By Kevin Wheeler, Timothy M. Magee, Terrance Fulp, and Edith A. Zagona, Proceedings of the NRLC Allocating and Managing Water for a Sustainable Future: Lessons from Around the World, Boulder, Colorado, June 2002

Abstract: The Colorado River has a long history of litigation over a limited water supply. Projected increases in water consumption and recognition of environmental needs will lead to further litigation unless a consensus of interested parties can be reached. Recent developments in computer modeling suggest a way of reaching such a consensus on sustainable policies that could be transferred to other river basins. The United States Bureau of Reclamation (Reclamation) has modeled the Colorado River within a general modeling environment, RiverWare, developed at the Center for Advanced Decision Support for Water and Environmental Systems (CADSWES) at the University of Colorado at Boulder under joint sponsorship by Reclamation and the Tennessee Valley Authority. The Colorado River model includes the existing policy, frequently called the “Law of the River.” The structure of RiverWare allows policies to be extended and modified easily by model users. This flexibility in modeling alternative policies, combined with graphical comparison of the results, has led to the evaluation of a wide range of alternative policies by Reclamation, CADSWES, and several environmental groups. Rapid comparison of policy alternatives has led to generating improved alternatives that better balance the multiple uses of the river. Recent studies include:

• Interim Surplus Guidelines for developing a strategy to decrease California’s dependency on surplus Colorado River water
• Secretarial Implementation Agreement to analyze the effects of water transfers and potential inadvertent overrun withdraws as proposed in California’s Quantification Settlement Agreement and Reclamation’s Inadvertent Overrun Policy
• Secretarial Implementation Agreement to analyze the effects of water transfers and potential inadvertent overrun withdraws as proposed in California’s Quantification Settlement Agreement and Reclamation’s Inadvertent Overrun Policy
• Multiple Species Conservation Program, designed to conserve habitat and work toward the recovery of threatened and endangered species, while accommodating future water and power development
• The impact on water users of alternative plans for supplying sustainable flows to restore biodiversity in the Colorado River Delta
• The operation of the Flaming Gorge Dam to simulate natural flow patterns and meet minimum flow recommendations and consumptive use demands.