Crews begin treating Lady Bird Lake to reduce toxic algae

The City of Austin is continuing its efforts towards reducing toxic algae in Lady Bird Lake.

Crews were out bright and early Monday applying lanthanum-modified clay at three locations on Lady Bird Lake.

This process is part of a five-year pilot program to reduce harmful algae blooms on the lake. It targets reducing the growth of algae that can get people sick and be fatal to dogs.

"Unfortunately, in 2019, there were a number of dogs that passed away after interacting with the water, with algae mats and a couple of areas of Lady Bird Lake," said Dr. Brent Bellinger, Conservation Program Supervisor with the Watershed Protection Department.

How it works is, crews will apply a lanthanum-modified clay to parts of the lake. The clay then bonds to phosphorus, the harmful algae’s prime food source, and makes it unavailable, essentially starving the algae.


"As we've done for the past three years, we kind of do treatments throughout the summer period. When the cyanobacteria are, you know, basically trying to do their most growth, and we're trying to inhibit that as best we can by limiting the availability of phosphorus," said Dr. Bellinger.

This is year four of the program, and the Watershed Department reports the last three years of results have been mixed. At Red Bud Isle, the modified clay has been working and there has been less harmful algae growth. However, by I-35, the clay is not having much of an effect.

Dr. Bellinger says there is still time to analyze and research mitigation techniques and technologies before the program is up.

"The search never stops. There's never just one solution. This is a start, and we'll go from there," he said.