Alternatives for restoring the Colorado River Delta

Natural Resources Journal

Volumn 47, Issue 4, 2007, Pages 917-967

  Wheeler, Kevin G ^a   Pitt, Jennifer ^b   Magee, Timothy M ^a   Luecke, Daniel F ^c  

^a University of Colorado   (United States)

^b ENVIRONMENTAL DEFENSE FUND   (United States)

^c Environmental Water Resources Expert   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

DAM CONSTRUCTION; ECOSYSTEM MANAGEMENT; ENVIRONMENTAL IMPACT; ENVIRONMENTAL MANAGEMENT; ENVIRONMENTAL PROTECTION; ENVIRONMENTAL RESTORATION; FLOOD CONTROL; LAKE WATER; RIPARIAN FOREST; RIVER FLOW; WATER STORAGE; WETLAND;

COLORADO DELTA; LAKE MEAD; MEXICO [NORTH AMERICA]; NORTH AMERICA; UNITED STATES;

EID: 46349085954     PISSN: 00280739     EISSN: None     Source Type: Journal    
DOI: None     Document Type: Article

References (175)

1. Jennifer Pitt. et al., Two Nations, One River: Managing Ecosystem Conservation in the Colorado River Delta, 40 NAT. RESOURCES J. 819, 824 (2000).
2. See PHILIP L. FRADKIN, A RIVER NO MORE330 (Alfred A. Knopf, Inc. 1981).
3. See Edward P. Glenn et al., Effects of Water Management on the Wetlands of the Colorado River Delta, Mexico, 10 CONSERVATION BIOLOGY1175,1177 (1996).
4. Michat Kowaleski et al., Dead Delta's Former Productivity: Two Trillion Shells at the Mouth of the Colorado River, 28 GEOLOGY 1059,1062 (2000).
5. For a complete discussion of ecosystem types, see FRANCISCO ZAMORA-ARROYOET AL., CONSERVATION PRIORITIES IN THE COLORADO RIVER DELTA, MEXICO AND THE UNITED STATES(Sonoran Institute, Environmental Defense, University of Arizona, Pronatura Noroeste Dirección de Conservación Sonora, Centro de Investigaci_on en Alimentación y Desarrollo, and World Wildlife Fund-Gulf of California Program 2005), available at http://sonoran.org/ (follow "Reports" hyperlink; then follow "Conservation Priorities in the Colorado River Delta" hyperlink).
6. Several birds found in the delta are listed as endangered in the United States, including the southwest willow flycatcher and the Yuma clapper rail. See Endangered and Threatened Wildlife and Plants, Lists, Endangered and Threatened Wildlife, 50 C.F.R. § 17.11 (2005). Additionally, Mexico lists Heernan's gull, the elegant tern, reddish egret, peregrine falcon, the brant, and great blue heron as threatened, in need of special protection, or rare. See NORMA Oficial Mexicana NOM-059-ECOL,1994, que determina las especies y subespecies de flora y fauna silvestres terrestres y acuáticas en peligro de extinción, amenazadas, raras y las sujetas a protección especial, y que establece especificaciones para su protección (1994), available at http://www.ine.gob.mx/ueajei/publicaciones /gacetas/227/especies.html (last visited Feb. 4,2008).
7. See 50 C.F.R. § 17.11. Other endangered animals, such as the Colorado delta clam, are so rare that recent surveys identified as few as 12 individuals. See Kowaleski et al., supra note 4, at 1061. Endangered aquatic animals include the vaquita porpoise, the world's smallest and most endangered marine mammal; the totoaba fish; and the desert pupfish. Id.
8. DALE PONTIUS ET AL., COLORADO RIVER BASIN STUDY: FINAL REPORT2 (1997) (report to the Western Water Policy Review Advisory Commission), available at http://wwa.colorad.edu/resources/colorado_river/ pontius%20colorado.pdf.
9. Reclamation's principal planning model, the Colorado River Simulation System (CRSS), was used in this study. The particular version used to develop a baseline was Reclamation's official model as of November 1, 2005, which incorporates modeling assumptions in the Record of Decision for the Interim Surplus Guidelines 2002, Secretarial Implementation Agreement and several recent modifications made by Reclamation. These modifications include expansion of the period of record to 90 years of reconstructed hydrology (1906-19P5), a shortage criteria referred to as 80P1050, which aims to protect Mead's pool elevation of 1050 feet above mean sea level with an 80-percent probability; a Level 2 shortage criteria was also implemented in this version of CRSS (as implemented and described in the 2002 FEIS) and updated initial conditions for reservoir contents.
10. BUREAU OF RECLAMATION, U.S. DEP'T OF INTERIOR, COLORADO RIVER INTERIM SURPLUS CRITERIA, FINAL ENVIRONMENTAL IMPACT STATEMENT, vol. I, ch. 3, at 3-16-13 (2000), available at http://www.usbr.gov/lc/region/ g4000/surplus/SURPLUS_FEIS.HTML (last visited Nov. 18, 2007) [hereinafter SURPLUS CRITERIA]; BUREAU OF RECLAMATION, U.S. DEP'T OF INTERIOR, FINAL ENVIRONMENTAL IMPACT STATEMENT, IMPLEMENTATION AGREEMENT, INADVERTENT OVERRUN AND PAYBACK POLICY, AND RELATED FEDERAL ACTIONS, Vol. I. ch. 3, at 3.12-13 to 3.12-17 (2002), available at http://www.usbr.gov/lc/region/g4OOO/FEIS/Volume%201.pdf [hereinafter IMPLEMENTATION AGREEMENT].
