San Antonio Water System’s board of trustees approved an agreement Tuesday that makes way for the densest development Helotes Canyon has seen yet, albeit with concessions meant to protect the Edwards Aquifer Recharge Zone, which is downstream from the canyon.

After hearing opposition from more than a dozen residents, environmental advocates and the City of Grey Forest during its meeting, SAWS agreed to provide water for up to 3,000 homes within a new planned subdivision in Helotes Canyon, northwest of San Antonio.

In the agreement, SAWS lists nine concessions the developer, Lennar Homes of Texas, must meet to help protect the Edwards Aquifer, the vast limestone rock layer that holds the largest source of drinking water in the San Antonio region.

Since last year, Lennar Homes has been planning to build a 3,000-home subdivision on a 1,160-acre property within Helotes Canyon called the Guajolote Tract. Based within SAWS extraterritorial jurisdiction, Helotes Canyon is one of the most environmentally sensitive areas when it comes to the security of San Antonio’s drinking water supply, according to a study by the Southwest Research Institute, which found development could cause severe environmental impacts on the aquifer.

During the public comment portion of Tuesday’s meeting, Greater Edwards Aquifer Alliance Executive Director Annalisa Peace said while the alliance appreciates the efforts of SAWS staff in negotiating more protective measures for the aquifer, and recognizes SAWS is required to provide water service within its area of operations, it still requested the SAWS board deny the utility service agreement.

“This request for denial is based on our perception that supplying Guajolote with water to serve 3,000 [homes] on this tract is inconsistent with the need to protect San Antonio’s Edwards Aquifer water supplies,” Peace said. “We are concerned that stormwater pollution and wastewater effluent disposal make this area unsuitable for high-density development.”

A map shows the boundaries of the watershed of the San Antonio River (blue line) layered over the Edwards Aquifer Recharge Zone (dark blue) and Contributing Zone (light blue).
A map shows the boundaries of the watershed of the San Antonio River (blue line) layered over the Edwards Aquifer Recharge Zone (dark blue) and Contributing Zone (light blue). Credit: Courtesy of San Antonio River Authority

Other environmental advocates offered similar comments. Representing the local chapter of the Sierra Club, Alan Montemayor said the amount of water the developer is seeking is not sustainable. Montemayor added the amount of planned development does not follow the guidelines outlined in San Antonio’s 2010 North Sector Plan (although technically the document has no legal bearing on the new subdivision since it is located outside the city limits).

Per the new agreement, Lennar Homes must set aside half of the project’s acreage as open space, must restrict the subdivision to 30% impervious cover —  any type of man-made surface that doesn’t absorb rainfall — and cannot use any Texas Commission on Environmental Quality-approved wastewater treatment plant permits to serve development outside the 1,160 acres it is already planning.

Additional stipulations state that should Lennar Homes decide to build a sewage treatment plant for the development, the plant must meet all TCEQ standards for facilities discharging within 5 miles of the Edwards Aquifer Recharge Zone, and must include increased sewage treatment requirements.

Peace said the alliance would contest any application Lennar submits to the TCEQ to build a sewage treatment plant that would discharge treated wastewater into the waterways that recharge the Edwards and Trinity aquifers, such as Helotes or Chiminea creeks. 

Under SAWS’ Certificate of Convenience and Necessity (CCN), the utility is required to provide water service upon request. Because of this, SAWS Trustee Amy Hardberger said the water utility should consider amending its CCN to perhaps not include land outside San Antonio’s direct city limits.

“This is another example of my ongoing frustration that SAWS is positioned as the gatekeeper for land development and land use, which we actually don’t have authority to be,” Hardberger said. 

Peace told the San Antonio Report she was glad to see SAWS staff note it may also contest a sewage treatment plant permit for the development, should Lennar Homes decide to go that route. Peace added while the alliance would rather see no high-density development in the area, if Lennar does proceed, it would prefer septic systems since they require half-acre lots, which would reduce density.

“With SAWS, [Lennar] can develop to a higher density, although we understand their hands are tied, because this is in their water service area and they’re required to give service,” Peace said. “SAWS staff did a good job of putting strict concessions on it.”

Lindsey Carnett covers the environment, science and utilities for the San Antonio Report.