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<br />000342 <br /> <br />DRAFT-Not for distribution <br /> <br />ECOLOGICAL WATER FLOWS FOR THE COLORADO RIVER DELTA <br />UNDER INTERNATIONAL AND DOMESTIC LAW <br /> <br />I. Background; Contemporary Concern Over the Colorado Delta <br /> <br />The Delta of the Colorado River, containing about 150,000 acres of vegetative habitat in <br />Mexico, has become the focus of increasing local, regional and international attention during <br />recent years. Its riparian, wetland and estuarine ecozones are regarded to be of significant <br />environmental importance, 1 among other things for their support of several species variously <br />listed by Mexico as threatened and endangered.2 Part of the area was designated by Mexico as <br />the Biosphere Reserve of the Gulf of California and Delta of the Colorado River in 1993.3 It was <br />the subject of a May, 2000 joint declaration, aimed at cooperative research and coordination, by <br />the U.S. Department of the Interior and the Mexican Secretariat of Environment, Natural <br />Resources and Fisheries.4 It is the subject of Minute No. 306 of the International Boundary and <br />Water Commission signed in December of2000 that seeks coordinated ecological study of its <br />riparian and estuarine resources.s In the spring of2002, the National Human Rights Commission <br />in Mexico reportedly called for environmental enhancement of the Delta out of concern for the <br />Cucapa Indians. 6 <br /> <br />According to one set of estimates being circulated in 2001, the ecological flows needed <br />for the riparian corridor from Morelos Dam to the junction with the Rio Hardy are 50,000 acre- <br />feet of perennial flow and, to regenerate trees, 260,000 acre-feet every four years.7 Currently, no <br />protocols are in place to provide such flows on a predictable basis. In the past eight decades the <br />hydrologic regime in the Delta has been dynamic, due to upstream U.S. and Mexican <br />development and diversions, as well as climatic cycles. Reservoir spills in the 1980s and and <br />flood control releases in the 1 990s, for example, spurred regeneration in the flood plain. At other <br />times the net flows passing through or returning below Morelos Dam have been less than the <br />estimates given above. To the east of the riparian corridor lies the Cienega de Santa Clara, <br />created and maintained to date by bypass drainage waters from the Wellton-Mohawk Irrigation <br />and Drainage District. <br /> <br />Mexico received an average volume of 2 million acre feet of "excess" water during the <br />period 1983-1999, that is, water beyond 1.7 million acre feet per year, with significant excess <br />deliveries in 1997, 1998 and 1999. That excess water was put to beneficial use in Mexico by <br />watering areas within the Colorado River Delta, thus avoiding environmental deterioration. <br />Environmentalist political comment, litigation,8 and published articles9 decry the waning-surplus <br />environmental condition of the Colorado River Delta. 10 <br /> <br />Growing political concern about this problem resulted in the adoption by the International <br />Water and Boundary Commission of Minute 306, II a "conceptual minute," under the authority of <br />the 1944 Water Treaty,12 in December 2000. Minute 306 first recognized that "each country has <br />laws and regulations concerning the preservation of riparian and estuarine system habitat that are <br />executed by authorities that are provided such responsibility in their respective country" and that <br />"collaboration is growing between those authorities as well as between scientific, academic and <br />non-government organizations in the two countries which have an interest in preserving the <br />Colorado River delta ecology.,,13 Minute 306 then recognized a need for the creation of a <br /> <br />1 <br />