11. Niklas S. Christensen et al., The Effects of Climate Change on the Hydrology and Water Resources of the Colorado River Basin, 62 CLIMATIC CHANGE337 (2004). The topic of what the impacts of climate change will be in the region is currently being debated and the authors chose not to delve into this topic during this study to remain consistent with Reclamation's current assumptions. We recognize, however, that studies have indicated that climate change is expected to reduce precipitation in the Colorado River Basin by 14 to 18 percent over the next century.
12. PONTIUS ET AL., supra note 8, at 14.
13. Edward P. Glenn et al., Status of Wetlands Supported by Agricultural Drainage Water in the Colorado River Delta, Mexico, 34 HORTSCENCE 39 (1999);
14. DANIEL F. LUECKE ET AL., A DELTA ONCEMORE: RESTORING RIPARIAN AND WETLAND HABITAT IN THE COLORADO RIVER DELTA,iv, 12 (Envtl. Defense Fund 1999), available at http://www.environmentaldefense.org/ documents/425_delta.pdf;
15. Francisco Zamora-Arroyo et al., Regeneration of Native Trees in Response to Food Releases from the United States into the Delta of the Colorado River, 49 J. ARID ENV'TS49, 62 (2001). The baseflow is needed to maintain backwaters and a wetted soil perimeter in the main stem channel, conditions necessary to sustain the habitat for migratory and resident birds that depend on insects for food. Flood flows are important to restore and maintain riparian vegetation in arid-zone rivers. Id.
16. These inefficiencies in Colorado River management include cancelled water orders, river and reservoir maintenance, and seepage from dams.
17. IMPLEMENTATION AGREEMENT, supra note 10, vol. I, ch. 3, at 3.12-3.
18. See Pitt et al., supra note 1, at 821.
19. ASOCIACIÓN ECOLÓGICA DE USARIOS DEL RÍO HARDY-COLORADO, A.C. ET AL., BINATIONAL DECLARATION: THE COLORADO RIVER (2001), http://www.biologicaldiversity.org/swcbd/Programs/ watersheds/lcr/binational.pdf. See Pitt et al., supra note 1. In 2001, 20 non-governmental organizations signed the Binational Declaration for the Colorado River, including Asociación Ecológica de Usarios del Río Hardy-Colorado, A.C.; Center for Biological Diversity; Centro de Derecho Ambiental y Integración Económica de Sur, A.C.; Centro Intercultural de Estudios de Desiertos y Océanos, A.C.; Centro Regional de Estudios Ambientales y Cientificos; Defenders of Wildlife; ECO-SOL Educación y Cultura Ecológica A.C.; Environmental Defense; El Grupo Ecológista Antares, A.C.; Friends of Arizona Rivers; High Country Citizens' Alliance; International Rivers Network; La Sociedad de Historia Natural Niparajá, A.C.; Living Rivers; Pacific Institute for Studies in Development, Environment, and Security; Pro Esteros, Pronatura Peninsula de Baja California; Sierra Club, Colorado River Task Force; Sonoran Institute; and Southwest Rivers. Id.
20. Pitt et al., supra note 1, at 849-52.
21. We did not model transfers of undeveloped water rights. From a hydrologic perspective, such a transfer would be similar to diverting system water to the Delta. For discussion of market transfers to the Colorado Delta, see id. at 856-59.
22. Recent changes to the Law of the River include new federal laws such as the Grand Canyon Protection Act of 1992 and the Interim Surplus Guidelines. Grand Canyon Protection Act of 1992, Pub. L. No. 102-575, 106 Stat. 4669 (1992); BUREAU OF RECLAMATION, U.S. DEP'T OF INTERIOR, COLORADO RIVER INTERIM SURPLUS GUIDELINES: FINAL ENVIRONMENTAL IMPACT STATEMENT(2001) [hereinafter SURPLUS GUIDELINES]. As of this writing, the Bureau of Reclamation has completed a final environmental impact statement for shortages guidelines.
23. BUREAU OF RECLAMATION, U.S. DEP'T OF INTERIOR, COLORADO RIVER INTERIM GUIDELINES FOR LOWER BASIN SHORTAGES AND COORDINATED OPERATIONS FOR LAKES POWELL AND MEAD: FINAL ENVIRONMENTAL IMPACT STATEMENT(2007), available at http://www.usbr.gov/lc/region/programs/strategies/ FEIS/index.html.
24. See Defenders of Wildlife v. Norton, 257 F. Supp. 2d 53 (D.C. Cir. 2003);
25. Press Release, Defenders of Wildlife, Groups Sue U.S. to Protect Mexican Wetlands and U.S. Endangered Species (June 28, 2000), available at http://www.defenders.org/newsroom/press_releases_folder/2000 (scroll down to June press releases);
26. see also ASOCIACIÓN ECOLOGICA DE USARIOS DEL RÍO HARDY-COLORADO, A.C. ET AL., supra note 17. Although the court has ruled that the United States is not obligated to manage the Colorado River for endangered species that rely on the river in Mexico, many environmental groups contend that the United States must share with Mexico in the obligation to protect and restore the habitats of the Colorado Delta. Id.
