL DIVERSITY v. BLM                 12729
they are not subject to the ESA consultation procedures; ESA
citizens’ suit provisions are not applicable; and they are not
enforceable through the threat of penalties for takings of listed
species if the mitigation conditions are not complied with.
Thus, while “cumulative effects” must be “reasonably certain
to occur,” 50 C.F.R. § 402.02; see Marsh, 816 F.2d at 1387,
they are essentially background considerations, relevant to the
jeopardy determination but not constituting federal actions
and so beyond the action agency’s power to effectuate. See 50
C.F.R. § 402.02. In contrast, “[s]ince conservation measures
are part of the proposed action, their implementation is
required under the terms of the consultation.”9 ESA Handbook
at 4-19.

  That the consultation concerning and enforceability of miti-
gation measures turns on their integration into the proposed
  9
   Generally speaking, measures that benefit a species can also be made
enforceable via incorporation into the “terms and conditions” of an Inci-
dental Take Statement. See 50 C.F.R. § 402.14(i)(1)(iv); see, e.g., Selkirk
Conservation Alliance v. Forsgren, 336 F.3d 944, 953 n.4 (9th Cir. 2003).
Whether measures specifically designed to offset the adverse impacts of
a proposed project should be categorized as “interrelated actions” that are
part of the proposed project or as “terms and conditions” of an Incidental
Take Statement depends on the nature of those measures.
   Specifically, only those measures that minimize a project’s incidental
takings are properly included in an Incidental Take Statement’s terms and
conditions. See 50 C.F.R. § 402.14(i)(1)(ii); accord ESA Handbook 4-19
(emphasizing that “the objective of the incidental take analysis under sec-
tion 7 is minimization, not mitigation”). Terms and conditions can include
only “minor changes” and “cannot alter the basic design, location, scope,
duration, or timing of the action.” 50 C.F.R. § 402.14(i)(2). Measures that
minimize incidental takings can factor into both jeopardy determinations
and incidental take analyses. ESA Handbook at 4-19.
   In contrast, measures that do not minimize incidental takings but none-
theless promote recovery of a species are properly considered “conserva-
tion actions” that are interrelated to a proposed project. The CAP projects
here do not minimize incidental takings associated with construction of the
pipeline and are therefore more appropriately considered “interrelated
actions” to the larger project.
12730      CENTER FOR BIOLOGICAL DIVERSITY v. BLM
action is illustrated by Sierra Club v. Marsh. In Marsh, we
held that “[t]he substantive and procedural provisions of the
ESA are the means determined by Congress to assure ade-
quate protection [of listed species].” 816 F.2d at 1384
(emphasis added). Marsh concerned a “no jeopardy” Biologi-
cal Opinion for a highway and flood control project, in which
the FWS relied on San Diego County’s planned acquisition
and preservation of 188 acres of mitigation marsh lands for its
conclusion that listed birds would not be affected. Id. at 1379-
80. But the County did not carry out its promise, and the
action agency, the U.S. Army Corps of Engineers, refused to
reinitiate consultation with FWS. We enjoined the project
until the Corps reinitiated consultation and “insure[d] the
acquisition of the mitigation lands or modifie[d] the project
accordingly.” Id. at 1389. In so holding, we relied on the sta-
tus of the land acquisition arrangement as part of the pro-
posed project: Because acquisition of the mitigation lands was
part of the project design, see id. at 1379, the change in the
project when the acquisition fell through triggered reinitiation
of formal consultation under the ESA regulations. See id. at
1388 (citing 50 C.F.R. § 402.16).

   As Marsh makes clear, if a non-federal party promises to
take action mitigating the impact of a federal action on listed
species but fails to do so, the contemplated protections of
listed species may never materialize. As we observed in
Thomas v. Peterson, “[i]f a project is allowed to proceed with-
out substantial compliance with [the ESA’s] procedural
requirements, there can be no assurance that a violation of the
ESA’s substantive provisions will not result. The latter, of
course, is impermissible.” 753 F.2d 754, 764 (9th Cir.1985);
see also Defenders of Wildlife v. Norton, 258 F.3d 1136, 1146
(9th Cir. 2001) (holding that the decision not to designate a
species of lizard for ESA protection was arbitrary and capri-
cious, in part because the decision relied on “the benefits
assertedly flowing from” a Conservation Agreement that the
signatory state and federal agencies failed to implement
fully).
           CENTER FOR BIOLOGICAL DIVERSITY v. BLM          12731
   In contrast, where, as in Marsh, conservation agreements
are part of the project design, the ESA’s sequential, interlock-
ing procedural provisions ensure recourse if the parties do not
honor or enforce the agreement, and so ensure the protection
of listed species. First, when a proposed action “is subse-
quently modified in a manner that causes an effect to the
listed species or critical habitat that was not considered in the
biological opinion,” the section 7 regulations require reinitia-
tion of formal consultation. 50 C.F.R. § 402.16(c). This
requirement provides the FWS with the opportunity—and the
obligation—to reexamine altered projects to ensure that any
changes will not place species in jeopardy or risk degradation
to critical habitat. As we held in Marsh, where mitigation
measures are not carried out, any risk to listed species thereby
created “must be borne by the project, not by the endangered
species.” See 816 F.2d at 1386.

   Second, where an action agency does not reinitiate consul-
tation with the FWS despite the failure of promised conserva-
tion measures, the Biological Opinion for the proposed action
becomes invalid. See ESA Handbook 4-23. Under these cir-
cumstances, the accompanying incidental take statement no
longer insulates the agency or applicant from the ESA’s “sub-
stantial civil and criminal penalties,” Bennett, 520 U.S. at 170,
for takings of listed species.

   Third, the ESA authorizes “any person” to bring suit to
enjoin any violation of the Act. 16 U.S.C. § 1540(g)(1)(A).
Noncompliance with the ESA’s procedural and substantive
requirements regarding compliance with mitigation measures
incorporated as part of the action project therefore exposes an
action agency and project applicant to citizen suits. The
ESA’s citizen suit provision plays an important role in the
protection of endangered species: its “obvious purpose is to
encourage enforcement.” Bennett, 520 U.S. at 170.

