United States Court of Appeals
                               FOR THE EIGHTH CIRCUIT
                                         ___________

                                         No. 07-1149
                                         ___________

In re: Operation of the Missouri              *
        River System Litigation.              *
------------------------------------------------
                                              *
State of Missouri,                            *
                                              *
       Plaintiff - Appellant,                 * Appeal from the United States
                                              * District Court for the
       v.                                     * District of Minnesota.
                                              *
United States Army Corps of                   *
Engineers, et al.,                            *
                                              *
       Defendants - Appellees.                *
                                         ___________

                                  Submitted: October 5, 2007
                                      Filed: February 8, 2008
                                      ___________

Before LOKEN, Chief Judge, RILEY and SMITH, Circuit Judges.
                              ___________

LOKEN, Chief Judge.

      The United States Army Corps of Engineers (“Corps”) manages the Missouri
River Mainstem Reservoir System (the “System”) under the Flood Control Act of
1944, Pub. L. No. 78-534, 58 Stat. 887, 891 (1944). The System consists primarily
of a series of dams and reservoirs on the upper River. The Corps’ governing
operational document is the Missouri River Mainstem Reservoir Master Water
Control Manual (the “Master Manual”), which has been revised five times since its
initial adoption in 1960. The Corps also publishes specific operational details in an
Annual Operating Plan.

       In recent years, persistent drought conditions have challenged the Corps’ ability
to perform its dominant Flood Control Act functions of flood control and maintaining
downstream navigation while also continuing to benefit secondary uses such as
irrigation, recreation, fish, and wildlife. Forced to make difficult choices, the Corps
has faced repeated lawsuits by competing beneficial users of the River as controlled
by the System. In South Dakota v. Ubbelhode, 

 (8th Cir. 2003), cert.
denied, 

 (2004), we reversed the grant of preliminary injunctions
preventing the Corps from releasing drought-depleted waters from reservoir lakes in
South Dakota and North Dakota in order to maintain downstream navigation.
Meanwhile, environmental groups sued, and the Judicial Panel on Multi-District
Litigation consolidated all actions in the District of Minnesota. In March 2004, the
Corps issued a revised Master Manual (“the 2004 Master Manual”) containing
provisions prompted by a Biological Opinion issued by the U.S. Fish and Wildlife
Service (“FWS”) under the Endangered Species Act. See 16 U.S.C. § 1536.
Competing users challenged the actions of both agencies on numerous grounds. In In
re Operation of the Missouri River System Litigation, 

 (8th Cir. 2005),
cert. denied, 

 (2006) (hereinafter “Mo. River”), we affirmed the district
court’s grant of summary judgment in favor of both agencies.

       In this action, a sequel to Mo. River, the State of Missouri claims that the Corps
violated the National Environmental Policy Act (“NEPA”) by implementing March
2006 revisions to the 2004 Master Manual without preparing a supplemental
environmental impact statement (“SEIS”). The district court1 granted the Corps’
motion for summary judgment. Missouri appeals. We conclude that the Corps’
actions were not arbitrary and capricious and therefore affirm.


      1
       The HONORABLE PAUL A. MAGNUSON, United States District Judge for
the District of Minnesota.
                              -2-
                                            I.

       Acting under the Endangered Species Act, FWS listed the least tern2 as
endangered and the piping plover as threatened in 1985 and the pallid sturgeon3 as
endangered in 1990. In developing the 2004 Master Manual, the Corps consulted
FWS after both agencies determined that operation of the System jeopardizes these
protected species. In 2000, FWS issued a Biological Opinion (“BiOp”) that included
a Reasonable and Prudent Alternative (“RPA”)4 recommending various actions by the
Corps to mimic the natural hydrograph of the River to benefit the listed species. See
Mo. River, 421 F.3d at 625-26. A key recommendation was a “spring rise” -- a
controlled release of additional water from the Gavins Point Dam for thirty days every
three years. The BiOp explained that the spring rise would act as a spawning cue for
pallid sturgeon, provide an influx of nutrients from the floodplain for all three species,
and scour sandbars to allow terns and plovers to nest more safely.

