Woodcreek Dam on Cypress Creek

On July 6th, Hays Trinity Groundwater Conservation District (HTGCD), Meadows Center and Aqua Texas staff visited the location of a collapse feature on Cypress Creek at Woodcreek North, reported to have formed July 3rd. Furthermore, the dam has three iron sewage pipes, including one that is decommissioned, passing underneath operated by Aqua Texas, Inc. Subsequently, Aqua Texas staff conducted a dye test upstream of the collapse feature, and after 30 seconds the non-toxic dye emerged into the pool on the downstream side of the dam from two locations. Through observations, we infer that the water flowing into the collapse feature is emerging downstream of the dam and is unlikely to be recharging the Trinity Aquifer. Rather, the collapse feature is the result of structural damage (undermining of the dam) in the base of the dam which is now allowing water from Cypress Creek to flow underneath rather than pooling behind it. Samples collected upstream and downstream of the dam show that bacterial levels were not exceeding state standards.

Location of the collapse feature on Cypress Creek, as of July 6th.


Aqua Texas staff poured dye into feature upstream of dam. The dye emerged 30 seconds later downstream of dam.

Channel widths of emerging dye.

As of July 23rd, report of a small hole on the downstream side of the dam and of individuals dumping additional gravel, concrete, etc. in the collapse feature upstream of the dam was received. A sample of water discharged out of the small hole on the downstream side of the dam yielded very high results for bacteria (too numerous to count ~ 2000 CFU/mL). County staff have been routinely monitoring water quality near the dam and all results have been well below the State's standards for bacteria, The County will continue regular sampling/monitoring.

Collapse feature on Cypress Creek, as of July 23rd.

Small hole located downstream of the dam, as of July 23rd.

The Texas Commission on Environmental Quality, Guadalupe Blanco River Authority, and HTGCD have no jurisdiction over the structure, but Texas Parks and Wildlife Department is prepared to assist if a spill occurs. The County is acting as lead and is working with the owner of the dam to determine the best path forward. The Meadows Center is providing support and compiling information. Read more about the collapse feature, here. For more information, please also contact Hays County Development Services.