  Neither the Natural Gas Act nor the Mineral Leasing Act,
under which respondents argue the CAP measures are
12732      CENTER FOR BIOLOGICAL DIVERSITY v. BLM
enforceable, provide for either criminal penalties or citizen
suits. Moreover, “[t]he primary responsibility for insuring that
federal projects do not harm endangered species or their habi-
tats rests with the FWS.” Marsh, 816 F.2d at 1379. The FWS
is the federal agency with the greatest expertise in protecting
listed (non-marine) species, see id. at 1388, and the only
agency with the central purpose of conserving species. See
U.S. Fish & Wildlife Service, Who We Are, http://
www.fws.gov/who/ (last visited July 12, 2012); see also N.
Cal. River Watch v. Wilcox, 633 F.3d 766, 776 (9th Cir. 2011)
(underscoring “the degree of regulatory expertise necessary to
[ESA] enforcement”). Other agencies can, do, and indeed are
sometimes even required by statute to have competing priori-
ties. The Federal Land Policy and Management Act, for
example, mandates the BLM to “manage . . . public lands
under principles of multiple use.” 43 U.S.C. § 1732(a). This
responsibility entails taking into account not only the contin-
ued existence of “wildlife and fish,” but also future genera-
tions’ needs for “recreation, range, timber, [and] minerals,”
among other things. 43 C.F.R. § 1601.0-5(i). That the priori-
ties of other agencies can conflict with those of the FWS was
apparent in Marsh, 816 F.2d at 1381, and, as will appear, is
apparent here.

   In its discussion of section 7 of the ESA in TVA v. Hill, the
Supreme Court made clear that “Congress considered and
rejected language that would have permitted an agency to
weigh the preservation of species against the agency’s pri-
mary mission.” Marsh, 816 F.2d at 1383 (citing TVA v. Hill,
437 U.S. at 181-82). Here, categorizing the CAP measures as
private actions that produce only “cumulative effects”
removes them from the purview of the ESA, thereby eliminat-
ing the procedural protections of section 7 and circumscribing
the enforcement authority of the FWS. As reflected in the
FERC Certificate and BLM Record of Decision, enforcement
of these purportedly non-federal actions would be left to the
discretion of FERC and the BLM, and not to the FWS, the
expert agency entrusted with administering the ESA. Com-
           CENTER FOR BIOLOGICAL DIVERSITY v. BLM        12733
pare 30 U.S.C. § 185 (authorizing the Secretary of the Interior
to administer the Mineral Leasing Act with respect to rights-
of-way for natural gas transportation through federal lands),
and 43 C.F.R. § 3160.0-3 (delegating the Department of Inte-
rior’s functions under the Mineral Leasing Act, “except min-
eral revenue functions and the responsibility for leasing of
restricted Indian Lands,” to the Bureau of Land Management),
and 15 U.S.C. § 717o (delegating administration of the Natu-
ral Gas Act to FERC); with 16 U.S.C. § 1540 (entrusting
enforcement of the ESA to the Secretary of the Interior), and
50 C.F.R. § 402.01(b) (delegating to the FWS responsibilities
for administering the ESA).

   This arrangement would allow the action agencies to weigh
their own priorities against protection of the listed fish, as
those agencies have broad discretion as to enforcement
authority. For example, although FERC “shall” impose civil
penalties for violations of its conditions, the agency retains
the discretion to determine the magnitude of those penalties.
See 15 U.S.C. § 717t-1. Similarly, although the Mineral Leas-
ing Act authorizes the BLM to suspend the right-of-way or
temporary use permits for the pipeline should Ruby fail to
fund the CAP measures, those penalties are purely discretion-
ary. See 43 C.F.R. § 2886.17(a)-(b) (stating that the BLM
“may suspend or terminate” a right-of-way grant or temporary
use permits) (emphasis added). We lack assurance that the
BLM would, for instance, terminate the right-of-way for and
require removal of the pipeline—which has already been con-
structed and is delivering millions of gallons of natural gas
per day—in the event that Ruby fails to follow through with
the CAP measures.

   In sum, miscategorizing mitigation measures as “cumula-
tive effects” rather than conservation measures incorporated
in the proposed project profoundly affects the ESA scheme.
Any such miscategorization sidetracks the FWS, the primary
ESA enforcement agency; precludes reopening the consulta-
tion process when promised conservation measures do not
12734      CENTER FOR BIOLOGICAL DIVERSITY v. BLM
occur; and eliminates the possibility of criminal penalties and
exposure to citizen suit enforcement incorporated in the ESA
to assure that listed species are protected.

   Respondents maintain, however, that one of our precedents,
Selkirk Conservation Alliance v. Forsgren, 336 F.3d 944 (9th
Cir. 2003), allows the FWS to rely on promised conservation
measures as background “cumulative effects” for purposes of
the Biological Opinion, despite all of these adverse conse-
quences to the ESA scheme. Decidedly not so.

   In Selkirk, the FWS, concluding in a Biological Opinion
that the construction of roads through forest lands would not
jeopardize grizzly bears, “considered the effect of [a] Conser-
vation Agreement and concluded that, with the Agreement in
place, the overall effect of the [proposed] [p]roject [would]
not jeopardize the grizzly bears.” Id. at 952. The parties to the
Conservation Agreement included the FWS, the Forest Ser-
vice, and Stimson, the private company proposing the action.
See id. at 949-50. The agreement imposed dozens of require-
ments on Stimson’s use of its lands, all designed to promote
conservation of the grizzly bear. See id. Selkirk held it proper
for the FWS to consider the beneficial effects of the Conser-
vation Agreement in formulating its Biological Opinion,
while emphasizing that “federal agencies cannot delegate the
protection of the environment to public-private accords. Even
given the cooperation of private entities, the agencies must
vigilantly and independently enforce environmental laws.” Id.
at 955.