27. Letter from Sylvia A. Waggoner, Division Engineer, International Boundary and Water Commission U.S. and Mexico, to Jayne Harkins, Manager, Lower Colorado River Office, U.S. Bureau of Reclamation (Sept. 8, 2000), reprinted in SURPLUS CRITERIA, supra note 10, vol. III, at B-278-B-280 (stating that "the United States government does not assume any obligation to mitigate for adverse impacts in Mexico").
28. Minutes of the U.S. and Mexican Sections of the International Boundary and Water Commission, Conceptual Framework for U.S.-Mexico Studies for Future Recommendations Concerning the Riparian and Estuarine Ecology of the Limitrophe Section of the Colorado Riverand its Associated Delta, Minute 306 (Dec.13,2000), available at http://www.ibwc.state.gov/ Files/Minutes/Min306.pdf [hereinafter Minute 306].
29. See Pitt et al., supra note 1, at 840-41.
30. The list of researchers is extensive, with some of the notable efforts mentioned here. Institutions that have demonstrated a commitment include, in the United States, the University of Arizona (at both the Environmental Research Laboratory and the National Science Foundation funded Research Coordination Network for the Colorado River Delta) and, in Mexico, the Centro de Investigación Cientifica y de Educación Superior de Ensenada and the Centro de Investigación en Alimentación y Desarrollo.
31. For interested government agencies, see generally International Boundary and Water Commission, United States-Mexico Colorado River Delta Symposium Proceedings 67-74 (Sept, 11-12, 2001), available at http://www.ibwc.state.gov/FAO/CRDS0901/English Symposium.pdf.
32. The baseflow is needed to maintain backwaters and a wetted &oil perimeter in the main stem channel, conditions necessary to sustain the habitat for migratory and resident birds that depend on insects for food. Flood flows are important in restoring and maintaining riparian vegetation in arid-zone rivers. Glenn et al., Supra note 13, at 40;
33. LUECKE ET AL., supra note 13, at iv;
34. Zamora et al., supra note 13.
35. IMPLEMENTATION AGREEMENT, supra note 10, vol. I, ch. 2, at 2.2-1. The alternative is described in detail in the section "Description of the Proposed Action and Alternatives," id. at 2-1.
36. PONTIUS ET AL., supra note 8, at 6.
37. SURPLUS CRITERIA, supra note 10, vol. I, ch. 3, at 3.3-6.
38. Paleo-ecological research suggests that over the long term the Colorado's annual average flow may be as low as 14.3 maf. Connie A. Woodhouse et al., Updated Streamflow Reconstructions for the Upper Colorado River Basin, 42 WATER RESOURCES RES., No. W05415, 2006, at 12.
39. See INT'L BOUNDARY & WATER COMM'N WESTERN WATER BULLETIN 1960: FLOW OF THE COLORADO RIVER AND OTHER WESTERN BOUNDARY STREAMS AND RELATED DATA 29 (1960);
40. INT'L BOUNDARY & WATER COMM'M, WESTERN WATER BULLETIN 2003: FLOW OF THE COLORADO RIVER AND OTHER WESTERN BOUNDARY STREAMS AND RELATED DATA 32 (2003);
41. U.S. Geological Survey, Geological Survey Water Supply Paper 1313, Compilation of Records of Surface Waters of the United States through September 1950, pt. 9: Colorado River Basin, 709-29 (1954).
42. LUECKE ET AL., supra note 13, at 1.
43. See generally FRADKIN, supra note 2.
44. LUECKE ET AL., supra note 13, at 13;
45. MICHAEL J. COHEN & CHRISTINE HENGES-JECK, MISSING WATER: THE USES AND FLOWS OF WATER IN THE COLORADO RIVER DELTA REGION16-18 (Pacific Inst. 2001).
46. IMPLEMENTATION AGREEMENT, supra note 10, vol. I, ch. 3, at 3.12-3.
47. We detected this trend in our analysis, which updates the trend documented using the hydrologic record through 1990 in IMPLEMENTATION AGREEMENT, supra note 10, vol. 1, at 3.12-18.
48. See generally ZAMORA-ARROYO ET AL., supra note 5; "Special Issue: The Lower Colorado River Basin and Delta," 49 J. ARID ENV'TS1 (2001) (which contains ten original research papers, two literature reviews, and two policy papers).
49. Zamorra-Arroyo et al., supra note 13, at 50.
50. Daniel W. Anderson et al., Migratory Bird Conservation in the Colorado River Delta Region, in MANAGING FOR HEALTHY ECOSYSTEMS (David J. Rapport et al. eds., 2003).
51. Garcia-Hernandez et al., Willow Flycatcher (Empidonax traillii) Surveys in the Colorado River Delta: Implications for Management, 49 J. ARID ENV'Ts161-70 (2001).
52. Zamora-Azroyo et al., supra note 13.
53. Id.;
54. Julie C. Stromberg, Restoration of Riparian Vegetation in the South-western United States: Importance of Flow Regimes and Fluvial Dynamism, 49 J. ARID ENV'TS17, 18 (2001).