       In the Final Environmental Impact Statement (“FEIS”) for the 2004 Master
Manual, the Corps analyzed the projected economic and environmental effects of five
alternatives to the then-current water control plan -- four spring rise/summer low flow
release options from the Gavins Point Dam based upon the FWS RPA, and a Modified
Conservation Plan that did not include a spring rise but instead focused on drought
conservation measures, reservoir balancing, minimum water flows, and


      2
        A subspecies, Sternula antillarum athalassos, that breeds solely on the inland
rivers of the Mississippi River basin.
      3
        The Pallid Sturgeon first evolved seventy million years ago and ranges from
the Yellowstone River in Montana throughout the Missouri River and into the lower
Mississippi River. The pallid sturgeon grows up to eighty pounds, reaches six feet in
length, and lives an average of sixty years. Changes made by the Corps to the natural
hydrograph of the Missouri River have caused a precipitous drop in natural sturgeon
reproduction, particularly on the lower River below Gavins Point Dam.
      4
       See 16 U.S.C. § 1536(b)(3)(A).
                                           -3-
implementation of an adaptive management process to give the Corps flexibility to
adjust the System. The FEIS chose the Modified Conservation Plan as its Preferred
Alternative but noted that the absence of a spring rise may result in “jeopardy of the
three listed species” and non-compliance with the Endangered Species Act.

       After reviewing the FEIS and consulting with the Corps, FWS issued an
amended BiOp in November 2003 (the “2003 Amended BiOp”) that gave the Corps
two more years to develop an acceptable alternative to the spring rise. If no
alternative was developed, the FWS amended RPA imposed a default plan including
a spring rise beginning in 2006 for the benefit of the endangered pallid sturgeon. The
default plan prescribed an annual “bimodal” spring rise, with releases from the Gavins
Point Dam in both March and May. In March 2004, the Corps adopted the 2004
Master Manual including the Modified Conservation Plan. The agency’s Record of
Decision (“ROD”) acknowledged a continuing obligation to evaluate a spring rise as
mandated by the 2003 Amended BiOp. The ROD declared:

      Decisions concerning implementation of additional measures . . .
      including potential release changes out of Gavins Point Dam, will be
      made through the adaptive management process. The two-year re-
      evaluation will include input from Missouri River stakeholders to foster
      conservation of Endangered Species Act-listed species and the broader
      ecosystem values of the Missouri River while providing other
      Congressionally authorized System project purposes.

In Mo. River, rejecting multiple attacks on the 2004 Master Manual based on the
Flood Control Act, the Endangered Species Act, and NEPA, we described the 2004
Modified Conservation Plan as “a plan consistent with the 2003 Amended BiOp.”
421 F.3d at 627.

      Following adoption of the 2004 Master Manual, the Corps formed a Plenary
Group of numerous Missouri Basin stakeholders, including the Missouri Department
of Natural Resources, to develop a recommendation on the spring rise issue. The
                                         -4-
Plenary Group met four times in the summer of 2005. Though unable to reach a
consensus, the Group provided input and technical assistance. In October, the Corps
released for review and comment a draft Annual Operating Plan and draft technical
criteria for a Spring Pulse Water Control Plan. Like the FWS amended RPA, the Plan
includes a bimodal spring rise -- annual releases from the Gavins Point Dam in March
and in May. Both the March pulse and the May pulse are precluded if the reservoir
system is not storing at least 36.5 million acre feet of water in the first year and 40
million acre feet in any subsequent year. If not precluded, the March pulse begins the
day after the flow out of Gavins Point Dam reaches the minimum level necessary for
downstream navigation. The pulse consists of a two-day peak release of up to 5,000
cubic feet per second in addition to the existing flow, followed by gradually reduced
releases for five days until the flow is reduced to the non-pulse downstream flow
level. The May pulse begins between May 1 and May 19, depending upon water
temperatures, and increases by approximately 6,000 cubic feet per second per day
until the two-day peak is achieved. The peak varies depending upon factors such as
system storage, downstream flow limits, and the risk a release will “take” threatened
or endangered species. The pulse is then reduced over ten days to the non-pulse
downstream flow level.

       Following public meetings and a two-month public comment period, the Corps
prepared an EA comparing the impacts of the proposed bimodal spring rise plan, the
default bimodal spring rise plan in the FWS 2003 Amended BiOp, the spring rise
alternatives analyzed in the 2004 FEIS, the pre-2004 water control plan, and the
Modified Conservation Plan adopted in the 2004 Master Manual. The EA calculated
the benefits provided by each plan measured by fifteen different criteria.5 It reported


      5
       Flood control, hydropower, water supply, recreation, navigation, national
economic development, young-of-year reservoir fish production, reservoir coldwater
fish habitat, river coldwater fish habitat, river warmwater fish habitat, riverine native
fish physical habitat, riverine tern and plover habitat, wetland habitat, riparian habitat,
and historic and cultural properties.
                                            -5-
that the impacts of the proposed bimodal spring rise plan “are within the range of
impacts of the alternatives considered in [the] FEIS that contained spring pulse
releases.” The EA also compared the proposed bimodal spring rise plan with water
release data from the operation of the System since its inception in 1967, concluding
that the proposed peak releases “are well within the normal operating range of Gavins
Point Dam” and significantly lower than the historical maximum daily release rates
set in 1997. Analyzing historical flood damage data, the EA also reported that,
because of downstream flow limits and other flood control measures, the proposed
spring rise plan would rarely, if ever, result in increased flooding and crop damages
beyond what would occur without a spring rise.

