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112 : WATERLA W REVIEW Volume 5' , IV. COMPA~T ADMINISTRATION ISSUES A. COMPETITIOr:. WITH THE NATURAL ENVIRONMENT Since the inception of the La Plata River Compact in 1922, many of the issues and concerns that served as the impetus to create a defined interstate water flIlocation system have continued to plague the river system. Fore~ost among these problems is the limited amount of water availabltj to serve irrigation demands. This problem is especially acute after th:e spring runoff. As indicated by Article II of the Compact, Coloradoj must deliver one-half of the measured streamflow at Hesperus t9 the state line." Further compounding the difficulty of providing water to the state line is competition among the natural elements. The headwaters of the La Plata River reach 13,000 feet in elevation, the river quickly descends 4,900 feet during its six mile journey to Hesperu~, accompanied by a climatic transformation from alpine to arid-dese~t conditions," The river channel itself is composed of a consorth,lm of cobbles, gravel, and fine sands that promote excessive seepage into the shallow alluvium." Consumptive use from riparian vegetation also affects the delivery of water through the river corridor. Withi/1 the fifty-two miles the La Plata River flows from Hesperus to FarmiNgton, New Mexico, there are an estimated 3,580 acres of riparian/wetland plant communities within the one-mile wide river corridor." The plant species in this area vary in type and density, but the pre<ilominant phreatophyte species include cottonwood trees and willpws, which consume an average of 5.5 feet of water each year." Thefe natural, physical elements can have a dramatic effect on the jdelivery of one-half of the streamflow at Hesperus to the state lin~. For example, during dry periods in the middle to late summer ",hen the streamflows at Hesperus are in the 80-100 cubic feet per second range, the transit losses through the thirty-one mile river corridor to the state line routinely approach 45-50 percent." As the flows continue their decline to a "benchmark" of twenty-five cubic feet pe:r second at Hesperus, the La Plata River streambed often b~come~ completely dry for intermittent stretches above the state line. I 54. Id. 55, See USGS, supra note 11,!at 400. 56. 1 U.S. DEP'T OF INTERIO*, ANIMAS-LA PLATA PROJECT: FINAL SUPPLEMENT TO THE FINAL ENVIRONMENTAL STATEME"[f III.56 (1996). 57. Id. i 58. See MORTON, W. BlTI1NG~R & GLEN, E. STRINGHAM, A STUDY OF PHREATOPHYrE GROWTH IN THE LOWER ARKANSAS RIvERVALLEYOF COLORADO 17 (1963). 59. Report of the La Plata ~ver Compact Administration, prepared by the Division VII Irrigation Engineer 11 (1954). 60. See id.