55. See LUECKE ET AL., supra note 13, at 24 (citing the calculations found in D.W. Anderson & Robert D. Ohmart, Vegetation, in INVENTORY AND MONITORING OF WILDLIFE HABITAT 639 (Allen Y. Cooperrider et al. eds., 1986)).
56. Jack M. Payne et al., Ducks Unlimited, Inc., Feasibility Study for the Possible Enhancement of the Colorado Delta Wetlands, Baja California Norte, Mexico 8 (1992);
57. Erik Mellink et al., Non-Breeding Waterbirds of the Delta of the Río Colorado, Mexico, 68 J. FIELD ORNITHOLOGY113, 114 (1997).
58. Osvel Hinojosa-Huerta et al., Distribution and Abundance of the Yuma Clapper Rail (Rallus longostris yumanensis) in the Colorado River Delta, Mexico, 49 J. ARID ENV'TS171 (2001).
59. S. Zengel & E.P. Glenn, Presence of the Endangered Desert Pupfish, (Cyprinodon macularius, Cyprinidontidae) in Cienega de Santa Clara, Mexico, Following an Extensive Marsh Dry Down, 41 Sw. NATURALIST 73 (1996).
60. Jennifer Pitt et al., New Water for the Colorado River: Economic and Environmental Considerations for Replacing the Bypass Flow, 6 DENV. WATER L. REV.70 (2002).
61. Carlos Valdes-Casillas et al., Information Database and Local Outreach Program for the Restoration of the River Hardy Wetlands, Lower Colorado River Delta, Baja California and Sonora, Mexico 18 (1998).
62. See Glenn et al., supra note 3.
63. Kowaleski et al., supra note 4.
64. Vaquita (Phocoena sinus), in MARINE MAMMAL COMMISION: ANNUAL REPORT TO CONGRESS1996 (1997) [hereinafter MARINE MAMMAL COMMMISION].
65. C.A. Flanagan & J.R. Hendrickson, Observations on the Commercial Fishery and Reproductive Biology of the Totoaba, Cyncoscion Macdonaldi, in the Northern Gulf of California 74 FISHERY BULL . 531 (1976) (cited in U.S. BUREAU OF RECLAMATION, DESCRIPTION AND ASSESSMENT OF OPERATIONS, MAINTENANCE, AND SENSITIVE SPECIES OF THE LOWER COLORADO RIVER, BIOLOGICAL ASESSMENT PREPARED FOR U.S. FISH AND WILDLIFE SERVICE AND LOWER COLORADO RIVER MULTI-SPECIES CONSERVATION PROGRAM, vol. IV, at E3.)
66. LUECKE ET AL., supra note 13, at 1.
67. Manuel S. Calindo-Bect et al., Penaid Shrimp Landings in the Upper Gulf of California in Relation to Colorado River Freshwater Discharge, 98 FISHERY BULL. 222, 222 (2000).
68. MARINE MAMMAL CoMMiSSION, supra note 52.
69. Telephone Interview with Karl Flessa, Principal Investigator, Colorado River Delta Research Coordination Network (Dec. 6, 2005).
70. Minute 306, supra note 23.
71. Utilization of the Waters of the Colorado and Tijuana Rivers and of the Rio Grande, Feb. 3, 1944, U.S.-MEX., 59 Stat. 1219, 1265.
72. Criteria for Coordinated Long-Range Operation of Colorado River Reservoirs Pursuant to the Colorado River Basin Project Act of September 30, 1968, Pub. L. No. 90-537, § 602, 82 Stat. 900 (1968) (codified at 43 U.S.C. § 1552 (1968)), available at http:/ /www.usbr.gov/lc/region/g1000/pdfiles/opcriter.pdf.
73. The numerous compacts, court decisions and decrees; contracts; and regulatory guidelines are collectively known as the Law of the River. This collection of documents governs the apportionment and regulates the use and management of the Colorado River. A collection of the most significant documents comprising the Law of the River is available at http://www.usbr.gov/lc/region/pao/lawofrvr.html.
74. The term "operating criteria," as used in this article, refers to the Criteria for Coordinated Long-Range Operation of the Colorado River Reservoirs Pursuant to the Colorado River Basin Project Act of September 30, 1968 (commonly referred to as the Long-Range Operating Criteria or LROC) and to other criteria used to operate each reservoir within the legislated purposes of each project. The authors will be explicit when referring to the LROC.
75. See sources cited in supra note 20.
76. See generally MILTON N. NATHANSON, UPDATING THE HOOVER DAM DOCUMENTS(1978).
77. Over-allocation of the Colorado River is widely recognized. Sixteen and one-half million acre-feet of water are allocated in the Colorado River Compact and the U.S.-Mexico Treaty, yet this exceeds the average annual inflow into the system of 15.1 million acre-feet (maf) from 1906 through 2003, based on Reclamation's natural or virgin-flow estimates. Bureau of Reclamation, U.S. Dep't of Interior, Reclamation: Managing Water in the West, Response of the System to Various Hydrological and Operational Assumptions, Reclamation Modeling Results (presented at Natural Resources Law Center Conference, Boulder, Col., June 2005), http:// wwa-colorado.edu/in_focus/colorado_river /hard_times_conference/Fulp_NRLCpresentation.pdf. Furthermore, a recent paleo-reconstruction of streamflows shows that for the Colorado River the long-term annual mean flow may only be 14.3 million acre-feet.