   As this admonition suggests, the conservation agreement in
Selkirk was, contrary to respondents’ assertion, enforceable
under the ESA: “The biological opinion incorporated the pro-
visions of the Conservation Agreement into the terms and
conditions of the Incidental Take Section, thus making Stim-
son’s compliance with the Agreement mandatory if Stimson
wishe[d] to avoid liability for the unauthorized taking of
endangered and threatened species.” Id. at 953 n.4. In addi-
           CENTER FOR BIOLOGICAL DIVERSITY v. BLM          12735
tion, all parties “implicitly assumed Stimson [was] contractu-
ally and legally bound to implement the agreed mitigation
measures and that the government agencies intend[ed] to
enforce Stimson’s compliance.” Id. at 954 n.5 (emphasis
added). We further articulated our “full[ ] expect[ation] that
Stimson and the government agencies [would] fulfill their
obligations” and noted that the plaintiff environmental group
was “undoubtedly committed to assuring that they do.” Id. As
previously noted, a citizen group is only empowered to
enforce such a public-private agreement if that agreement is
part of the project and so enforceable under the ESA, which
provides for citizen suits. See 16 U.S.C. § 1540(g).

   [3] We now hold what was implicit in Marsh and Selkirk
and is dictated by the statutory scheme: a conservation agree-
ment entered into by the action agency to mitigate the impact
of a contemplated action on listed species must be enforceable
under the ESA to factor into the FWS’s “biological opinion as
to whether [an] action, taken together with cumulative effects,
is likely to jeopardize the continued existence of listed species
or result in the destruction or adverse modification of critical
habitat.” 50 C.F.R. § 402.14(g)(4). Congress did not contem-
plate leaving the federal government’s protection of endan-
gered and threatened species to mechanisms other than those
specified by the ESA, the statute designed to accomplish that
protection. Rather, it entrusted the federal government’s pro-
tection of listed species and critical habitat to the Act’s own
provisions, and to the FWS, the agency with the expertise and
resources devoted to that purpose.

    c.   Categorizing the Conservation Action Plan
         measures

   Our question, then, is whether the CAP measures in this
case were properly categorized as background “cumulative
effects” or whether, instead, they should have been treated as
part of the proposed project, reviewed as such in the Biologi-
cal Opinion, and, if accepted as adequate, enforceable under
12736      CENTER FOR BIOLOGICAL DIVERSITY v. BLM
the ESA if not carried out. We conclude that the CAP—
entered into by FERC, the federal government action agency
—does not meet the criteria for background “cumulative
effects” and should only have been taken into account in the
Biological Opinion if incorporated as part of the proposed
project.

   Initially, the origin of the “cumulative effects” treatment of
the CAP measures is informative. At the outset, FWS and
FERC staff advocated for conflicting approaches toward the
CAP measures. While reviewing the September 2009 draft
Memorandum of Agreement, for example, the FWS’s section
7 Coordinator for the Project cautioned that “[i]f the voluntary
conservation actions are not part of Ruby/FERC’s proposed
action (and included in the [Biological Assessment] as such),
they cannot be analyzed in FWS’s determination of jeopar-
dy/adverse modification.” The Coordinator reemphasized this
concern a month later to colleagues at the FWS: “It needs to
be very clear that if Ruby/FERC truly want us to use the ESA
plan in our jeopardy analysis that it be included in the Biolog-
ical Assessment as part of the proposed action. And if that is
what they want — the actions will be required.” Despite these
and other admonitions, and notwithstanding the clear interre-
lation between the conservation activities and the pipeline
construction, FERC ultimately did not include the Conserva-
tion Action Plan measures in the proposed action.

   [4] Yet, the CAP measures and pipeline construction were
unequivocally interrelated, in that the promises regarding the
conservation measures were dependant on approval of the
project. This much is evident from Ruby’s Letter of Commit-
ment, which made clear that Ruby’s funding of the conserva-
tion measures was contingent upon FERC’s authorization of
the pipeline project: “Once Ruby has received a Certificate of
Public Convenience and Necessity . . . from FERC authoriz-
ing the Project and any legal challenges thereto have been
resolved such that Ruby may begin construction of the Proj-
ect, Ruby will fund the conservation actions described in the
           CENTER FOR BIOLOGICAL DIVERSITY v. BLM         12737
Plan.” In other words, the Conservation Action Plan projects
would not be implemented unless FERC green-lighted the
proposed action. See Marsh, 816 F.2d at 1387. This quid-pro-
quo relationship was underscored at oral argument when
counsel for the federal respondents characterized the Conser-
vation Action Plan measures as items on the FWS’s “wish
list.” The CAP measures were thus not “future non-federal
actions,” ESA Handbook at 4-32. Instead, their implementa-
tion depended on Federal authorizations.

   The CAP measures, moreover, fit squarely within the defi-
nition of “conservation measures” in the ESA Handbook.
They included projects designed to “benefit or promote the
recovery of,” ESA Handbook at xii, the same nine listed fish
species that the pipeline project would likely adversely affect.
As such, they were intended to “compensate for . . . project
effects on the species under review,” ESA Handbook at xii,
and were, moreover, “closely related to the action,” id. at 4-
19, as evidenced by their location within the Project’s action
area, as well as their potential to improve bodies of water
impacted by the Project.

   For example, the Project would result in “[i]ncreased sedi-
ment loads and water turbidity,” which could, among other
adverse effects, degrade spawning habitat, compromise juve-
nile fish survival, and “adversely affect fish behavior, such as
feeding and migration.” Corresponding closely to these
impacts, one of the Conservation Action Plan measures con-
sisted of improving an aging road adjacent to Thomas Creek,
the only habitat of the Modoc sucker. According to the CAP
description, “[r]educed sedimentation from road improvement
will benefit spawning and rearing habitats for the Modoc
sucker.” Thus, although language in the draft Memorandum
of Agreement stating that the Conservation Action Plan mea-
sures were “designed to offset potential adverse impacts to
listed species and critical habitat,” was removed, a compari-
son of the Biological Opinion and the CAP confirms that
those measures were intended to serve precisely that purpose.
12738      CENTER FOR BIOLOGICAL DIVERSITY v. BLM
That purpose is further confirmed by the Biological Opinion’s
reliance on the measures to conclude that there would be no
jeopardy to the nine listed species.

   “In short, we must determine whether an animal which
looks like a duck, walks like a duck, and quacks like a duck,
is in fact a duck.” In re Safeguard Self-Storage Trust, 2 F.3d
967, 970 (9th Cir. 1993). Labeling the Conservation Action
Plan measures as “private” and “voluntary” does not eliminate
their unequivocal relation to and dependence on the Project,
which the parties agree is a federal action. The federal nature
of the CAP measures is also apparent from their characteriza-
tion in the Letter of Commitment as “hav[ing] been extracted
from listed species recovery plans, other ESA action plans, or
recovery team activities”—that is, from activities authorized
by the FWS for the purpose of preserving the impacted listed
species. See 50 C.F.R. § 402.02.

