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Bureau of Reclamation : an assessment of the environmental impact statement on the operations of the Glen Canyon Dam : report to Congressional committees PDF

220 Pages·1996·11.8 MB·English
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Preview Bureau of Reclamation : an assessment of the environmental impact statement on the operations of the Glen Canyon Dam : report to Congressional committees

United States General Accounting Office GP0 Report to Congre^srtSrtal Committees October 1996 BUREAU OF RECLAMATION An Assessment of the Environmental Impact Statement on the Operations of the Glen Dam Canyon years 1921 -1996 GAO/RCED-97-12 GAO United States General Accounting Office Washington, D.C. 20548 Resources, Community, and Economic Development Division B-272927 October2, 1996 The Honorable FrankMurkowski Chairman The HonorableJ. BennettJohnston Ranking MinorityMember Committee on Energy and Natural Resources United States Senate The Honorable Don Young Chairman The Honorable George Miller Ranking Minority Member Committee on Resources House ofRepresentatives This reportrespondsto subsection 1804(b) ofthe Grand Canyon ProtectionActof 1992 (title XVIII ofP.L. 102-575), whichrequired gao to auditthe Bureau ofReclamation'sfinal environmental impact statement on the operations ofthe Glen Canyon Dam. The report discusses (1) whether Reclamation's determination ofthe impact ofvarious dam-operating alternatives on selected resources was reasonable and (2) what, ifany, concernsstill exist on thepart ofkeyinterestedparties aboutthe final impactstatement. We areproviding acopy ofthis reporttothe Secretary ofthe Interior, theAssistant Secretary forWater and Power, and the Commissioner ofthe Bureau ofReclamation. We will also make copies available to others upon request. Thisreportwasprepared underthe direction ofVictor S. Rezendes, Director, Energy, Resources, and Science Issues, who can be reached at (202) 512-3841 ifyou oryourstaffhave anyquestions. Major contributorsto thisreport are listed in appendix XIII. Keith O. Fultz Assistant Comptroller General Summary Executive Purpose Since the Glen Canyon Dam, located in Page, Arizona, was completedby the Bureau ofReclamation in 1963, ithasbeen used to generate power duringperiods ofhigh demand, commonly known aspeakingpower. The fluctuatingreleases ofwaterassociated with the dam'speakingpower operationshave caused concerns aboutthe detrimental effects such flows have on downstream resources, particularlythose located in the Grand Canyon. In response to these concerns, the Secretary ofthe Interior, in July 1989, directedthe Bureau ofReclamation to prepare an environmentalimpact statementthatwouldreevaluate the Glen Canyon Dam's operations. The purpose ofthe reevaluation wasto determine specific options foroperatingthe dam thatcould minimize the adverse impactsonthe downstream environmental andrecreational resources, as well as on NativeAmericaninterests in the Glen and Grand canyons, while stillproducing hydropower. Figure 1: Location oftheGlen Canyon Dam 7T~ I i f i ¥>:¥:::¥.*::: wWA 1ri Utah :f::t.X ^.Gutm'tof) \ i \ " ^y River \ Nevada IIP Colorado_jf J S Gten i % Canym J /~y•Q&Dam |FSan JuanJ \ if! < |jS j^^ I y_„i \\^s^ N 6f/#WtmelImm&<4m/iI*. -'*<< ^^5>BtjFlakGPonei} Up'pieyCo'tFoHvrearcJtoT^J>j \ K:\v-v:v"-*IMj ^flbs^ f^ver Basin Hoovd^Dam/3 :^r*:: S^i. i • GrandCalyon S Hp ^R,v California \jjSS* ? New Mexico Arize I^L^^^^^^^^eISII £:•:•:•:••• %| Source: Bureauof Reclamation. Page2 GAO/RCED-97-12 Glen Canyon Dam'sEnvironmental ImpactStatement ExecutiveSummary In October 1992, the Congress enacted the Grand Canyon ProtectionAct of 1992 (title XVIII ofP.L. 102-575), which requiredthe Secretary ofthe Interior to complete the environmentalimpactstatementby October30, 1994. The actalso required that gaoauditthe costs and benefits ofthe various operating alternativesidentified in the final environmental impact statement. Inpreparing the statement, Reclamation studied the potential impact ofvarious flow alternatives on selected resources. Reclamation reported the results ofthese studiesin the final environmental impact statement on March 21, 1995. As discussedwith the responsible congressional committees, forthe purpose ofthisaudit, gao examined (1) whether Reclamation'simpactdeterminationswere reasonable and (2) what, ifany, concerns still existaboutthe Glen Canyon Dam's final environmental impact statement. The act also requires that on the basisof the findings, conclusions, and recommendations made in the environmental impact statement and the gao auditreport, the Secretaryis to adopt criteriaand operatingplans forthe dam. Ftork""«?rminH Before the construction ofthe Glen Canyon Dam, the Colorado River's sediment-laden