78. See Woodhouse et al,, supra note 31;
79. see also David H. Getches & Charles C. Meyers, The River of Controversy: Persistent Issues, in NEW COURSES FOR THE COLORADO RIVER: MAJOR ISSUES FOR THE NEXT CENTURY55-56 (Gary D. Weatherford & F. Lee Brown eds., 1986);
80. David G. Tarboton, Hydrologic Scenarios for Severe Sustained Drought in the Southwestern United States, 31 WATER RESOURCES BULL. 803 (1995).
81. The full text of the Colorado River Compact can be found in NATHANSON , supra note 64, vol. I at 4-7. The Compact is also available at http://www.usbr.gov/lc/region/glOOO/pdfiles /ucbsnact.pdf.
82. Utilization of the Waters of the Colorado and Tijuana Rivers and of the Rio Grande, Feb. 3,1944, U.S.-Mex., 59 Stat. 1219, 1265. The Treaty is available at http://www.ibwc.state.gov/Files/1944Treaty.pdf.
83. 373 U.S. 576 (1963) (guaranteeing in-stream flows for some national parks, monuments, and refuges).
84. Arizona v. California, 376 U.S. 340 (1963).
85. However, several recent changes in the Law of the River do require operational changes for the benefit of the environment. The Grand Canyon Protection Act of 1992 authorized flood releases from Lake Powell to flush sediments through the Grand Canyon, and the Recovery Implementation Program for Endangered Fish Species in the Upper Colorado River Basin was developed to protect and improve instream flows, restore habitat, and reduce the adverse effects of non-native fish species.
86. See Pitt et al., supra note 1, at 833-36.
87. IMPLEMENTATION AGREEMENT, supra note 10, vol. I, ch. 3, at 3.12-1.
88. Id.
89. U.S. ARMY CORPS OF ENG'RS, WATER CONTROL MANUAL FOR FLOOD CONTROL: HOOVER DAM AND LAKE MEAD, COLORADO RIVER(1982).
90. See LUCKE ET AL., supra note 13, at 13;
91. Cohen & Henges-Jeck, supra note 35.
92. IMPLEMENTATION AGREEMENT, supra note 10, vol. I, app. G, at B-1, Technical Memorandum No. 1, Analysis of River Operations and Water Supply.
93. Criteria for Coordinated Long-Range Operation of Colorado River Reservoirs Pursuant to the Colorado River Basin Project Act of September 30, 1968, Pub. L. No. 90-537, § 602, 82 Stat. 900 (1968) (codified at 43 U.S.C. § 1552 (1968)).
94. In order to allow for Upper Basin development while ensuring that water would be available for development in the Lower Basin, the 1922 Compact required that the Upper Basin would not deplete the flow at Lee Ferry to less than 75 million acre-feet for any period of ten consecutive years. It further anticipated the need to apportion water to Mexico and declared that the burden to supply that water would be borne equally by the two basins. Consequently LROC specifies a minimum objective release from Lake Powell of 8.23 million acre-feet annually. Supra note 76, § II(2).
95. 43 U.S.C. § 1552(a)(3)(ii).
96. Criteria for Coordinated Long-Range Operation of Colorado River Reservoirs Pursuant to the Colorado River Basin Project Act of September 30,1968, Pub. L. No. 90-537, § 602, 82 Stat. 900 (1968) (codified at 43 U.S.C. § 1552 (1968)), as amended by 69 Fed. Reg. 28,945 (May 19, 2004).
97. See supra note 76. Changes to equalization rules by the Colorado River basin states are not expected to change this trend. Letter to Gale Norton, Secretary, Department of the Interior, from the States of Arizona, California, Colorado, Nevada, New Mexico, Utah, and Wyoming 2 (Feb. 3, 2006), available at http://www.usbr.gov/lc/region/ programs/strategies/consultation/Feb06BasinStatesTransmittalLetter.pdf.
98. Supra note 76, § III(3).
99. Arizona v. California, 373 U.S. 546 (1963): II(B)2.
100. The U.S.-Mexico Water Treaty allocates 200,000 acre-feet of water to Mexico "in any year in which, as determined by the United States Section, there exists a surplus of waters of the Colorado River in excess of the amount necessary to supply uses in the United States." The Interim Surplus Guidelines do not define surplus for Mexico. Consequently, Mexico receives surplus deliveries only when flood control releases are anticipated. Utilization of the Waters of the Colorado and Tijuana Rivers and of the Rio Grande, Feb. 3,1944, U.S.-Mex., art. 10(b), 59 Stat. 1219, 1265. SURPLUS CRITERIA, supra note 10, vol. III, pt. B, Letter 58, at B-278-80.
101. The Interim Surplus Guidelines went into effect on January 1, 2002, although they were suspended until October 16, 2003, when the Secretary of the Department of the Interior signed the Colorado River Water Delivery Agreement, recognizing the completion of the California parties' Quantification Settlement Agreement. SURPLUS GUIDLINES, supra note 20;
102. see Dean E. Murphy, Pact in West Will Send Farms'Water to Cities, N.Y. TIMES, Oct. 17,2003, at A1.