       Based upon this analysis, the EA concluded “that there are no new significant
environmental impacts of the proposed action that have not been evaluated in the FEIS
and that warrant the preparation of a Supplement to the Final Environmental Impact
Statement prior to implementation of the proposed action.” In March 2006, the Corps
issued an ROD revising the 2004 Master Manual to include the bimodal spring rise
plan. Missouri, which has consistently opposed a spring rise because of its potential
adverse effect on downstream flood control, commenced this action to enjoin
implementation of the spring rise plan. The district court granted the Corps’ motion
for summary judgment, concluding that the Corps did not violate NEPA when it
prepared an EA but then declined to prepare either an SEIS or a finding of no
significant impact (“FONSI”). This appeal followed. Because drought conditions
have persisted, only one spring rise release has occurred, in May 2006.

                                         II.

      Missouri’s primary contention is that the 2006 Master Manual revision was a
major federal action significantly affecting the human environment, and therefore the
Corps violated NEPA by failing to prepare an EIS or an SEIS. See 42 U.S.C.
§ 4332(2)(C). The Corps spent over fourteen years preparing the 2004 FEIS which
included a comprehensive environmental analysis of various spring rise plans. Thus,
                                           -6-
like the district court, we conclude that the relevant issue is whether the Corps was
required to prepare an SEIS. Our review is governed by the Administrative Procedure
Act’s arbitrary and capricious standard. See 5 U.S.C. § 706(2)(A); Marsh v. Oregon
Natural Resources Council, 

, 375-76 (1989). “We are not free to
substitute our own judgment for that of the agency, but rather our role is to ensure that
the agency has adequately considered and disclosed the environmental impacts of its
actions.” Arkansas Wildlife Fed’n v. U.S. Army Corps of Eng’rs, 

,
1100 (8th Cir. 2005) (quotations omitted).

     NEPA does not address when an agency is required to prepare an SEIS. The
Council on Environmental Quality (“CEQ”) regulations provide that agencies:

      Shall prepare supplements to either draft or final environmental impact
      statements if: (I) The agency makes substantial changes in the proposed
      action that are relevant to environmental concerns; or (ii) There are
      significant new circumstances or information relevant to environmental
      concerns and bearing on the proposed action or its impacts.

40 C.F.R. § 1502.9(c)(1). The Corps’ NEPA regulations provide that an SEIS should
be prepared “whenever required” by the CEQ regulation. 33 C.F.R. § 230.13(b).
Here, the Corps agrees that a spring rise will have a significant environmental impact;
that is why it did not prepare a FONSI. Thus, the issue is whether an SEIS was
required for the 2006 Master Manual revision under either the substantial change or
the significant new circumstances standard in 40 C.F.R.§ 1502.9(c)(1). “A change is
substantial if it presents a seriously different picture of the environmental impact” of
the agency’s actions. Arkansas Wildlife, 431 F.3d at 1102 (quotations omitted).

      Missouri argues that an SEIS was required because the Modified Conservation
Plan adopted in the 2004 Master Manual did not include a spring rise and therefore
the 2006 revision adopting a spring rise is a substantial change from the agency’s prior
action. This contention is contrary to established law. A substantial change that
requires an SEIS under 40 C.F.R.§ 1502.9(c)(1)(I) is one that is not “qualitatively
                                           -7-
within the spectrum of alternatives that were discussed” in a prior FEIS. Dubois v.
U.S. Dep’t of Agric., 

, 1292 (1st Cir. 1996), cert. denied, 

 (1997), quoting Forty Most Asked Questions Concerning CEQ’s National
Environmental Policy Act Regulations, 46 Fed. Reg. 18026, #29b (March 23, 1981).
For this reason, an agency’s decision to select a previously rejected alternative is not
a substantial change requiring an SEIS if “the relevant environmental impacts have
already been considered.” Friends of Marolt Park v. U.S. Dep’t of Transp., 

, 1097 (10th Cir. 2004); see Arkansas Wildlife, 431 F.3d at 1102 (SEIS required
only if “the changed plans or circumstances will affect the quality of the human
environment in a significant manner . . . not already considered by the federal
agency”); Marsh, 490 U.S. at 374 (same, applying 40 C.F.R. § 1502.9(c)(1)(ii)).

