AUSTIN, Texas — This week, Austin Watershed Protection will begin spraying clay on areas of Lady Bird Lake to stop the growth of toxic algae. It's the the second time they've done so this year.
This comes as Watershed Protection officials say they’ve observed an increase in potentially toxic algae mats at Red Bud Isle and Auditorium Shores.
The department started a five-year pilot program applying lanthanum-modified bentonite to the areas afflicted with toxic algae. Dr. West Bishop, the algae scientist and water quality research manager for EutroPHIX, the company contracted for the pilot program, said the goal is to is starve the cyanobacteria.
“We know they crave this nutrient called phosphorus,” Bishop said. “What our treatment does is it grabs the phosphorus first, and we permanently bind up that phosphorus so those cyanobacteria can’t grab it and use it to grow.”
Bishop said the increase in toxic algae blooms on Austin’s lakes could be due to several factors, including the weather.
“Average temperatures are increasing, these really unique dynamic weather events of more extreme rain events, versus longer periods of drought can all promote nutrient flushes that come in,” Bishop said.
Fertilizer and storm water runoff, as well as leaky septic systems, can also lead to an increase in nutrients for the toxic algae.
Over the past few years, some Austinites – like Greg Wright-Crowe, who has lived in the city for almost 30 years – have noticed a change.
“I used to paddleboard up until two years ago because it just got, the shore just got too nasty with too much algae,” Wright-Crowe said.
Easing the concerns of some Austinites about the water quality is something Bishop hopes EutroPHIX is able to help with.
“They’re afraid of using this resource, so my vision is to unite people behind this common goal of being able to use the water without fear,” Bishop said.
On Monday, the Watershed Protection will spray clay in the Red Bud Isle area, the boat ramp on the north shore of the lake just west of Interstate 35 and the north shore of the lake between I-35 and the lagoon behind the Festival Beach Boat Ramp.
The pilot program’s budget is $30,000 for five years, from 2021 through 2025.