On April 20, 2023, City Council approved Resolution No. 20220609-066 to initiate variances and amendments to the Land Development Code, including site-specific amendments to Chapter 25-8, Subchapter A, Article 13 (Save Our Springs Initiative), as necessary to allow for the completion of the Little Bear Aquifer Recharge Enhancement Project, an aquifer recharge project at Stoneledge Quarry within the Barton Springs Segment of the Edwards Aquifer.

The Edwards Aquifer is a federally-designated, sole-source aquifer, which serves as a primary source of drinking water for tens of thousands of people and is a vital resource to the general economy and welfare of the City of Austin and the State of Texas.

Through land purchases and conservation easements, the City of Austin now protects over 33,000 acres of land in the recharge and contributing zones of the Aquifer to benefit water quality and quantity. In 2002, the City of Austin used Open Space Bond Funds to purchase an 86.4 acre tract within the Edwards Aquifer Recharge Zone (“Wenzel Tract”) in northern Hays County that includes the 18 acre Stoneledge Quarry. The purchase of the abandoned Stoneledge Quarry was in partnership with the Hill Country Conservancy for the purpose of constructing the recharge enhancement facility.

The Little Bear Creek Recharge Enhancement project proposes to divert a portion (30% to 50%) of the flood flows above 50 cubic feet per second from Little Bear Creek though a diversion channel into Stoneledge Quarry, where the water will slowly recharge the Aquifer thereby increasing aquifer storage and enhancing flows at Barton Springs; Exhibit 2.

The upstream drainage area to the proposed diversion channel is approximately 7,000 acres, of which 42% (approximately 2,900 acres) is protected from future development by fee simple and Conservation Easement purchases and includes the Ashmun, Nester, Hays County Ranch and Cypress Water Quality Protection Lands.

Summary of Proposed Code Amendment:

The amendment under consideration is related to an enhancement project for the Edwards Aquifer currently under review that is located within the Edwards Aquifer portion of the Barton Springs Zone. A portion of the proposed diversion channel described in SP-2022-0462D is within the Critical Water Quality Zone (CWQZ) of the site. The SOS Ordinance prohibits development in the CWQZ for areas within the Barton Springs Zone and would not permit the construction of this facility.

Additionally. The SOS Ordinance requires non-degradation water quality treatment for all development within the Barton Springs Zone. WPD engineering staff are verifying whether any modification to the non-degradation water quality requirement will be needed to construct the project prior to Environmental Commission and Planning Commission.

Because 25-8-515 prohibits variances from the SOS Ordinance, a site-specific amendment to the SOS Ordinance approved by a supermajority of the City Council is necessary to allow construction of the Little Bear Creek Recharge Enhancement Facility.

Five variances are also necessary to complete the site development permitting process:

  • 25-8-211 (Water Quality) to allow natural vegetated filter strips or alternative water quality controls to provide water quality treatment in the Barton Springs Zone.
  • 25-8-263 (Floodplain Modification) to allow floodplain modification within a CWQZ.
  • 25-8-341 (Cut) and 25-8-342 (Fill) to allow cut and fill in excess of 4 feet.
  • 25-8-482 (Water Quality Transition Zone) to allow development in a water quality transition zone that lies over the Edwards Aquifer recharge zone in the Barton Springs Zone.

The project is proposing to use natural vegetated filter strips as the primary water quality control with the goal to meet SOS non-degradation water quality standards to the maximum extent technically feasible. Additionally, construction of the Little Bear Creek Recharge Enhancement Facility will require floodplain modification within the CWQZ and development in the WQTZ to construct and connect the diversion channel from Little Bear Creek to the quarry and allow for the diversion of flood waters as proposed. The grading associated with the channel construction also requires cut and fill in excess of 4 feet. Mitigation for impacts associated with the development will be provided in excess of minimum code requirements.

Review and Adoption Timeline:

Case Manager Contact 

Scott Heirs, Watershed Protection Department,