A look at the River Authority’s efforts during the San Antonio River Draining


A Plecostomus species is found in the San Antonio River. | Photo by San Antonio River Authority

You may have heard about the Annual River Draining and the interesting finds discovered at the bottom. But what happens to the fish? We decided to reach out to the experts and find out for you.
Meet the San Antonio River Authority

While the City of San Antonio is responsible for the draining, the River Authority uses this time to perform preventative maintenance + improve the river’s habitat function. This is done by planting aquatic plants, relocating native species, and removing non-native invasive species from the river.

What is the process for relocating the native species?

During the dewatering event, the River Authority’s scientific staff typically rescues those native fish stranded manually and moves them upstream or downstream Think: water + bucket. The river is more than just what you see along with the River Walk and Mission Reach areas — it’s actually 240 miles long.


Turtley cute river rescue. | Photo by San Antonio River Authority

So, what are native species?

  • Largemouth bass
  • Native shiner fish
  • Various species of sunfish
  • Channel catfish

Got it, so what about non-native species?

  • Apple Snail — one of the river’s newest threats.
  • Armored catfish
  • Tilapia
  • Redbreast sunfish
  • Plecostomus, suckermouth catfish — read more on why you shouldn’t dump your aquarium in the river.

How do these non-native species affect the river?

They can cause bank destabilization and damage a lot of the aquatic vegetation due to not having a natural predator.

Now, let’s talk about aquatic plants

Aside from the relocation and removal process, the team at the San Antonio River Authority’s Watershed & Park Operations Department plants pickerelweed, Louisiana iris, broadleaf arrowhead, and yellow water lily to help the river and its species thrive.

What do you mean by thrive?

  • Aquatic plants provide natural filtration for the water.
  • These plants help keep the water cool + provide shade to those habituating the environment as well.
  • The native plants not only provide a habitat resource required by many of the native species, it helps the surrounding wildlife like native birds + pollinators.

The SATXtoday team with the SA River Authority crew. | Photo by SATXtoday team

How can I help the San Antonio River?

You can Be River Proud and take the pledge “Don’t Let Litter Trash Your River” or by becoming a River Warrior Volunteer. River Warrior initiatives involve trash pickups, apple snail monitoring, water quality testing across the watershed, and citizen science.

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