The Big Drink
In an effort to provide best practices for the long-term management of storm water in the Edwards Aquifer recharge zone across South Central Texas and to improve UTSA’s ability to remove pollutants from storm water runoff, the university is taking on a project to upgrade storm water management facilities on its Main Campus.
The university will use low impact development to treat runoff from 9 1/2 acres of its rooftops and parking lots, reducing the amount of pollutants entering waterways around the campus. These surfaces often contain contaminants such as oil, bacteria, fertilizers, gasoline, and sediment. Heavy rains compound the impact, washing contaminants into the water supply. A three-year, $1.06 million grant through the City of San Antonio’s Edwards Aquifer Protection Program will help fund the project.
“When the Main Campus was constructed in the early 1970s it was designed to move storm water off site as quickly and efficiently as possible using the best practices in the industry at the time,” says Brian Laub, assistant professor of environmental science, who is leading the project with Janis Bush, professor and chair of UTSA’s environmental science and ecology department, and Mei Lani May, a senior environmental planner in the university’s facilities office.
When the campus first opened storm water was conveyed away from the property through a system of storm drains and open swales that lead to Leon Creek. Modern development of the campus, however, necessitates a new approach. Drawing on the principles of low impact development, the university will use nature as a model to remove the pollutants from storm water at its source. Low-impact development features scattered throughout the site will conserve natural areas, maintain the natural flow of water wherever possible, capture water to let it seep slowly into the ground, and filter out contaminants as it recharges the Edwards Aquifer.
“Today, of the estimated 93,300 square feet of combined rooftop surface for the Physical Education building and the Convocation Center, which both opened in 1975,” May says, “only 0.13% of the storm water is directed to a vegetated area before going through the storm water system via rooftop drains and a French drain.”
The university will retrofit rooftops from the Physical Education, Student Union, and H-E-B Student Union buildings and a portion of the sidewalks, streets, and parking lots in the area with water quality treatment.
To assess the impact of the upgrades, the team will collect water quality samples from storm water runoff before and after the construction project to determine the effectiveness of treatment facilities to remove pollutants. If the facilities prove successful, the project will serve as a model for designing other storm water projects throughout San Antonio and across the aquifer recharge zone.
The project will also provide UTSA’s science and engineering students with a classroom-to-career learning opportunity. Faculty and staff involved in the project will collaborate to provide an outdoor classroom that will provide education and academic research on low-impact development, benefitting Edwards Aquifer water quality by increasing the number of students studying water quality issues specific to the aquifer.
“We are using this project as a living laboratory,” Bush says, “to allow students, faculty, staff, and local community members to learn what we can do as a community to ensure our water source is protected. And we will be collecting valuable data on water quality that can be used in the future to inform management decisions.”