   Moreover, Ruby’s financial commitments are partial, and if
the measures are not carried out, Ruby’s only obligation will
be working with the FWS and other entities to “identify”
other ESA conservation actions. Furthermore, the Letter cre-
ated no binding timeline for implementation of the Conserva-
tion Action Plan measures; it notes only that Ruby
“anticipates” that the actions will be “initiated within five
years of Ruby’s receipt of [the FERC] Certificate.”

   [5] Were these vague and distant-in-time measures consid-
ered in the Biological Opinion as part of the project in ques-
tion, it is quite possible that they would have been
disapproved as inadequate for ESA § 7 and § 9 purposes. Sev-
ering the Conservation Action Plan measures from the pro-
posed action and instead treating their anticipated benefits as
“cumulative effects” of independent origin insulated the
action agencies from consultation requirements under section
7, and Ruby from the ESA’s penalties for unlawful take under
section 9 in the event that the measures never materialized.
              CENTER FOR BIOLOGICAL DIVERSITY v. BLM                   12739
   [6] The Biological Opinion therefore unreasonably relied
on the Conservation Action Plan measures as “cumulative
effects” and took them into account in the jeopardy determi-
nation, when reliance on them would have been proper only
if they were included as part of the project and so subject to
the ESA’s consultation and enforcement provisions. As the
Opinion is therefore arbitrary and capricious, it must be set
aside.

B.     Withdrawals of groundwater

  Petitioners also contend that the Biological Opinion was
arbitrary and capricious because, in reaching incidental take
conclusions for listed fish species, it did not consider the
potential effects of withdrawing 337.8 million gallons of
groundwater from sixty-four wells along the length of the
pipeline. We agree.

  1.    Background

   Ruby proposed to withdraw water during the construction
phase of the pipeline project for two primary purposes: (1)
hydrostatic testing10 and (2) dust abatement.11 Although Ruby
proposed to use both groundwater and surface water for
hydrostatic testing and dust abatement, the Biological Opinion
discussed only the likely impacts of surface water withdraw-
als on listed fish species. It did not address what effects, if
any, the groundwater withdrawals would likely have.
  10
      Hydrostatic testing “involves filling the pipeline with water to a desig-
nated test pressure and maintaining that pressure for about 8 hours” to
determine whether the pipeline is capable of withstanding the operating
pressure for which it was designed.
   11
      Dust abatement involves using water to control dust produced during
various construction activities such as vegetation and topsoil removal,
blasting and trenching, and the movement of vehicles and motorized
equipment on unpaved access roads.
12740           CENTER FOR BIOLOGICAL DIVERSITY v. BLM
   Whether this omission was arbitrary and capricious
depends on whether information available to the FWS indi-
cated that the groundwater withdrawals “may affect” listed
species. 50 C.F.R. § 402.14(a). The ESA regulations required
the FWS to “[r]eview all relevant information provided by the
[action] agency or otherwise available” during the formal con-
sultation process. Id. § 402.14(g)(1). Both the Biological
Assessment and the Final Environmental Impact Statement,12
which were issued approximately six months before the Bio-
logical Opinion, were “relevant” and “available” within the
meaning of the regulations. Indeed, the FWS’s cover letter to
the Biological Opinion acknowledged that the Opinion was
“based on information gathered from multiple sources includ-
ing the Project’s Biological Assessment and Final Environ-
mental Impact Statement.” We summarize below the
information in the Biological Assessment, Biological Opin-
ion, and Final Environmental Impact Statement pertaining to
water withdrawals and their potential impacts on listed fish
species.
  12
     The National Environmental Policy Act (“NEPA”) requires agencies
to prepare a detailed environmental impact statement for all “major Fed-
eral actions significantly affecting the quality of the human environment.”
42 U.S.C. § 4332(C). The statement must discuss:
       (i) the environmental impact of the proposed action,
       (ii) any adverse environmental effects which cannot be avoided
       should the proposal be implemented,
       (iii) alternatives to the proposed action,
       (iv) the relationship between local short-term uses of man’s envi-
       ronment and the maintenance and enhancement of long-term pro-
       ductivity, and
       (v) any irreversible and irretrievable commitments of resources
       which would be involved in the proposed action should it be
       implemented.
Id.
              CENTER FOR BIOLOGICAL DIVERSITY v. BLM           12741
       a.   The Biological Assessment

   According to the Biological Assessment, “[w]ater for
hydrostatic testing would be obtained from a combination of
groundwater and surface waters.” Ruby would withdraw sur-
face water from the Colorado River system and groundwater
from sources in Nevada and Oregon. As to Lahontan cutthroat
trout, found in Oregon and Nevada, the Biological Assess-
ment explained that “because no surface waterbodies in
Nevada would be used for hydrostatic testing or dust control,
no cumulative water depletions would impact the population
status or recovery of this species.”13 (Emphasis added.) As to
the various listed suckers also found in Oregon and Nevada,
the Biological Assessment reasoned that because no surface
waters containing any of the listed suckers would be used for
hydrostatic testing, “no cumulative water depletions would
impact the population status or recovery of these species.”
The Biological Assessment did not discuss whether Ruby’s
withdrawals of groundwater in Nevada and Oregon would
likely affect the Lahontan cutthroat trout or listed suckers.

       b.   Biological Opinion

   Consistent with the Biological Assessment, the Biological
Opinion mentioned Ruby’s plans to withdraw both groundwa-
ter and surface water for hydrostatic testing. It specified that
Ruby would withdraw surface water from the Colorado River
Basin, but that “[a]ll other waters for hydrostatic testing in
listed fish basins will be removed from below-surface wells.”
The Biological Opinion concluded that the surface water
depletions would have “a minor, but still adverse, effect on
Colorado River fishes,” but did not discuss what effect, if any,
groundwater withdrawals would likely have on the five listed
fish species in the project’s action areas outside the Colorado
River Basin.
  13
    The Biological Assessment defines a water “depletion” as “consump-
tive loss plus evaporative loss of surface or groundwater within the
affected basin.”
12742      CENTER FOR BIOLOGICAL DIVERSITY v. BLM
    c.   Final Environmental Impact Statement

   The Final Environmental Impact Statement provided more
detailed information about Ruby’s proposed water withdraw-
als. It indicated that Ruby planned to withdraw nearly 338
million gallons of groundwater along the length of the pipe-
line in Wyoming, Utah, Nevada, and Oregon. In contrast,
much smaller quantities of surface waters would be used; only
29 million gallons would be used for hydrostatic testing, and
only 35 million gallons would be used for dust abatement.
Groundwater was to be drawn from sixty-four different wells
in varying quantities, while surface water was to be drawn
from twenty-one sources, all within the Colorado River Basin.

