Guenther and Euclid Retrofit

Through Clean Water Act Section 319(h) Grant Funding from the Environmental Protection Agency (EPA), the Texas Commission on Environmental Quality (TCEQ) and the San Antonio River Authority (River Authority) have entered into the Upper San Antonio River Watershed Protection Plan (WPP) Implementation – Green Stormwater Infrastructure Master Plan contract. 

The Guenther and Euclid Stormwater Retrofit Project allows the River Authority to implement demonstration stormwater retrofits. The low impact development (LID) best management practices (BMPs) utilized for this project are identified in the Upper San Antonio River WPP. 

The San Antonio River Basin’s primary source of pollution is non-point stormwater runoff. LID is a set of stormwater BMPs that addresses stormwater runoff. LID treats small, frequent storm events on-site with a focus on “first flush” pollutants. These are pollutants such as oils, pesticides, E. coli bacteria, and other constituents that, under a traditional site-to-street-to-stormdrain-to-creek stormwater conveyance system, wash off hardened surfaces and into our streams. LID also reduces the volume of runoff generated on a site, thereby reducing pollutant loading to the waterbody. 

Demonstration BMPs were constructed in accordance with the River Authority's LID Technical Guidance Manual, and provide case studies of highly urbanized construction retrofits. At the River Authority’s headquarters on 100 E. Guenther St., permeable pavers, bioretention areas, and cisterns address pollutant export that flows directly into the San Antonio River. At the River Authority’s Environmental Center, 600 E. Euclid Ave., a series of rain gardens that run the length of the building, currently collect one third of the rooftop runoff. Two 22-foot tall cisterns were added to collect the remainder of the building’s rooftop runoff and are used in an onsite irrigation system. 

The demonstration BMPs installed through this project have become a public education tool on how retrofits and LID can reduce storm water runoff and non-point source pollution.