103. Reclamation is considering extension of the Surplus Guidelines in its determination of shortage criteria. See supra note 20.
104. See SURPLUS GUIDELINES, supra note 20, fig. 3.16.1.
105. Letter from Jennifer Pitt, Senior Resource Analyst, Environmental Defense, et al., to Bruce Ellis, Environmental Program Manager, Phoenix Area Office of the Bureau of Reclamation (Mar. 26, 2002) (commenting on the Draft Environmental Impact Statement on the Implementation Agreement, Inadvertent Overrun and Payback Policy, and Related Federal Actions, published in the Final Environmental Impact Statement). See IMPLEMENTATION ACREEMENT, supra note 10, vol. I, ch. 11, at 11-213.
106. See IMPLEMENTATION AGREEMENT, supra note 10, vol. L ch. 3, at 3.1-31.
107. Report from the Secretary of the Interior, to select members of the U.S. Senate Energy, Resource & Appropriations Committees, Modifications to Projects of Title I of the Colorado River Basin Salinity Control Act 11-12 (Feb. 11, 2003) (draft on file with author and the Natural Resources Journal).
108. 43 U.S.C. § 1571(c) (2000).
109. Id. § 1572(a) (2000).
110. Bureau of Reclamation, Notice to interested parties, September 22, 2005: Public Process - Methods to recover or replace the bypass flow, including the Yuma Desalting Plant, available at http:// www.usbr.gov/lc/region/programs/bypass/letter.pdf.
111. Pitt et al., supra note 48, at 68-86.
112. Colorado River Reservoir Operations: Development of Lower Basin Shortage Guidelines and Coordinated Management Strategies for Lake Powell and Lake Mead Under Low Reservoir Conditions, 70 Fed. Reg. 57,322 (Sept. 30, 2005).
113. See generally BUREAU OF RECLAMATION, US. DEP'T OF INTERIOR, LOWER COLORADO RIVER DROP 2 STORAGE RESERVOIR PROJECT: FINAL ENVIRONMENTAL ASSESSMENT(2007), available at http:// www.usbr.gov/lc/yuma/envirorumental_docs/Drop_2/finalea/fea1.pdf. Reclamation defines non-storable flows as "any water exceeding user demand that arrives at Imperial Dam and cannot be sent to another user, sent to storage, or delivered as part of scheduled deliveries to Mexico [and] is inadvertently delivered to Mexico in excess of Treaty obligations." Id. at ES-2.
114. See Defenders of Wildlife et al., Conservation Before Shortage II: Proposal for Colorado 2 River Operations (July 7, 2006), available at http://www.usbr.gov/lc/region/programs/strategies/alternatives/ CBS2.pdf.
115. See BUREAU OF RECLAMATION, U.S. DEP'T OF INTERIOR, COLORADO RIVER INTERIM GUIDELINES FOR LOWER BASIN SHORTAGES AND COORDINATING OFERATIONS FOR LAKE POWELL AND LAKE MEAD, DRAFT ENVIRONMENTAL IMFACT STATEMENTapp. K (2007), available at http://www.usbr.gov/lc/ region/programs/strategies/draftEIS/index.html.
116. BUREAU OF RECLAMATION, ANNUAL REPORT AND OPERATING PLAN FOR THE COLORADO RIVER SYSTEM RESERVOIRS(annually 1971 et seq.).
117. T. Fulp et al., Decision Support for Watershed and River System Management Applications on the Colorado River, in HYDRO'S FUTURE: TECHNOLOGY, MARKETS, AND POLICY: PROCEEDINGS OF THE WATERPOWER'99 CONFERENCE(Peggy A. Brookshier ed., Am Soc. of Civil Engrs. 1999);
118. Edith A. Zagona et al., RiverWare: A Generalized Tool for Complex Reservoir System Modeling, 37 J. AM. WATER RESOURES ASS'N 913-29 (2001).
119. See, e.g., SURPLUS CRITERIA, supra note 10;
120. IMPLEMENTATION AGREEMENT, supra note 10.
121. One of the model's limitations is that the monthly time step obscures many of the effects that occur on a smaller time scale, such as power generation, minimum flows, peak flows, flow duration, etc.
122. Initial reservoir elevations for December 2005 are taken from projections made in the 24-month study published in August 2005. BUREAU OF RECLAMATION, LOWER COLORADO REGION, MOST PROBABLE WATER SUPPLY (2005) (on file with author and the Natural Resources Journal).
123. See, e.g., Zagona et al., supra note 99.
124. The hydrologic traces are produced using an Index Sequential Method, which currently incorporates 90 years (1906 to 1995) of historical hydrologic data about the River. Each trace is a sample from the historical record, using a different year as the starting point. When a sequence reaches the end of the historical record, it is continued by returning to the start of the record. Another limitation of the model is that the historical hydrology used does not include the most extreme known events for the River. In particular, the fossil records of the Delta indicate severe sustained droughts far in excess of droughts in the last 90 years.
125. Reclarmations most recently published study is the FINAL ENVIRONMENTAL IMPACT STATEMENT, IMPLEMENTATION AGREEMENT, INADVERTENT OVERRUN AND PAYBACK POLICY,AND RELATED FEDERAL ACTIONS. IMPLEMENTATION AGREEMENT, supra note 10, vol. 1, ch. 3, at 3.12-3 to 3.12-17.