   The Final Environmental Impact Statement discussed in
great detail the anticipated impact of taking surface water
from three of these sources, explaining that the withdrawals
could result in the temporary loss of habitat, change water
temperatures and dissolved oxygen levels, increase down-
stream flows, and contribute to streambank and substrate
scour. The Statement noted that the withdrawal of 16 million
gallons of surface water “represents a substantial quantity of
water that may contribute to depletion effects to Colorado
River Basin listed fishes,” and concluded that the project “is
likely to adversely affect” those fishes.

   In contrast to its detailed analysis of surface water with-
drawal impacts, the Statement provided a much more limited
discussion of the likely effects of Ruby’s proposed groundwa-
ter withdrawals:

       We received numerous comments expressing con-
    cern that appropriation of groundwater for hydro-
    static testing and dust control could cause
    detrimental effects to the area’s limited water
    resources. Our review of data published by the
    National Drought Mitigation Center has revealed
    that portions of Wyoming, Utah, Nevada, and south-
             CENTER FOR BIOLOGICAL DIVERSITY v. BLM        12743
       ern Oregon are currently experiencing drought con-
       ditions. Therefore, the use of groundwater for
       construction purposes has the potential to impact the
       already limited water supply in these areas. . . .

          The volumes of groundwater to be appropriated
       for hydrostatic testing and dust abatement are esti-
       mated at 338 million gallons, which is substantially
       more than the 66 million gallons originally identified
       by Ruby and evaluated in the draft EIS. Because the
       volume of water is considerable and the project is
       located in a region of the country where water
       resources are limited, we believe that appropriating
       water of this volume could result in a significant
       impact.

The Final Environmental Impact Statement did not specify,
however, whether that “significant impact” was likely to
include effects on listed fish species, even though the Proj-
ect’s action area in Nevada and Oregon, where the groundwa-
ter withdrawals were to occur, encompassed potential critical
habitat for Lahontan cutthroat trout and listed suckers.

  2.     Discussion

   A Biological Opinion is arbitrary and capricious if it fails
to “consider[ ] the relevant factors and articulate[ ] a rational
connection between the facts found and the choice made.’ ”
Pac. Coast Fed’n of Fishermen’s Ass’ns, 265 F.3d at 1034
(quoting Natural Res. Def. Council v. U.S. Dep’t of the Inte-
rior, 113 F.3d 1121, 1124 (9th Cir. 1997)). The parties dis-
agree as to whether groundwater withdrawals constituted a
“relevant factor” in determining whether the project would
likely jeopardize the continued existence of any listed fish
species or result in the destruction or adverse modification of
their habitat. Id.

   To determine whether the groundwater withdrawals were a
“relevant factor” that should have been analyzed in the Bio-
12744      CENTER FOR BIOLOGICAL DIVERSITY v. BLM
logical Opinion, we begin with the ESA regulations. Section
402.14 of those regulations states that “[e]ach federal agency
shall review its actions at the earliest possible time to deter-
mine whether any action may affect listed species or critical
habitat.” 50 C.F.R. § 402.14(a) (emphasis added). Where
actions “may affect” listed species, “the burden is on the Fed-
eral agency to show the absence of likely, adverse effects to
listed species or critical habitat as a result of its proposed
action in order to be excepted from the formal consultation
obligation.” 51 Fed. Reg. 19926, 19949 (June 3, 1986). Other-
wise, formal consultation must proceed, and the FWS must
formulate a Biological Opinion that, among other things,
includes “[a] detailed discussion of the effects of the action on
listed species or critical habitat.” 50 C.F.R. § 402.14(h)(2).

   We have previously held that the “ ‘may affect’ standard
‘must be set sufficiently low to allow Federal agencies to sat-
isfy their duty to insure under section 7(a)(2) [that species are
not jeopardized].’ ” Flowers, 414 F.3d at 1072 (quoting 51
Fed. Reg. at 19949) (internal quotation marks omitted) (alter-
ation in original). “Any possible effect, whether beneficial,
benign, adverse, or of an undetermined character, triggers the
formal consultation requirement.” Id. (internal quotation
marks omitted) (emphasis in original); accord Cal. Wilder-
ness Coal. v. U.S. Dep’t of Energy, 631 F.3d 1072, 1106 (9th
Cir. 2011). Thus, while petitioners bear the burden of showing
that the groundwater withdrawals “may affect” listed species
or critical habitat, the burden is not a heavy one. Essentially,
petitioners need to show only that an effect on listed species
or critical habitat is plausible.

   The government first argues that groundwater withdrawals
would have no discernible impact on listed fish species
because “[t]hose species do not live in ground water—they
live in rivers and streams.” That explanation is specious.
Obviously, fish do not live underground. But, as the govern-
ment recognizes, “groundwater and surface water are ‘physi-
cally interrelated as integral parts of the hydrologic cycle.’ ”
           CENTER FOR BIOLOGICAL DIVERSITY v. BLM        12745
Indeed, “[i]n most areas, the surface- and ground-water sys-
tems are intimately linked,” U.S. Geological Survey, U.S.
Dep’t of the Interior, Fact Sheet No. 103-03, Ground-Water
Depletion Across the Nation 2 (2003), and withdrawing
groundwater from nearby surface waters “can diminish the
available surface-water supply by capturing some of the
ground-water flow that otherwise would have discharged to
surface water,” Thomas C. Winter et al., U.S. Geological Sur-
vey, U.S. Dep’t of the Interior, Circular No. 1139, Ground
Water and Surface Water: A Single Resource 12 (1998). In
Cappaert v. United States, 426 U.S. 128, 142 (1976), for
example, the petitioner’s pumping of groundwater was caus-
ing the water level of a nearby pool of surface water to
decrease. See also United States v. Smith, 625 F.2d 278, 280
(9th Cir. 1980) (observing that pumping groundwater may
affect flow of nearby river). As the U.S. Geological Survey
has explained:

    Ground-water pumping can alter how water moves
    between an aquifer and a stream, lake, or wetland by
    either intercepting ground-water flow that discharges
    into the surface-water body under natural conditions,
    or by increasing the rate of water movement from
    the surface-water body into an aquifer. In either case,
    the net result is a reduction of flow to surface water
    ....