flows fluctuated dramaticallyduring differentseasonsof the year. Annual daily flows ofgreaterthan 80,000 cubic feetpersecond were common duringthe springrunoff. In contrast, flows oflessthan 3,000 cubic feetper second were typical throughoutthe late summer, fall, andwinter. Watertemperatures ranged from nearfreezinginthe winterto more than 80 degrees Fahrenheitinthe summer. The construction ofthe Glen Canyon Dam alteredthe natural dynamics ofthe Colorado River corridorthroughthe Glen and Grand canyons. The dam replaced the dramatic seasonal flowvariationswith significant daily fluctuations, greatlyreduced the amount ofsedimentin the water, andresultedin nearly constantwaterrelease temperatures ofabout46 degrees Fahrenheit. As earlyas 1982, the Secretary ofthe Interiorinitiatedthe Glen Canyon Environmental Studies ofthe effects ofthe dam. These studieswere led by Reclamationand conducted by anumber ofdifferentagencies. In 1989, the Secretary designated Reclamation as the lead agencyin preparing an environmental impact statement. Otheragenciesand individuals participated in these efforts, including federal and state resource agencies, Indian tribes, private consultants, universities, and river guides. Toprotect the downstream resources until the completion ofthe impact statement and the adoption ofanew operatingplan forthe dam, in November 1991 Reclamation implemented interim operating criteria The interim Page3 GAO/RCED-97-12 GlenCanyonDam'sEnvironmental ImpactStatement ExecutiveSummary operating criteriareducedthe maximum peakreleases and daily fluctuations. Withthepassage ofthe Grand Canyon ProtectionAct of 1992, the Congressrequiredthatthe Glen Canyon Dam be operated toprotect andrestore the downstream resources ofthe Grand Canyon National Park andthe Glen Canyon National RecreationalArea The National Environmental PolicyActof 1969 (42 U.S.C. 4321 et seq.) requiresthatadetailed environmentalimpact statementbe prepared for every majorfederalactionthatmay significantly affectthe quality ofthe human environment. The actanditsimplementingregulations setforth the requirements forpreparingan impactstatement. Among otherthings, a statementmust(1) addressthe purpose ofand need forthe action, (2) describe the environmentthatwillbe affected, (3) identify alternatives tothe proposed action, (4) presentthe environmentalimpacts ofthe proposed action (includingthe direct, indirect, and cumulative impacts), and (5) identifythe agency'spreferred alternative. The act does not require, and Reclamation did notperform, acostandbenefit analysis of the proposedaction. Inpreparingthe environmentalimpact statement forthe operation ofthe Glen Canyon Dam, Reclamationidentified 11 resourcesaffected bythe dam's operationsto be analyzed in detail: water, sediment, fish, vegetation, wildlife and habitat, endangered and otherspecial-status species, cultural resources, airquality, recreation, hydropower, and non-use value. (Non-usevalues have been definedasthosevalues thatpeople may receive from the knowledge thatsuch things asrare plantsand unspoiled natural environments exist, evenifpeople do notconsume or use these goods directly.) Inaddition, the impactstatementidentified nine alternative operational scenariosto be studiedin detail. These alternatives canbe divided into three descriptive categories: unrestricted fluctuatingflows (two alternatives, includingthe no-action alternative); restricted fluctuating flows (fouralternatives); and steady flows (three alternatives). In the finalimpactstatement, Reclamationrecommended the Modified Low Fluctuating Flow asthepreferred alternative. This alternative was developed to reduce daily flow fluctuationswell below the dam'sprevious operatinglevelsand toprovide periodic high, steady releases ofshort duration; the goal ofthisalternative wasto protect or enhance downstream resourceswhile allowinglimited flexibilityforpower operations. Page4 GAO/RCED-97-12GlenCanyon Dam'sEnvironmental ImpactStatement Executive Summary m P?p<iiiltQ in RHpf &eneral> Reclamation used appropriate methodologies and the best available information in determining the potentialimpact ofthe dam's various flow alternatives on selected resources, gao identified some shortcomingsand controversyin Reclamation's application ofcertain methodologies, and some ofthe datathat Reclamation used in makingits impact determinations were dated, preliminary, orincomplete. These limitations, combinedwith the inherentuncertaintyassociatedwith making forecasts, reduces the precision ofthe impacts contained inthe statement, and some uncertainty, such asthe impact ofsteady flows on fishresources, remains. Nonetheless, accordingto gao'sanalysis and the opinions ofexperts, these limitations are notsignificant enoughto alter the relative