AUSTIN (KXAN) — The City of Austin says it’s safe again to be in the water along the Barton Creek Greenbelt.
Austin’s Watershed Protection Department said there has been a “significant” drop in toxin levels in the water near Sculpture Falls after the department issued a warning Sept. 9 about “concerning levels of cylindrospermopsin.” That’s one of several cyanotoxins that can be produced by blue-green algae.
The department said while it’s possible for higher levels of the toxins to return in the water, levels right now are much lower than they were in the fall. At its height, toxin readings were 81 micrograms per liter in September. The Environmental Protection Agency recommends the levels be no higher than 15 micrograms per liter. Two consecutive readings in October were 0.1 and 0.01 micrograms per liter, the department said.
If the flow drops, that’s when the toxins could return, the department said. The toxins thrive in warm, stagnant water, so people should still avoid being in the water or have their pets in the water if it looks stagnant or if mats of algae are visible. The department also recommends people don’t swim “a few days” after heavy rainfall when bacteria levels are typically higher.
After recent testing in other areas, the department said there are still toxins present in Lake Austin at the Walsh Boat Landing near Jessica Hollis Park and in Lady Bird Lake at Festival Boat Ramp.
Symptoms of exposure to the toxins in humans are stomach pain, headache, muscle weakness, dizziness, vomiting, diarrhea or liver damage. Dogs are more susceptible to the toxins, the department said. If dogs are exposed to them, symptoms include excessive drooling, vomiting, staggered walking, difficulty breathing, convulsions and liver failure.
In June, the city signed a five-year contract with SePRO Corporation for $1.5 million to help combat blue-green algae. It uses a phosphorus-binding compound that has been shown to reduce the effects of cyanotoxins, and the pilot program is being done around Red Bud Isle.
For more information on blue-green algae and how the city is trying to manage it, go to the city’s website.