Fact Sheet No. 103-03 at 2; see also Leonard F. Konikow &
Eloise Kendy, Groundwater Depletion: A Global Problem, 13
Hydrogeology J. 317, 317 (2005) (describing how “lowered
water tables” resulting from groundwater withdrawal may
“reduce groundwater discharge to springs, streams, and wet-
lands”); Marios Sophocleous, Interactions Between Ground-
water & Surface Water: The State of the Science, 10
Hydrogeology J. 52, 60-63 (2002) (explaining that excessive
12746        CENTER FOR BIOLOGICAL DIVERSITY v. BLM
pumping of groundwater can cause significant surface-water
depletion).14

   Accordingly, depletion in underlying groundwater levels
could conceivably alter surface water levels. Changes in sur-
face water levels may, in turn, affect listed species, for all the
reasons explained in detail in the Final Environmental Impact
Statement.

   [7] In several respects, the record supports this hypothesis
regarding the possible impact of ground water withdrawal on
surface water levels and therefore on listed species as one suf-
ficiently plausible that the Biological Opinion should have
addressed it. First, the Biological Opinion itself indicated that
the Project would cross numerous surface waterways that fell
within or linked to designated or potential critical habitat, and
that Ruby proposed to withdraw significant amounts of
groundwater from some of these areas. Next, the Final Envi-
ronmental Impact Statement explained that the Project’s
action area extended over the Basin and Range aquifer sys-
tem, a repository of groundwater that underlies the Project’s
action area in Nevada and southern Oregon. Significantly, the
Final Environmental Impact Statement asserted that “[a]quifer
discharge” within this system “occurs through upward leak-
age to shallower aquifers and then the major streams.” The
Final Environmental Impact Statement thus established that at
least some surface waters within this region are connected to
underlying groundwater, and so suggests that decreases in
groundwater levels could lead to corresponding decreases in
surface water levels. The record thus demonstrates that
groundwater withdrawals were a “relevant factor” that should
have been considered in the Biological Opinion, even though
  14
    A reviewing court may look beyond the administrative record “for the
limited purposes of ascertaining whether the agency considered all the rel-
evant factors or fully explicated its course of conduct or grounds of deci-
sion.” Asarco, Inc. v. EPA, 616 F.2d 1153, 1160 (9th Cir. 1980). It is for
that purpose that we do so here.
           CENTER FOR BIOLOGICAL DIVERSITY v. BLM        12747
groundwater sources do not themselves provide habitat for
listed fish.

   Anticipating this conclusion, the government alternatively
argues that “the groundwater depletions contemplated by this
Project are simply too small to have any discernible effect on
the surface water flows to which they are connected.” Assert-
ing that “the relationship of groundwater flows to surface
water flows is not one-to-one,” the government maintains that
“[a]lthough 337.8 million gallons of groundwater depletion
might sound significant to those outside the field, in the con-
text of ESA consultation it is not, when the depletion will
occur as a one-season event spread between 6[4] separate
locations along the Pipeline route . . . .”

   The record, however, indicates that this assertion is not
self-evident even to those not “outside the field.” The Final
Environmental Impact Statement noted that “[t]he use of . . .
groundwater for hydrostatic testing, dust abatement, and vehi-
cle washing could directly or indirectly affect surface water
volumes.” (Emphasis added.) It also characterizes the volume
of groundwater to be withdrawn as “considerable,” especially
considering that “the project is located in a region of the
country where water resources are limited.” In addition, a
draft of the Biological Assessment revealed comments by
FWS staff advocating the “use of high pressure air in place of
water to test the pipeline in order to avoid adverse effects to
LCT [Lahontan cutthroat trout] through water depletion from
both surface and groundwater sources” (Emphasis added.)
Moreover, contrary to the government’s intimation that the
groundwater withdrawals were individually small, over 40
million gallons of groundwater was to be withdrawn from a
single source. In comparison, the largest withdrawal of sur-
face water from any single source would amount to just over
16 million gallons. The record therefore provides a basis for
inferring that even if surface water levels do not vary on a
one-to-one ratio in response to fluctuating groundwater levels,
the groundwater withdrawals at the level contemplated are
12748      CENTER FOR BIOLOGICAL DIVERSITY v. BLM
not, as the government now maintains, de minimis, and so
“may affect” listed fish species.

   It is of course possible, as the government argues, that the
groundwater withdrawals would ultimately have had no “dis-
cernible effect” on listed fish. But it is also plausible that
groundwater depletions in Nevada and Oregon would have
adversely affected Lahontan cutthroat trout and the listed
suckers, especially in light of the conclusion in both the Bio-
logical Assessment and the Final Environmental Impact State-
ment that “[a]ny water depletion would represent an adverse
impact on habitat” (emphasis added) for other listed fish
within the project’s action areas (i.e., the Colorado River
Basin species). While the record certainly does not compel
either conclusion, it does establish that the groundwater with-
drawals were a “relevant factor” that required discussion in
the Biological Opinion. See Pac. Coast Fed’n of Fishermen’s
Ass’ns, 265 F.3d at 1034.

   The Biological Opinion provides no indication at all that
FWS applied its expertise to the question of whether ground-
water withdrawals may adversely affect listed fish species.
“We cannot gloss over the absence of a cogent explanation by
the agency by relying on the post hoc rationalizations offered
by defendants in their appellate briefs.” Humane Soc’y of U.S.
v. Locke, 626 F.3d 1040, 1049 (9th Cir. 2010). Moreover,
given the surface inadequacy of those explanations,
“[d]efendants’ post hoc explanations serve only to underscore
the absence of an adequate explanation in the administrative
record itself. “ Id. at 1050.

