Sustainability Indicators for Long-Term Water Supply: Case Studies of Tucson Active Management Area

Abstract

Meeting growing water demand is a significant concern in Arizona. Potential future water shortage caused by climate changes and droughts in the Colorado River basin have raised the awareness to save the water whenever it is possible to support sustainable water supply in the future. In order to manage the finite groundwater resources in Arizona, five areas relying on mined groundwater were identified and designated as Active Management Areas (AMAs). The primary management goal of the AMAs is so-called “safe-yield”, which is accomplished when no more groundwater is being withdrawn than is being annually recharged. In general, groundwater overdraft is used as an indicator to measure sustainability, which is simply the difference between the annual amount of groundwater withdrawn and the natural and artificial recharge in the basin. Although a water budget measure provides a broad overview of a water usages and supplies in a geographically delineated area, it is clear that more specific indicators are needed to help those who are engaged in evaluating the alternative water management plans with respect to sustainability of supplies. This study focuses on developing water resource sustainability indicators. Then a wide range of water conditions and management scenarios will be evaluated using the developed measures based on the data and projection of Tucson Active Management Area (TAMA).