126. For example, we expect shortage guidelines to be developed by the end of 2007.
127. Quantification Settlement Agreement by and among Imperial Irrigation District, a California irrigation district; the Metropolitan Water District of Southern california, a California metropolitan water district; and the Coachella Valley Water District, a California county water district, Oct. 10, 2003, available at http:// www.crss.water.ca.gov/docs/crqsa/Parts/QSA_SC.pdf.
128. Colorado River Water Delivery Agreement: Federal Quantification Settlement Agreement,Oct.16, 2003, available at http:// www.usbr.gov/lc/region/g4OOO/cxwda/crwda.pdf.
129. See IMPLEMENTATION AGREEMENT, supra note 10, vol. I, app. G, at 2-6. The amount of water transferred increases until the year 2026 when it reaches 388,200 acre-feet per year. Id.
130. Colorado River Water Delivery Agreement - Implementation Agreement, Inadvertent Overrun and Payback Policy, and Related Federal Actions, Colorado River, Arizona, California and Nevada, 69 Fed. Reg. 1Z202 (Mar. 15, 2004).
131. The projected average overrun may in fact underestimate actual overruns and impacts to flows in the delta. Reclamation also states that a maximum overrun in any one year would be as high as 331 kaf. See IMPLEMENTATION AGREEMENT, supra note 10, vol. 1 ch. 3, at 3.12-13. In addition, Reclamation granted a late-year supplemental surplus of 200 kaf to California in 2002 because agricultural water users would run out of their allocated water before the end of the year. See Letter from Gale Norton, Secretary of the Interior, to Gray Davis, Governor of Califonia (Nov.22,2002), available at http:// www.usbr.gov/lc/region/g4000/2002suppaop.pdf.
132. For previous Reclamation modeling of IOP, see INPLEMENTATION AGREEMENT, supra note 10, vol. I, app. C, at 31. This has been removed from the current version of Reclarmation's model.
133. See SURPLUS CRITERIA, supra note 10, vol. L ch. 3, at 3.12-3.
134. Id. vol. II, attachment J, at J-13 to J-14.
135. This modified shortage assumption, titled 80PI050, is described in IMPLEMENTATION AGREEMENT, supra note 10, vol. I, app, G, at 2-7. Reclamation intends to use this assumption as the baseline for the forthcoming Shortage Criteria. Interview with Terry Fulp, Area Manager, Hoover Dam, U.S. Bureau of Reclamation, in Boulder, CO (Mar.6, 2006).
136. IMPLEMENTATION AGREEMENT, supra note 10, vol. 1, ch. 3, at 3.12-13 to 3.12-17
137. SURPLUS CRIFERIA, supra note 10, vol. 1, ch. 3, at 3.3-12.
138. IMPLEMENTATION AGREEMENT, supra note 10, vol. 1, app. G, at 2-5. While this is consistent with the Law of the River, shortage criteria have not yet been adopted for the Lower Basin.
139. PITT ET AL., supra note 1, at 842-49.
140. The Action Alternative scenario of the SIA EIS assumes compliance with all aspects of the Law of the River, including the Basin States Interim Surplus Guidelines as selected by the Record of Decision, the benchmarks set forth for California in the ROD, and federal approval for the Quantification Settlement Agreement (QSA), and incorporation of an Inadvertent Overrun Policy for analyzing the effects downstream of Lake Mead.
141. 3/sec (3,014 acre-feet). Simulated spring flood events are triggered from May through the beginning of June and are required only if a sufficient flood control release has not occurred during the prior 40 months. We selected this interval to assure that a simulated spring flood would be released only if the Delta had not benefited from a sufficient flood control release since the month of January, three years prior, guaranteeing the occurrence of exactly one sufficient flood flow every four calendar years. Floods occur more frequently only when Reclamation implements multiple flood control releases.
142. Off-stream banking in the Lower Basin is allowed under current guidelines, and banking in Lake Mead has recently been proposed by the Colorado River basin states. See supra note 80. This alternative assumes banking will be allowed and that banked water would be treated
143. Water is purchased or leased at the beginning of each calendar year and stored in (or not released from) Lake Mead. Any unused portion of the purchase is carried into subsequent years (banked) for utilization in the next required flood event. We require a sufficient volume of water in the "bank" to allow a simulated spring flood event before any water is released.
144. Water reaches the Delta due to flood control events of at least 263,014 acre-feet over any two consecutive months. In this event, after baseflows were released, the volume of banked water would be set at zero for the remainder of the calendar year.
145. A flood control release is made that results in a volume of water reaching the Delta that is insufficient less than 263,014 acre-feet over two months) to be considered an adequate flood event, and there is sufficient banked water to supplement the flood control event so that it could result in delivery to the Delta of 263,014 acre-feet over two months. In this event, banked water would be released from Lake Mead. This would allow floodplain inundation to occur occasionally at intervals shorter than four years by maximizing the water released from existing flood control regulation without directly impacting any other user of the system.
146. This alternative also requires Mexico to supplement any U.S. flood control releases that are predicted to occur in a quantity too small to meet the Delta's minimum ecological needs (in other words, a flood control spill of less than 263,014 acre-feet over two months) with up to 200,000 acre-feet of surplus water that typically is allocated as surplus flows to Mexico.