   [8] In sum, groundwater withdrawals constituted a “rele-
vant factor” to determining whether the Project would result
in jeopardy to listed fish species or adverse modification of
those species’ critical habitat. See Pac. Coast Fed’n of Fisher-
men’s Ass’ns, 265 F.3d at 1034. The FWS therefore acted
unreasonably when it did not discuss the potential impacts of
groundwater withdrawals on the listed species occupying the
            CENTER FOR BIOLOGICAL DIVERSITY v. BLM         12749
Project’s action areas in Nevada and Oregon, or, alternatively,
explain why the withdrawals would not likely have such
impacts. The Biological Opinion was therefore arbitrary and
capricious in failing to “examine the relevant data and articu-
late a satisfactory explanation for its action including a ‘ratio-
nal connection between the facts found and the choice
made’ ” in remaining silent on the potential impact of the
Project’s proposed groundwater withdrawals. See Motor Vehi-
cle Mfrs. Ass’n, 463 U.S. at 43 (quoting Burlington Truck
Lines v. United States, 371 U.S. 156, 168 (1962)); see also
Allen, 476 F.3d at 1041.

C.     Reliance on the 2004 Biological Opinion

   We next consider whether the Biological Opinion arbitrar-
ily and capriciously relied on an earlier biological opinion
when calculating incidental fish take levels associated with
using a “dry-ditch construction method” to cross bodies of
water. The FWS’s reliance on that opinion, we conclude, was
reasonable.

  1.    Background

   The Biological Opinion for the project stated that Ruby
would use the “dry ditch” method to cross bodies of water
providing, or connecting to, habitat for listed fish species.
This method entails installing a temporary dam on a body of
water and diverting the entire flow over the construction area
through a pipe or a pump. The work area between the dams
is emptied of water, and fish trapped in that area are captured
and released downstream by experienced fisheries biologists.
According to the Biological Opinion, this approach would
result in take of fish species in two ways. First, some fish
would remain “trapped between the upstream and down-
stream dams of the water body crossing” where, if missed
during salvage operations, they would “suffer harm or mortal-
ity during water body crossing construction.” Second, there
would be “[a]dverse, direct effects” on fish that are caught,
12750       CENTER FOR BIOLOGICAL DIVERSITY v. BLM
including “physical injury, death, and physiological stress
during capture, holding or release; predation and cannibalism
when relocated fish are released; and potential horizontal
transmission of disease and pathogens and stress-related phe-
nomena.”

   In estimating how many fish would be killed or injured
through this process, FWS relied on estimates from a 2004
biological opinion concerning an entirely separate project and
analyzing the impacts on shortnose suckers from the direct
handling and dewatering associated with certain “inwater con-
struction activities.” The 2004 opinion estimated that, for each
project, one fish would be killed from direct handling and one
would be killed during the dewatering procedure. The current
Biological Opinion adopted those estimates even though it
mandated a somewhat different “fish salvage sequence” than
the one postulated for the 2004 project.

  2.    Discussion

   The Incidental Take Statement accompanying the current
Biological Opinion, petitioners note, did not, unlike the 2004
document, require (1) slowly dewatering project areas so that
fish biologists could locate and remove trapped fish before
they were injured; and (2) isolating project areas to prevent
additional fish from entering. Petitioners assert that given
these differences, Ruby’s projected “dry-ditch” method could
result in a higher rate of take than that set forth in the 2004
opinion, and the FWS was therefore arbitrary and capricious
in relying on the earlier opinion. We do not agree.

   Contrary to the petitioners’ assertions, the current Biologi-
cal Opinion and Incidental Take Statement did require imple-
mentation of similar protective measures to those taken into
account in the 2004 opinion. First, the Biological Opinion
stated that water would be pumped out of project areas at
speeds that comported with Oregon Department of Fish and
Wildlife and Nevada Department of Wildlife standards, stan-
           CENTER FOR BIOLOGICAL DIVERSITY v. BLM         12751
dards petitioners regard as sufficiently protective. Compare
Pet’r Summit Lake’s Reply Br. 33 (discussing the “need for
a velocity requirement of 0.4 cubic feet per second for active
pump screens”), with Or. Dep’t of Fish and Wildlife,
Fish Screening Program: Small Pump Screen Self
Certification, available at ftp://ftp.odot.state.or.us/techserv/
Geo-Environmental/Biology/Biology_Manual/ODFW_Small
_Pump_Screen_Self_Certification_2004. pdf (providing that
“[t]he screen approach velocity for active pump screens shall
not exceed 0.4 fps (feet per second)”). By requiring Ruby to
adopt pump velocities at least as slow as those set forth by the
state agencies, Term 1.1(d) of the Incidental Take Statement
provided protections during the dewatering process equivalent
to those mandated by the 2004 Biological Opinion.

   Second, Terms 1.1(a) and (c) of the Incidental Take State-
ment together required that Project work sites in waterbody
crossings be isolated so that no additional fish could enter
after qualified biologists removed fish from the work site
area. Term 1.1(a) required Ruby to install “block nets” around
the areas where “coffer dam[s]” were to be placed, and Term
1.1(c) required that the nets be kept in place “during subse-
quent placement of [the] coffer dams.” Term 1.1(e) further
required that the biologists conduct a second “salvage pass”
of the isolated work area to capture and remove any additional
fish before it was completely dewatered.

   [9] Petitioners do not present any other objections to
FWS’s reliance on the 2004 biological opinion. We therefore
hold that the agency did not act arbitrarily and capriciously in
relying on the older biological opinion to estimate incidental
fish take levels associated with the “dry-ditch” construction
method.

D.   Quantifying the incidental take of Lahontan
     cutthroat trout eggs and fry

  Petitioners also contend that the Biological Opinion for
Ruby’s pipeline project was arbitrary and capricious for
12752       CENTER FOR BIOLOGICAL DIVERSITY v. BLM
another reason: its Incidental Take Statement authorized the
incidental take of “all eggs and fry” of threatened Lahontan
cutthroat trout near eighteen water crossings, without numeri-
cally limiting the take or explaining why doing so would be
impracticable. We conclude that the impracticability was self-
evident under the circumstances here, so no explanation was
needed. We also hold that the FWS’s alternative method of
defining the incidental take level was not arbitrary and capri-
cious.

