Questions or Comments:
You are here:

Aquilla Reservoir: Improving the Quality of Drinking Water Sources

A completed TMDL project to reduce atrazine in Aquilla Reservoir, which is a source of drinking water for several communities. The total maximum daily loads (TMDLs) are adopted and the implementation plan (I-Plan) is approved.

photo of filter strip at edge of cornfield in Aquilla Reservoir watershed
Filter Strip at edge of on a farm in the watershed of Aquilla Reservoir

County: Hill
Parameter: Atrazine
Basin: Brazos River
Segment: 1254

On this page:

Background and Goals

Aquilla Reservoir is a 3,280-acre lake located in Hill County. It was constructed in 1983 for use as flood control, recreation, and as a supply for drinking water treatment facilities. Testing of treated drinking water at a regional treatment facility found high levels of the herbicide atrazine, which pointed to contamination in the lake.

Agricultural sources were the primary contributors to pollution in the reservoir. The goal of the project was to reduce atrazine concentrations in the reservoir to safe levels.

Back to the top of the page Back to top


Atrazine concentrations in Aquilla Reservoir have been reduced to safe levels. Water from the reservoir is sampled at regular intervals to ensure that atrazine concentrations remain at a safe level. Routine tests of treated drinking water continue, and indicate that atrazine is below the criteria used to evaluate its safety for human consumption. For more information about how the goal was achieved, read:

Back to the top of the page Back to top

TMDLs and I-Plan

The commission adopted this TMDL on March 23, 2001; it adopted revisions to the TMDL on June 14, 2002. The EPA approved the TMDL on October 30, 2002, at which time it became part of the state's Water Quality Management Plan.

The commission approved the I-Plan on January 18, 2002.

Back to the top of the page Back to top

For More Information

Please e-mail us at and mention Aquilla Reservoir in the subject line. Or call us at 512-239-6682.

Back to the top of the page Back to top

communities working together taking care of our rivers, lakes, and bays