Technical Assessments in Support of the Edwards Aquifer Science Committee "J Charge" Flow Regime Evaluation for the Comal and San Marcos River Systems

Mark Hamilton
Jim Boeing


Since the 1970s, the Edwards Aquifer Authority (EAA) and its predecessor agency, the Edwards Underground Water District (EUWD), have operated and maintained four recharge dams located on the recharge zone of the Edwards Aquifer (Aquifer) in Medina County. These structures were constructed by the EUWD on private properties through negotiated easement agreements with landowners within the Nueces River and San Antonio River basins for the purpose of artificially enhancing natural occurring recharge to the Aquifer. The Edwards Aquifer Authority Act (Act) further recognized the aquifer’s recharge capability by granting the EAA the authority to enter into cooperative contracts with political subdivisions of the State of Texas for artificial recharge and to own, finance, and construct recharge dams. To date, however, there have not been any new dams constructed. Over time, with the advent of new technologies and improved understanding of the hydraulic nature of the Aquifer, the EAA “Recharge Program” has evolved beyond the concept of enhanced recharge (or dams) and has developed into a more comprehensive initiative focused on enhancing the available yield of and protecting the water quality in the Aquifer. As a result, today, enhanced recharge is only one of a multitude of tools available to the EAA in its mission to optimize the yield and protect the long-term sustainability of the Aquifer for its beneficial use. Accordingly, this report is presented to communicate the updated scope and priorities of the EAA “Recharge Program” as they have evplved over time. Included is background information on the aquifer and its geologic and hydraulic attributes, summaries of various regional supply strategies and, finally, staff recommendations for the program’s future direction. Background information used to develop this document is derived from previous EAA staff presentations to the Board of Directors (two presented as Technical Briefings and three as reports to the Aquifer Management Planning Committee), which are summarized