  1.    Background

   Lahontan cutthroat trout begin to spawn in April but, in
colder, higher elevation waters, may spawn as late as July.
Where the trout might be present, the Biological Opinion for-
bade Ruby from undertaking inwater work before July 1, the
date by which most young fish would have emerged from the
spawning gravel. The Opinion recognized, however, that an
unknown number of eggs and fry “may still be in the gravel”
at a “limited number of higher elevation” water crossings
after July 1. The Incidental Take Statement therefore autho-
rized the take, after July 1, of “all eggs and fry” of Lahontan
cutthroat trout at eighteen water crossings. Specifically, (1) as
to incidental takings in the form of mortality arising from
“fish salvage” procedures associated with water crossings, the
Statement allowed the take, after July 1, of “[a]ll eggs and fry
within 10 higher-elevation waterbody crossings,” provided
that “[m]ortality per stream [would be] limited to the 115 ft
wide work area”; and (2) as to incidental takes arising from
blasting, the Statement permitted the take, after July 1, of
“[a]ll eggs and fry within and adjacent to 8 higher-elevation
waterbody crossings,” provided that “[m]ortality [would be]
limited to areas 200 feet upstream and downstream from the
isolated work area.”

  2.    Discussion

  An Incidental Take Statement that “contains no numerical
cap on take and fails to explain why it does not” normally vio-
           CENTER FOR BIOLOGICAL DIVERSITY v. BLM          12753
lates the ESA. Allen, 476 F.3d at 1037. Similarly, while an
Incidental Take Statement may use “a surrogate” to delimit
incidental take levels where “no number may be practically
obtained,” id. at 1038, the statement ordinarily “must explain
why it was impracticable to express a numerical measure of
take,” id. at 1037.

   [10] The Incidental Take Statement for the Project did not
explain its failure to quantify the authorized take of Lahontan
cutthroat trout eggs and fry. But the impracticability of quan-
tifying this take is self-evident, in light of the very large num-
ber and minute size of fish eggs and fry. Notably, when
“Congress recognized . . . that a numerical value would not
always be available” in delimiting incidental take levels under
the ESA, it provided as an example “ ‘the number of eggs of
an endangered or threatened fish which will be sucked into a
power plant when water is used as a cooling mechanism.’ ”
Id. (quoting H.R. Rep. No. 97-567, at 27 (1982), reprinted in
1982 U.S.C.C.A.N. 2807, 2827). Given the highly analogous
situation here, the Incidental Take Statement did not need to
explain why “ ‘no such numerical value could be practically
obtained.’ ” Id. (quoting Ariz. Cattle Growers’ Ass’n, 273
F.3d at 1250). This case thus contrasts with Allen, in which
we held that the FWS had unreasonably failed to explain why
it could not “numerically . . . quantify the level of take of
northern spotted owls,” id. at 1038, given the evident practica-
bility of doing so.

   Furthermore, the Incidental Take Statement did not ignore
the incidental take issue, but instead used a surrogate for
determining incidental take levels. We have previously
observed that “various components of the ecological land-
scape . . . [can] be used as a surrogate for defining the amount
or extent of take if the conditions [are] linked to the take of
the protected species.” Id. at 1038. For the chosen surrogate
to be reasonable, it “must be able to perform the functions of
a numerical limitation.” Id.
12754      CENTER FOR BIOLOGICAL DIVERSITY v. BLM
   [11] Consistent with these principles, the Incidental Take
Statement permissibly used “habitat characteristics” as a
proxy for a numerical limit. See id. It restricted the incidental
take from “salvage” activities to eggs and fry to “the 115 ft
wide work area” of “10 higher-elevation waterbody cross-
ings.” Similarly, it limited the take of eggs and fry from blast-
ing activity to those within or adjacent to “8 higher-elevation
waterbody crossings,” so long as “[m]ortality [was] limited to
areas 200 feet upstream and downstream from the isolated
work area.” Both types of work were not to begin until July
1st. Because these proxies, in the form of narrowly drawn
geographical areas, “set a clear standard for determining when
the authorized level of take had been exceeded,” id. at 1039,
the Incidental Take Statement was not arbitrary and capri-
cious in its methods of quantifying the incidental take of
Lahontan cutthroat trout eggs and fry.

E.   The BLM’s reliance on the Biological Opinion

   Finally, the petitioners maintain that the BLM’s Record of
Decision must be set aside because it relied on the FWS’s
flawed Biological Opinion. Section 7 of the ESA imposes a
substantive duty on the BLM to ensure that its actions are not
likely to jeopardize the continued existence of the listed fish
or result in destruction or adverse modification of critical hab-
itat. See 16 U.S.C. § 1546(a)(2). “ ‘Arbitrarily and capri-
ciously relying on a faulty Biological Opinion violates this
duty.’ ” Wild Fish Conservancy v. Salazar, 628 F.3d 513, 532
(9th Cir. 2010) (quoting Defenders of Wildlife v. EPA, 420
F.3d at 976). In particular, an agency cannot meet its section
7 obligations by relying on a Biological Opinion that is
legally flawed or by failing to discuss information that would
undercut the opinion’s conclusions. See id.

   [12] The Biological Opinion here was both legally flawed
—because it relied in large part on the beneficial effects of the
Conservation Action Plan measures as “cumulative effects” to
reach its “no jeopardy” and “no adverse modification”
           CENTER FOR BIOLOGICAL DIVERSITY v. BLM         12755
determinations—and inadequate with regard to evaluating the
potential impacts of the Project’s groundwater withdrawals.
Accordingly, the BLM violated its substantive duty to ensure
that its authorization of the Project would not jeopardize the
survival of the nine listed fish or adversely modify the spe-
cies’ critical habitat.

                              ***

   [13] For the foregoing reasons, we vacate the FWS’s Bio-
logical Opinion and remand for the agency to formulate a
revised Biological Opinion that: (1) addresses the impacts, if
any, of Ruby’s groundwater withdrawals on listed fish species
and critical habitat; and (2) categorizes and treats the Conser-
vation Action Plan measures as “interrelated actions” or
excludes any reliance on their beneficial effects in making a
revised jeopardy and adverse modification. We otherwise
deny the petition as to the issues discussed in this opinion. We
also vacate and remand the BLM’s Record of Decision.

  VACATED AND REMANDED.
