Laserfiche WebLink
Chapter 5 Direct Economic Impacts <br />A. Hydrology of the San Juan and Animas Rivers <br />Mean biweekly flows present a picture of the seasonal variability of flows on the San Juan and <br />Animas rivers (see Figures 5-A-1 and 5-A-2). The substantial seasonal fluctuations are driven <br />by the accumulation, and subsequent melting of snowfall in Colorado's southern Rocky <br />Mountains. The native fishes of these rivers have declined largely as a consequence of the <br />economic development of the region that has had the effect of altering the hydrology of the <br />rivers (see Maddux et al., 1993). <br />In the grid Southwest, water is a critical factor for economic development. Water is used in the <br />household, factory, and field. Increments and decrements in water quantity and quality and <br />institutional rules governing its use can mean the difference between thriving economies with <br />associated robust ecosystems and stagnant economies with dewatered riparian areas. <br />The economy of the Four Corners region of Colorado, New Mexico, Utah, and Arizona is expected <br />to grow as new immigrants are attracted by its climate, lack of crime, and abundance of recreational <br />activities. This new influx, along with growing agricultural demands for water, will place <br />increasing pressure on the water resources of the San Juan River. <br />The hydrological scenarios include a status quo WOFBA (the Baseline) and a future WF scenario <br />that allows for the recovery of the endangered fishes. The current water conditions were <br />determined by ex ining an historical set of flows for the years 1967 through 1985. The WF <br />scenario was constructed by first calculating the average historical flows then subtracting the flows <br />that USFWS considers necessary for fish recovery. After allowing for current depletion, any <br />rem ining flows are available for future development.13 The details of this analysis are available in <br />Chapter II-6 of Brookshire et al., 1993 <br />13The current research being undertaken through the San Juan Recovery Implementation Program will <br />ultimately determine the flows needed. <br />32 <br />