Systems analysis of upper San Pedro River Basin conflicts

Abstract

A potential for conflict exists over water management and allocation in the Upper San Pedro River Basin. Competing demands for limited water supplies have resulted in concerns about the depletion of the ground-water supplies, reductions in stream flow, and downstream obligations associated with the Gila River Adjudication. A network flow model is an effective tool for analyzing the nature of these water conflicts and evaluating how the introduction of new management strategies can ameliorate the problems. Analysis of water management reveals that concerns about the water problems are valid. Irrigation wells pumping ground water from the floodplain aquifer reduce stream flows that are both necessary for the viability of San Pedro riparian ecosystem, and claimed by downstream Indian tribes. They also contribute to the ground-water overdraft situation in the regional aquifer. Water management alternatives that limit or reduce irrigation consumption are the most effective in rectifying the problems.