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by Kirsten Sorensen, Cleanups and Research Programs Manager

KTB has had the honor of managing an EPA Grant through their Trash Free Waters program since 2020, extending project funds throughout the state to different organizations working to prevent the flow of litter into the Gulf of Mexico. 

On December 5th, Kirsten Sorensen, KTB’s Research and Cleanups Program Manager, traveled to San Marcos to spend time with Amy Thomaides, Community Enhancement Initiatives Manager at the City of San Marcos, to learn more about the projects that the city has implemented to prevent litter from reaching the San Marcos River. 

Gabion Walls at an Interstate Truck Stop

The best way to keep our waterways clean is to prevent litter from reaching it in the first place. This is the idea behind the gabion wall installed at a popular truck stop off the IH-35 corridor in San Marcos. 

The parking lot of the truck stop backs up to Willow Creek, one of the five local creeks that directly feed into the San Marcos River. The volume of trash that accumulates in that parking lot is significant. A walk through the area very quickly demonstrated how much litter is caught by the gabion wall, a simple structure made from rebar, rock, and wire. 

While the gabion wall traps the litter, the problem remains that large-scale cleanups are still necessary to remove accumulated trash from the site.

Children’s Educational Activity Book 

To promote long-term behavioral change in the community, San Marcos worked with a local artist to create a 42-page educational activity book for children. The book takes you on a guided two-mile walk of the San Marcos River with Sally the Salamander and Freddy the Fountain Darter. Activities completed along the way include drawing three pieces of trash and following the river map to see how that trash winds up in the Gulf of Mexico. It also provides education on how trash in stormwater runoff enters the river. When the activity guide passes through one of the many parks, it provides information on microlitter (such as pinatas and confetti from birthday parties) that also remain in the environment and wind up in local waterways. 

LittaTraps in Downtown Storm Drains

Finally, the city used the funds for this project to expand on an already successful initiative to capture trash from the downtown area before it enters the river. Currently, the City of San Marcos has 10 LittaTraps installed in storm drains. These baskets are placed inside of storm drains, and allow water to filter through while capturing anything solid that travels through. 

The first quarter these 10 LittaTraps were installed yielded 400 pounds of captured trash, all of which would have otherwise wound up in local waterways. 

The City of San Marcos has done a fantastic job of implementing a range of solutions to protect their local waterways, and KTB is grateful to have partnered with them on this project!

As our EPA Trash Free Waters grant draws to a close, this concludes Kirsten’s site visits to our project partners. For more information about these projects, visit, or see posts on her other site visits: STOP Audit in Houston with Keep Pasadena Beautiful and Black Cat GIS, Keeping Trash out of Houston Waterways with the Buffalo Bayou Partnership, and Preserving Habitat and Ecosystems with the Galveston Bay Foundation.