EDWARDS AQUIFER(S): CHALLENGES TO SUSTAINABLE DEVELOPMENT AND USE

The Cretaceous Edwards Aquifer System covers vast areas of Texas. The Balcones Fault Zone Edwards Aquifer is the most important portion of the system that sources Texas’ largest springs, supplies water to over 2 million people, and supports agricultural, industrial, and recreational users, but it faces major challenges for sustainable use. First, despite over a century of studies, important facets of aquifer geology, hydrology, and ecology need elucidation. Tracing studies have shown the importance of karst conduit system on aquifer performance, which has led to revision of aquifer boundaries and quantification of groundwater flow rates and directions, which are needed for effective resource management including siting of wells and response to incidents of contamination. Ecological studies have revised knowledge of aquifer species and re-categorized endangered species resulting in the need for ecosystem protection. Second, new challenges are arising. Population along the Balcones Fault Zone is predicted to double by 2050 with increased water demands and accompanying urban alterations of the hydrologic system, including new types of degradation. The effects of climate change, particularly on aquifer recharge, are difficult to predict, but we expect more prolonged droughts as well as severe rainfall events. Finally, water law and policy are changing with groundwater becoming a property in situ, which may make it more difficult to manage groundwater pumpage. Despite these formidable challenges, there are new technologies (e.g., ASR, desalination, use of DNA, multiport wells, etc.), new management strategies (e.g., habitat conservation programs), and continually improving numerical models that can address many of these challenges. Aquifer management will have to be flexible to adjust to new data, demands, laws, and technologies.