HR: 16:30h
AN: H34B-03    [Abstracts]
TI: Integrated Modeling of Water Policy Futures in the Imperial-Mexicali Valleys
AU: Kjelland, M K
EM: mkjelland@hotmail.com
AF: Texas A&M University, Dept. of Wildlife and Fisheries, 210 Nagle Hall, TAMU 2258, College Station, TX 77843 United States
AU: * Forster, C B
EM: forster@arch.utah.edu
AF: University of Utah, College of Architecture+Planning, 375 S. 1350 E., Rm 235, Salt Lake City, UT 84112 United States
AU: Grant, W E
EM: wegrant@tamu.edu
AF: Texas A&M University, Dept. of Wildlife and Fisheries, 210 Nagle Hall, TAMU 2258, College Station, TX 77843 United States
AU: Collins, K
EM: kcollins@mail.sdsu.edu
AF: California Center for Border and Regional Studies, Sandiego State University, Imperial Valley Campus , 720 Heber Avenue, Calexico, CA 92231 United States
AB: Divided by an international border, the Imperial-Mexicali Valleys (IMVs) are linked by shared history, natural resources, culture and economy. This region is experiencing changes driven by policy makers both within and outside the IMVs. The largest external decision, the Colorado River Quantification Settlement Agreement (QSA) of 2003, opens the door to a laboratory for studying the consequences of a massive transfer of agricultural water to municipal users. Two irrigation districts, two urban water agencies and the State of California have agreed to a 75 year of more than 30 million acre-feet of Colorado River water from agricultural to urban use. Although Imperial Valley farmers will be compensated for water conservation and land fallowing, the economic, environmental and social consequences are unclear. Farmers who fallow will likely cause a greater impact on local businesses and government than those choosing on-field water conservation. Reduced agricultural water use causes reduced flow of irrigation runoff, at higher salinity than before, to the Salton Sea that, in turn, impacts the population dynamics of Ichthyan and Avian species at the Salton Sea. Municipal wastewater discharged into the New River by Mexicali, Mexico is also an important source of inflow to the Salton Sea that will be reduce by plans to reclaim the wastewater for various uses, including cooling water for two new power plants in the Mexicali. A restoration program is funded to produce a Sea with much reduced surface area. But this approach may, in turn, lead to increases in windblown dust from the dry lakebed that will contribute to an air basin already designated as a federal nonattainment area for particulate emissions. Additional water will be conserved by lining the All American and Coachella canals. But, eliminating seepage from the All American canal reduces groundwater recharge to aquifers used by Mexican farmers. A complex interplay of water-related issues must be accounted for if planners and residents of the IMVs are to make sound socioeconomic and environmental policy decisions. We use a spatially-explicit, stochastic, simulation compartment model (based on difference equations with a daily time step programmed with STELLAr software) to simulate the hydrologic system that underlies our broader modeling of the socioeconomic and environmental future of the IMVs. Alternative future scenarios are defined and used to explore the hydrologic and environmental implications of variations in future Colorado River flows, and various water-related policy decisions. The results of a suite of simulations, made assuming that the Sea is not impounded in small sub-Seas, suggest that the salinity of the Salton Sea is most likely to continue increasing. If this is the case, and if restoration of the Salton Sea continues to be a high priority, then more aggressive water conservation methods or a much smaller Salton Sea will be required. More aggressive conservation will lead to greater socioeconomic concerns, while a smaller Sea will increase concerns regarding windblown dust from the exposed lakebed.
UR: http://www.borderplus20.sdsu.edu/
DE: 6334 Regional planning
DE: 1803 Anthropogenic effects
DE: 1812 Drought
DE: 1884 Water supply
SC: Hydrology [H]
MN: 2004 AGU Fall Meeting