AWWA SOURCES66470

Tucson Water, the largest municipal water provider in southern Arizona, is engaged in a dialogue with the community regarding the long-term sustainability of its water supply. The basis for this exchange is Water Plan: 2000-2050 which was developed to inform the community and decision makers about the water-resource challenges that lie ahead. Until recently, the City of Tucson and all other water users in the greater Tucson region relied almost exclusively on groundwater pumping to satisfy water demand. Over time, the regional aquifer has been overdrawn resulting in declining ground-water levels, measurable aquifer compaction and land subsidence, and environmental degradation. Given that Tucson Water's current service area population of about 750,000 is projected to perhaps double by 2050, decision makers recognize that the Utility's continuing dependence on groundwater for supply cannot sustain the community in the longer term. The Plan identifies the need to implement a three-fold water management strategy to address current supply issues and to prepare for the future. This strategy emphasizes more aggressive demand management, supply augmentation, and the full utilization of available renewable water supplies. The renewable source waters that are currently available are imported Colorado River water and locally-generated municipal effluent. The community, in partnership with Tucson Water, will make a series of threshold water-resource decisions in the coming years. The Plan decisions will focus on how best to utilize the renewable supplies since each presents unique challenges and uncertainties with regard to treatment, operational flexibility, and supply reliability. The decisions will also have a bearing on broader sustainability considerations beyond just the long-term availability of water supply. The Utility's future demand for energy, potential large-scale land usage impacts, air quality issues, water usage efficiency, and several other sustainability criteria must be considered to provide an appropriate context for decision-making. Includes 10 references.