rankingofthe flow alternatives norrenderthe final environmentalimpactstatement unusable asadecision-making document. Furthermore, Reclamation recognizesthatuncertaintiesstill exist. To address these concerns, Reclamationintendstoinitiate aprocess of "adaptive management" that would provide forlong-term monitoring and research to measure the actual effects ofthe selected alternative. The results ofthis effortwould form the basis forpossible future modifications ofthe dam's operations. Many ofthe keyinterestedparties affected bythe Glen Canyon Dam's environmental impact statement supportthe process used by Reclamation to develop the impact statement as well asthe implementation ofthe preferred alternative. However, while expressingtheirsupport, some interestedparties raised specific concernsthatstill existaboutthe final environmental impactstatement, including (1) the mannerin which compliance with the Endangered SpeciesActwillbe achieved, (2) the economic impact ofreducingthe Glen Canyon Dam's hydroelectric power capacity, (3) the consideration ofotherpossible causes ofadverse downstream impacts, (4) the difficulties inmeasuring the impactof changesinthe dam's operations, (5) the adequacy ofthe measures for reducing the frequencyofunscheduled floods, (6) the need forinstalling multilevel waterintake structures (selective withdrawal structures) on the dam to raise the downstream watertemperature, and (7) the implementation ofthe Adaptive Management Program. Page5 GAO/RCED-97-12 GlenCanyonDam'sEnvironmental ImpactStatement ExecutiveSummary Principal Findings Impact Determinations Are Inpreparingthe environmentalimpactstatement, Reclamation used a Usable for variety ofmethodologies and datasourcesto studythe impactofthe Decision-Making various dam flow alternatives on hydropower, non-usevalues and other resourceslocated below the dam. Generally, gao found the methodologies usedto be reasonable and appropriate. Forexample, the power analysis was conducted by acommittee ofspecialists representingthe federal government, the utilityindustry, private contractors, and the environmental community. This committee used utility-specific dataand state-of-the-art simulation models to estimate the economic impactofthe alternative dam flows onlarge regional utilities. In assessing Reclamation's implementation ofthe various methodologies, gao did note several shortcomings and controversy overthe methodology used to estimate non-use values. For example, in the hydropoweranalysis, Reclamation's assumptions do not explicitlyincludethe mitigating effect ofhigherelectricityprices on electricity demand (price elasticity), gao also foundthat Reclamation's assumptionsaboutfuture natural gasprices were relativelyhighand thattwo computational errorswere made during the thirdphase ofthe poweranalysis. These limitations suggestthatthe estimated economic impacts forpowerare subjectto uncertainty. However, Reclamation and many experts associated with the process do notbelieve thatthese limitations make the results ofthe analysisunusable. For example, an associationthatrepresentsthe affectedpowerutilities, whichhas maintained throughoutthe powerstudiesprocessthatthe impactstatement understates the coststo the power system, does not believe that Reclamation's costestimate is understated by alarge magnitude. To quantify the impactofvarious dam flow alternatives on recreationand non-usevalue, Reclamation used amethodology called contingentvaluation. The use ofcontingentvaluation studies, which rely on surveys to elicitinformation from consumersto estimate how much theywould be willing to pay forsomethingis controversial. Although contingentvaluationis currentlythe only known approach forestimating non-usevalues, some prominent economistsquestionwhetherthis methodology can accurately elicitthe value consumers place on non-use goods. However, many economistsand survey researchers working in the natural resource and environmental areas have developed and used this methodology. Although these shortcomings affectthe estimates for the Page6 GAO/RCED-97-12 GlenCanyonDam'sEnvironmental ImpactStatement Executive Summary alternatives, itis unlikelythattheywould altertherelative ranking ofthe fluctuatingand steadyflow alternatives. gao also found that Reclamation generally used the best available datain makingitsimpact determinations. Forexample, forinformation on culturalresources andproperties, Reclamation wentbeyond the federal requirements forthe development ofanimpact statementbyperforming assessments ofall previouslyidentified archeological siteswithinthe Colorado Rivercorridorinthe Glenand Grand canyons. Accordingto many experts, when completed, this effort generated the bestand most currentscientific information available. However, gao also found some