Guadalupe River water diversion discussed

Bill West, general manager with the Guadalupe Blanco River Authority (GBRA) on Tuesday gave Gonzales County Underground Water Conservation District (GCUWCD) board members details of a draft permit that would enable the Guadalupe-Blanco River Authority (GBRA) to divert up to 75,000 acre-feet of water from the Guadalupe River for storage for later use.

The permit, which would allow GBRA to divert water from the unappropriated flows of the Guadalupe River and use that water for municipal and industrial purposes anywhere within GBRA’s 10-county statutory district, is being published for public comment.

GBRA’s objective is to monitor water resources in the rapidly developing Central Texas region that includes Caldwell, Hays, Comal, Guadalupe and Gonzales counties. The executive director of the Texas Commission on Environmental Quality (TCEQ) submitted the application.

The permit application is part of GBRA’s planned $400 million Mid-Basin Project, which may include the use of both surface and groundwater. The project is included in the recommendations in the 2011 South Central Texas Regional Water Planning Group’s endeavors in the State Water Plan.

“We filed the application for the permit in December 2009 because we wanted to be proactive in addressing the demand being created in the high-growth areas of our basin,” West told the board. “Between 2000 and 2010, the total population of those five counties has increased from 315,455 to 455,269 — an increase of more than 44 percent.”

Development of the project comes from the input of 25 stakeholders in the GBRA area of responsibility over the proposed impact on environmental flows (or “e-flows”), a figure implemented to monitor stream flow and inflow to estuaries and bays in Texas.

“We developed this project and its related permit application with the understanding that it would need to meet criteria established by the SB-3 e-flows process,” West said. “After a lengthy and thorough review, TCEQ’s staff concluded the project would meet all of the requirements and standards put in place by the state, and thus issued the draft permit.”

West advised the board that despite the fact that the permit calls for 75,000 acre-feet, the eco-flow restrictions would restrict any diversion to about one-third of that amount.

Additionally, the permit would authorize construction of one or more off-channel reservoirs that would have a combined storage capacity of up to 125,000 acre-feet. With TCEQ’s e-flow requirements shown in the permit, the project’s actual yield is expected to be at least 25,000 acre-feet per year. The off-channel reservoir(s) would be constructed somewhere in Gonzales County.

Board member Barry Miller said the GBRA might have underestimated the potentially high price tag that could come with acquiring land for a diversion point, mainly due to the Eagle Ford Shale “oil boom.”

Miller also told the board that the project would have some impact on the underground district, since the GBRA proposal is to reroute the surface water and store it underground.

“We’re going to have to do something with our rules about how you recover that water,” he said.

The permit application is currently in its 30-day comment period, which continues through the end of August. Comments about the draft permit should be sent to TCEQ Chief Clerk Bridget Bohac.