       This principle is consistent with cases holding that on-going actions such as
operating a system of dams and reservoirs in drought years are not “major Federal
actions” within the meaning of NEPA if the agency is “simply operating the facility
in the manner intended.” Upper Snake River Ch. of Trout Unltd. v. Hodel, 

, 235 (9th Cir. 1990). As the Supreme Court recently observed, “[w]here the
preparation of an EIS would serve ‘no purpose’ in light of NEPA’s regulatory scheme
as a whole, no rule of reason worthy of that title would require an agency to prepare
an EIS.” Dep’t of Transp. v. Public Citizen, 

, 767 (2004).

       Missouri further argues that an SEIS was required because none of the spring
rise alternatives considered in the FEIS were bimodal. Though literally true, the
argument is misleading. The default spring rise plan in the FWS 2003 Amended BiOp
was bimodal, and the ROD adopting the 2004 Master Manual expressly noted the
need for further action to comply with the 2003 Amended BiOp. Thus, we held in
Mo. River that the 2004 Master Manual was consistent with the FWS 2003 Amended
BiOp. 421 F.3d at 627. The issues in Mo. River included a NEPA challenge to the
2004 FEIS, yet no party argued that the FEIS was inadequate because the spring rise
options it analyzed did not include the FWS bimodal default plan. Any argument that

                                          -8-
NEPA compliance required separate analysis of a bimodal plan should have been
made in Mo. River, where we approved an FEIS omitting that analysis.

       More importantly, the Corps has not ignored the issue whether a bimodal spring
rise plan will have significantly different environmental impacts. In an analysis
“tiered”6 to the FEIS, the EA comprehensively compared the impacts of the bimodal
spring rise in the 2006 Master Manual revision with the spring rise options studied in
the FEIS and concluded that the bimodal spring rise plan is within the range of
impacts previously studied and is not a substantial change from the historical range
of release levels on the river. This was the proper inquiry under 40 C.F.R.
§ 1502.9(c)(1)(I). As there is no tenable claim of “significant new circumstances or
information relevant to environmental concerns” within the meaning of 40 C.F.R.
§ 1502.9(c)(1)(ii),7 we agree with the district court that the Corps was not arbitrary or
capricious in deciding not to prepare an SEIS.

      Finally, Missouri argues that the Corps violated NEPA when it failed to follow
the EA with either an EIS or a FONSI. This is an unduly restricted view of the
agency’s options for complying with NEPA’s procedural mandates. The Corps’
regulations provide that an EA is used “for determining whether to prepare an EIS or
a FONSI,” and “[a] FONSI shall be prepared for a proposed action . . . for which an
EIS will not be prepared.” 33 C.F.R. §§ 230.10(a), 230.11. However, these
provisions must be read in conjunction with CEQ’s implementing regulations, see 33
C.F.R. § 230.1, which sensibly provide that “[a]gencies may prepare an environmental

      6
       An EA may be tiered to an earlier EIS “to eliminate repetitive discussions of
the same issues and to focus on the actual issues ripe for decision.” 40 C.F.R.
§ 1502.20. A tiered analysis incorporates discussions from the EIS by reference.
      7
       Missouri asserts that a U.S. Department of Agriculture statement that federal
crop insurance will not cover losses from flooding caused by a spring rise is new
information the impact of which was not analyzed in the EA. Missouri cites no
evidence in the administrative record establishing that USDA has made any such crop
insurance decision. Therefore, we decline to consider this unsupported assertion.
                                          -9-
assessment on any action at any time in order to assist agency planning and
decisionmaking.” 40 C.F.R. § 1501.3(b). Neither the Corps’ nor CEQ’s regulations
prescribe a specific process to determine whether to prepare an SEIS. Here, the Corps
prepared an EA, not to help it decide whether to prepare an EIS, but rather to
determine whether the change in agency action required an SEIS. As this case
illustrates, it is reasonable to expect that the Corps will sometimes determine that a
FONSI is not appropriate because the action being taken has a significant impact on
the environment, but an SEIS is not required because the impact was sufficiently
analyzed in an earlier FEIS. This approach is neither a misuse of the EA procedure
nor a violation of NEPA.

      The judgment of the district court is affirmed.
                     ______________________________




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