Patsy Glenn Refuge Rainwater Harvesting System

Patsy Glenn Refuge.jpg

On October 21st, the Wimberley Birding Society and the Hays County Master Naturalists in partnership with the Meadows Center for Water and the Environment and the Wimberley Valley Watershed Association sponsored a rainwater harvesting demonstration workshop at the Patsy Glenn Refuge in Wimberley. This demonstration workshop also marked the installation of the first of many best management practices (BMPs) for the Cypress Creek Watershed Protection Plan (CCWPP).

The Wimberley Birding Society, which created the Patsy Glenn Refuge, recognizes the importance of protecting the aquifer while also developing the landscape of the natural area. Earlier this year, they decided to replace the aquifer supplied irrigation system for the butterfly garden with a rainwater harvesting system to eliminate demand on the aquifer. This rainwater collection structure and harvesting system was designed and installed to achieve this goal.

This collection structure and rainwater harvesting system was designed to provide irrigation water for the butterfly garden at the Patsy Glenn Refuge during the seven-month period from April through October in order to keep plants in bloom during the dry summer months.  Up to 192 gallons of rainwater can be harvested from the 16’ x 20’ roof for every inch of rainfall. The three 500-gallon plastic tanks connected in tandem can store up to 1500 gallons at a time. If future monthly rainfall amounts match historical averages, this system can provide up to 800 gallons of irrigation water per month from April through October, assuming that the tanks are full at the end of the winter. Furthermore, since the butterfly garden is downhill from the storage tanks, irrigation water is delivered to the garden via gravity so no pumps or other mechanical devices are required. The total material cost of the post and beam collection structure and the rainwater harvesting system is estimated to be $3,000 (not including donated posts, roofing and guttering), and it took about 230 hours of volunteer labor—with a value of $5060—in order to build it.

The structure and system located near the northeast corner of the Wimberley Community Center parking lot was designed by Jim McMeans. The chosen design for the rainwater harvesting system blends in very well with the natural surroundings at the Patsy Glenn Refuge.

The CCWPP Rainwater Harvesting Resource Guide as well as other handouts that included a sketch of the collection structure and system, materials list, rainwater harvesting calculations, and video of the workshop are all posted on the Patsy Glenn Rainwater Harvesting System page on our website.

To learn more about the CCWPP, please visit

This cooperative project was supported in part by the United States Environmental Protection Agency through the Texas Commission on Environmental Quality.