A preliminary feasibility analysis of artificial recharge in the Avra Valley, Arizona, with Santa Cruz River flood flows

Abstract

This study is a preliminary assessment of the physical and economic feasibility of recharging the Avra Valley, Arizona, aquifer with water from Santa Cruz River flood flows. At least two sites within Avra Valley are suitable for aquifer recharge through injection wells. The annual mean flow of the Santa Cruz River for 1946-1976 was 15,300 acre-feet with a coefficient of variation of .94. During this same period, the river was dry an average of 310 days a year. These hydrologic conditions make water storage necessary for a continuous supply. A three-compartmented reservoir system with a total volume of about 57,000 acre-feet was designed for this purpose. This system allows for continuous withdrawal of water for recharge amounting to about 15,000 ac-ft/yr, by minimizing evaporation losses to about 30 percent. Economic analysis includes cost estimates of pipelines, reservoirs, and land purchases, resulting in a total annual capital cost per acre-foot of about $80. This cost is of the same order of magnitude or less than the projected cost of imported Central Arizona Project water.