Nutrias have invaded the San Antonio River Walk. These freshwater beaver-like creatures that are also commonly referred to as swamp rats or coypu and SARA Watershed and Park Operations Manager Kristen Hansen confirms that they have been spotted along the Mission Reach parts of the River Walk. This have also been sightings at the low water crossing at Padre.

Nutria is semi-aquatic rodents that live on 2 ½ – 3 ½ pounds of vegetation per day. They’ve recently been enjoying vegetation along the banks of the San Antonio river, causing them to erode over time. Nutrias are comparable in size to beavers, but unlike their long-toothed counterparts, they have long, round, and scaly tails that are filled with bristles. Nutrias also breed quickly and cause their population to increase at alarming rates.

Hansen says “They arrived in North America in the 1930′s as a fur-bearing species and since then, they have spread to cover the eastern two-thirds of Texas as well as many other states,” Since they are an invasive species, SARA has hired specialists to place traps along the river to catch them. Then once they’re trapped, they’ll be “euthanized in accordance with Texas Parks & Wildlife Department.”

In 2020, there have been less than 10 swamp rats trapped on the banks of the River Walk. If you spot a nutria along the banks, you can report it to the San Antonio River Authority at (866) 345-7272 or on the SARA website

The damage that nutrias could cause to the River Walk may be irreversible which is why Hansen explains that “As the agency responsible for the maintenance of the Mission Reach segment, it’s important that we address any challenges to the well-being of the project for the safety and enjoyment of the general public. Our staff worked to find an appropriate solution to the damage caused by the Nutria-rat population in an effort to preserve the project’s ecosystem and the health of the San Antonio River.”