Runoff sediment created from nearby construction projects could threaten Taylor Leal’s favorite part of the San Marcos River: its clarity.
Leal, education senior, said she has been a regular at Sewell Park since her freshman year at Texas State. She said the San Marcos River’s quality is one of the reasons so many people flock to Sewell Park to escape the Texas heat.
“People like our river because it’s so clear,” Leal said. “Nobody would want to get in a dirty river.”
Dianne Wassenich, program director for San Marcos River Foundation, said the university and the rest of the town are located around the headwaters of the river. Wassenich said runoff from construction causes sediment to form small “peninsulas” in the San Marcos River. The runoff buries the endangered native to the area and can cause the riverbed, which typically feels gravelly, to feel muddy, Wassenich said.
Wassenich said most of the runoff created on the Texas State campus goes into Sessom Creek.
This is problematic because the creek flows into the head of the river.
The Department of Facilities Planning, Design and Construction is looking into projects to prevent storm water runoff from entering the river. The Environmental Protection Agency additionally has a Municipal Separate Storm Sewer System that attempts to keep the river clean, Wassenich said.
However, in some cases it is difficult to keep runoff from entering the river when it rains, said Michael Petty, director of Facilities, Planning, Design and Construction. He said a recent eight-inch downpour managed to overrun the university’s storm water pollution prevention devices.
Petty said he had contacted University of Texas staff members who oversee storm water protection plans. Petty said he found everyone was in agreement that the only thing that can be done is to use as many protection devices as possible.
“No one can design a protection system for any project to account for an eight-inch deluge,” Petty said. “It’s going to overwhelm any protection devices we have in place. We’d probably have to have a 30-foot dam somewhere along University Drive and a huge lake to capture (runoff).”
Petty said a number of “best management practices” are implemented on construction projects. The practices include examining and immediately repairing silt fences along construction sites, in addition to ensuring storm drains are blocked from runoff.
A storm-water pollution-prevention plan is put in place for each project, Petty said. The information is posted on the project’s site.
“We could have (Texas Commission on Environmental Quality) show up unannounced and want to take a look at our protection devices,” Petty said. “We have to be prepared, and as a general rule, we are prepared.”
Wassenich said it is difficult to remove river pollution once it has occurred, but a new project slated to begin in January could be a major help.
The Habitat Conservation Plan will remove much of the sediment from the river to protect some of the native endangered species. The project will be financed by an additional charge to the Edwards Aquifer pumping fee. Wassenich said the project will also involve replanting wild rice where it may have been depleted.