The San Antonio Water System (SAWS) serves a population of over two million and is among the largest water utilities in the United States. The Edwards Aquifer is a major sole-source karst aquifer in south-central Texas and has historically been the City of San Antonio’s primary water supply. In the year 2000 at the turn of the twenty-first century, the SAWS was almost completely reliant upon the Edwards Aquifer. Nearly a quarter century later, SAWS has established a robust and diversified water supply portfolio designed to ensure a sustainable and reliable supply in a region marked by fast-paced growth, shifting land use, and escalating climate-related impacts.

SAWS has realized decades of water supply progress by optimizing local and regional sources and implementing innovative water management strategies and technologies through multi-stage projects and long-term resource planning. After more than two decades of supply diversification from the Edwards Aquifer, SAWS has access to thirteen water supply projects from seven different water sources. This includes the development and operation of the nation’s largest direct recycled water system, the largest groundwater-based Aquifer Storage and Recovery (ASR) system, a state-of-the-art brackish groundwater desalination plant, and the largest operating water public-private partnership (P3) in the nation. SAWS was also the first utility in the United States to implement integrated resource recovery by beneficially reusing treated effluent as recycled water, biosolids as compost, and digester gas as natural gas achieving an award-winning environmental trifecta through the transformation of wastewater residuals into high-value resources.

These innovative initiatives, coupled with SAWS’s commitment to a proactive and holistic approach to sustainable, long-term water resource planning and management, address critical challenges facing both the city and the broader region by enhancing drought supply reliability, supporting optimal utilization of groundwater withdrawal permits, and augmenting downstream environmental flows that sustain native ecosystems. A truly resilient water system is one that is diversified in its sources, secure in its delivery, and sustainable in its long-term management. SAWS’ resource management strategy leverages innovative and diversified, alternative supplies to maximize production efficiency, mitigate demand variability, and reinforce adaptive system resilience amid evolving socio-environmental conditions. Collectively ensuring a more resilient, diversified, and sustainable water future.