Edwards Aquifer

Currently, approximately 80 percent of drinking water used by SAWS customers comes from the Edwards Aquifer. The Edwards Aquifer Authority (EAA) issued water rights through an established permitting process, and today, SAWS has access to approximately 50 percent (284,000 acre-feet*) of those rights.

Access to these permitted groundwater withdrawal rights is subject to varying levels of availability depending on drought restrictions. These cutbacks in any given year may range from 0 percent to 44 percent. SAWS assumes a firm yield of approximately 113,000 acre-feet during worst-case drought conditions.

This wonderful resource has been the mainstay for this community since its inception, and SAWS continues to review other opportunities in which it can maximize its allocations of the Edwards supply.

Learn more about the Edward aquifer.

Edwards Aquifer Management

In 1993, the Texas Legislature created the EAA to manage groundwater withdrawals from the Edwards Aquifer and provide for appropriate springflow during drought periods. The EAA implemented a permitting system based on historic use of the Edwards Aquifer and regulates and limits withdrawals from the Edwards Aquifer during periods of drought.

In 2007, the Texas Legislature passed Senate Bill 3, establishing a regional pumping cap of 572,000 acre-feet* of Edwards Aquifer withdrawals. Senate Bill 3 also incorporated restrictions on withdrawal limits during drought periods, making these restrictions state law. In addition, the Texas Legislature prescribed a Recovery Implementation Program (RIP) for the Edwards Aquifer region. The RIP identified and evaluated methods to protect threatened and endangered species associated with the Edwards Aquifer, as required by state and federal law. After much deliberation, the RIP stakeholders recommended, and the EAA and other parties ultimately approved, the Edwards Aquifer Habitat Conservation Plan (EAHCP).

SAWS will be playing a significant role related to the EAHCP. This effort is a proactive plan to balance all the human interests which depend on the Edwards Aquifer, San Antonio’s cornerstone water resource, and the Federal Endangered Species Act. The plan allows human interests to co-exist with the protection and recovery of endangered species dependent on Edwards Aquifer springflows. The passage of this EAHCP by the U.S. Fish and Wildlife Service (USFWS) was a major new chapter and will play a key role in the protection of the Edwards Aquifer for all stakeholders and future success can be built off this action.

The EAHCP will be in place until 2027; however, the necessity to balance the needs of the human users of the Edwards Aquifer and the federally-listed threatened and endangered species associated with it will remain. Some form of aquifer management for periods of record-breaking drought will be required to continue. While those future forms of aquifer management can’t be predicted, SAWS has chosen to continue to represent the EAHCP commitment beyond the expiration of the present EAHCP.

In addition to these developments, in 2011 the ratepayers of the former Bexar Metropolitan Water District (BMWD) voted to incorporate the district into SAWS. In the first quarter of 2012, the final state and federal clearances were obtained, and SAWS assumed responsibility for all aspects of the former BMWD. The former district brought with it its own portfolio of Edwards Aquifer water rights, which are now included in SAWS’ water resources portfolio.

Reducing Reliance on the Edwards Aquifer

In contrast to the previous plan’s goal of maintaining an Edwards Aquifer inventory of 295,000 acre-feet* and acquiring an additional 10,900 acre-feet*, SAWS’ 2017 Water Management Plan assumes a maintenance level of approximately 281,000 acre-feet*. This will be achieved through a variety of procurement methods, including buying, leasing and/or a potential dry year option. Through the non-renewal of yet-to-be-determined Edwards Aquifer lease agreements SAWS will significantly reduce its reliance on the Edwards Aquifer. The reduction in Edwards Aquifer inventory allows for a more successful implementation of the flow protection measures identified in the EAHCP.

Managing this wonderfully prolific, highly variable resource is one example of making San Antonio waterful.