limitationsinthe datausedin the development ofthe impactstatement. Specifically, some ofthe informationwas dated, some waspreliminary, and some wasincomplete. For example, to assessthe economic impact of the alternative flows on recreational activities, Reclamation used a 1985 survey ofasample ofanglers, day-rafters, andwhite-waterboaters that askedabouttheirexperiences onthe Colorado Riverandwhat effect, if any, differentstreamflowswould have on theirrecreational experiences. Although Reclamation updated some ofthe datato 1991, it acknowledges thatthe surveyinformationis generally dated. The National Research Council generally foundthe analysis tobe adequate. Many ofthe results ofthe sedimentstudies at Glen Canyon were preliminary, were in draftform, and had notbeenpublished atthe time thatthe draftoreventhe final impactstatementwaswritten. However, accordingto the researchersthat gao interviewed, no new oradditional information on sedimentimpactshasbeen obtainedthatwould alterthe information orconclusionspresented in the final impactstatement. Finally, the information on some resources isincomplete, asisthe knowledge ofhow changes inthe Glen Canyon Dam's operationswill affectthose resources. For example, inpartbecause ofincomplete data, the experts' opinionsvary on the interactions between native and normative fish and how operational changes would affectthese interactions and, ultimately, fish populations. In its final biological opinion, the U. S. Fish and Wildlife Service stated that Reclamation's preferred alternative forthe dam's future operations, the Modified Low FluctuatingFlow alternative, is likely tojeopardize the existence oftwo native endangered fish species (the humpback chub and the razorback sucker). The Service identified actions thatwould modify the preferred alternative with seasonally adjusted steady flows. The Service and Reclamation agreed to categorize these flowsas experimental, orresearch Page7 GAO/RCED-97-12 GlenCanyon Dam'sEnvironmental ImpactStatement Executive Summary flows. The purpose ofthisresearchis to studythe effects ofsteady flows on endangered and native fish. Reclamationrecognizes that many uncertainties aboutthe actualimpactof the various flow alternatives still exist. To address such concerns, Reclamation intendsto initiate aprocess of"adaptive management" that wouldprovide forlong-term monitoring, research, and measurement of the effects ofthe selected alternative. The results ofthis effortwould form the basis forfuture modifications ofthe dam's operations. Most Key Parties Support The process for selectingapreferred alternative forthe future operations the Preferred Alternative, ofthe Glen Canyon Dam considered many factors, such asprotecting but Some Concerns natural and cultural resources and maintaining hydropower generating Remain capability, andinvolved manypartieswith diverse interests. Reclamation's goalwasto selectan alternative dam-operatingplanthatwouldpermit downstream resourcesto recoverto acceptable long-term management levels while maintaining some level ofhydropowerflexibility. Reclamation believesthatitaccomplished this goal by selectingthe Modified Low Fluctuating Flowasthe preferred alternative. Accordingto Reclamation, this flowalternative was developedto reduce daily flow fluctuations well below the dam's historic operations andtoprovideperiodic high, steady waterreleases ofshort duration with the goal ofprotecting orenhancing the downstream resourceswhile allowinglimited flexibility forpower operations. Thisalternative hasthe same annual and essentially the same monthlywaterreleases asthe dam's historic operationsbutwould restrict daily and hourlywaterreleases more thanpreviously. gaojudgmentally selected37 keyinterestedpartiesand surveyedthem on whether they supported Reclamation'spreferred alternative and whether they have any remaining concerns aboutimplementingthis alternative as the future operatingplan forthe Glen Canyon Dam. gao'sjudgmental sample consisted ofall ofthe organizations and individualsthat Reclamationidentified as providing significant comments on the draft impact statement, any organizationsthatwere considered cooperating agencies inthe impactstatement's developmentprocess, and otherkey interested parties. Over 83 percent (25 of30) ofthe respondents to gao's survey supported the preferred alternative, and many expressed support forthe process used by Reclamation to develop the impact statement. Of the five remainingrespondents, three stated thatthey had no position on the issue, while two, the SanJuan Southern Paiute Tribe andthe Grand Canyon River Guides, believed thatthe currentinterim operating criteria Page8 GAO/RCED-97-12 GlenCanyonDam'sEnvironmental ImpactStatement

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