147. The baseflows are reduced on the same schedule as CAP. In addition, the frequency of flood flows released for the Delta is increased in the same proportion as the reductions imposed on CAP. For example, if, due to shortage conditions, CAP receives only half of the water originally requested, the baseflow to the Delta would be reduced to 25,000 acre-feet per year and flood flows would be released every eight years.
148. Getting Started with the Graphical Policy Analysis Tool, CADSWES, University of Colorado (2002), http://cadswes.colorado.edu/users/ RiverWare/Releases/GettingStarted WithGPAT.pdf.
149. The reader should take note of the extents of the axes in each graph. Often the axes do not include the zero value to demonstrate the differences between policies, which would be hard to detect otherwise.
150. See, e.g., Analysis of River Operations and Water Supply Technical Memorandum No. 1, in IMPLEMENTATION AGREEMENT, supra note 10, vol. 1, app. G, at 3-6, 3-16.
151. Maximum storage at Lake Mead is 27.3 million acre-feet; maximum storage at Lake Powell is 24.3 million acre-feet. See Bureau of Reclamation, U.S. Dep't of Interior, Boulder Canyon Project - Hoover Dam, Arizona and Nevada, www.usbr.gov/dataweb/html/bcphoover.html, and Bureau of Reclamation, U.S. Dep't of Interior, Upper Colorado Region, Water Resources Group, Upper Colorado River Drainage Basin, www.usbr.gov/ uc/water/basin/tc_cr.html.
152. For a discussion of rules that determine releases from Lake Powell, see SURPLUS CRITERIA, supra note 10, vol. II, attachment J, at J 4-10.
153. See supra note 65.
154. The Banking alternative is similar to the baseline. The alternatives in decreasing order of Lake Mead's storage are baseline, Banking, Mexico Baseflow, Shortage, Mexico Partial Baseflow, and System Release alternatives.
155. This predicted recovery, as illustrated in Figure 5, has begun to occur since the initial conditions for the model were selected for January 2006. As of June 25, 2007, Lake Powell has recovered to 12.9 million acre-feet. Data for historical reservoir conditions can be found at Bureau of Reclamation, U.S. Dep't of Interior, Upper Colorado Region Reservoir Operations, http://www.usbr.gov/uc/crsp/GetSitelnfo.
156. SURPLUS CRITERIA, supra note 10, vol. 1, ch. 3, at 3.2-1.
157. The timing of this maximal difference is an example of occasional simulation results that are difficult to predict due to the interaction of rules and the probabilistic nature of the analysis. However, if the results were easy to predict, simulation would be unnecessary. One possible explanation in this case is that the accumulation of delta flows increases the differences with time while the increasing diversion of water in the Upper Basin tends to mask the differences over time. In addition, the end of the Interim Surplus Criteria in 2016 could be masking the differences.
158. The decadal averages are necessary to show the overall trend of increased surpluses and decreased shortages with the Banking alternative. Select years can be misleading because of the multi-stage surplus and shortage assumptions that Reclamation uses. For example, a level 2 shortage declared in one year decreases the probability that any shortage will be called in the following year.
159. IMPLENMENTATION AGREEMENT, supra note 10, vol. 1, app. G.
160. U.S. ARMY CORPS OF ENG'RS, supra note 73.
161. IMPLEMENTATION AGREEMENT, supra note 10, vol. 1, app. G.
162. The Mexico Baseflow, Mexico Partial Baseflow, and Shortage alternatives have been removed from the graph to improve readability because they overlap the other alternatives. The Mexico Partial Baseflow and Shortage Alternatives fall between the Mexico Baseflow and the System Release alternatives.
163. 43 U.S.C. § 1521(b) (2007).
164. Once again, several alternatives have been omitted for clarity. The Mexico Baseflow, Mexico Partial Baseflow, and Shortage alternatives are between the Banking and the System Release alternatives.
165. We have adjusted the scale of this graph to make the relatively small differences visible.
166. This table documents decadal averages that represent the general trend of decreased impact of the system release alternative on surplus water and increased importance of shortages. Due to the periodicity of delivering the 260,000 acre-feet flood flows to the Delta every four years, a regular sampling of years does not properly demonstrate this trend.
167. See Glenn et al., supra note 13, at 19;
168. LUECKE ET AL., supra note 13, at iv.
169. Under the baseline, virtually any flow that reaches the Delta will be in excess of 260,000 acre-feet because these flows are the result of flood control events.
170. In reality, there is some non-zero probability that the Shortage alternative will not supply flow in each year. However, this probability is too small for this study to accurately measure.
171. Stromberg, supra note 43, at 17-19.
172. Durations greater than four years appear at the far right of the cumulative distribution function for the System Release and Banking alternatives. These are a result of the initial historical conditions at the beginning of the period of study, and in the case of the Banking alternative, the initial period required to accumulate sufficient water banked to make a flood release. Under normal operation, the maximum period without a flood in both these scenarios is four years.
173. This study did not use enough years to draw any conclusion about the specific probability of periods longer than 60 years. However, even 60 years without water would devastate the ecology of the Delta.
174. See Pitt et al., supra note 1, at 821.
175. See supra note 65.