Austin Battles Harmful Algae with Clay Treatment in Lady Bird Lake

Austin, once again, confronts the dreaded blue-green algae in its greenbelts and waterways that propose acute health threats to both humans and pets alike. In a bid to fight this menace, the city has started applying a specialized treatment plan to crucial parts of Lady Bird Lake just this week.

What is more striking is that this particular treatment is not a new experiment. It marks the fourth consecutive year in a five-year pilot program aimed at examining the potency of this method.

The Treatment Explained

The treatment administered to the water parts incorporates a unique type of modified clay. This clay has a strong affinity for phosphorus present in the water, binding with it, and then settling at the bottom of the lake. The underlying motive is to deprive the algae of its primary food source- phosphorus. Without phosphorus, there will be a significant reduction in algae growth.

Efficacy Status

However, the proof of the pudding lies in its eating. Thus far, the treatment results have been mixed, and more or less uneven. The areas treated east of I-35 continue to document high algae levels despite the clay treatment, whereas the area around the Red Bud Isle has shown a slight improvement. This site has reportedly recorded a decrease in algae growth at the onset of summer.

Yet, it seems the city is locked in a cat and mouse game with the algae that refuses to bow down completely. Despite recording early success, the algae resurfaces each year post-treatment in this area.

On-site Process

With the commencement of another week, contractors have begun the clay treatment. The target areas for the application include around the Red Bud Isle, the boat ramp on the north shore of Lady Bird Lake, and the stretch between I-35 and the lagoon present behind the Festival Beach Boat Ramp.

The application process involves spraying a gray slurry into the lake that eventually clouds the water temporarily. Though safe, it is advised that recreational boaters should maintain a safe distance from the barge.

The Blue-Green Algae Problem

Blue-green algae, scientifically known as cyanobacteria, hit the headlines in 2019 after major floods led to an alarming increase in plant nutrients in the water. This, in turn, triggered the growth of blue-green algae in the lake. Ever since then, these algae have disturbed the otherwise serene life by initiating health hazards for Austin residents and becoming a fatal threat for several pets.

The Contributing Factors

City scientists point out that the root cause of the increasing algae levels lies in the fertilizer runoff from nearby lawns alongside upstream agriculture. Septic waste, too, contributes to the surge. Environmental factors such as warming temperatures and recurring droughts further add fuel to the fire, thereby favoring the algae’s growth.

In light of these developments, officials have urged the local residents to actively participate in mitigating the situation. They can do so by limiting the use of fertilizers on their lawns and diligently picking up pet waste. Furthermore, they should refrain from entering the water or allowing their pets to do, especially when it is still or warm, or when a visible film of algae covers it.

Despite being a popular spot for dogs to cool off, swimming in Lady Bird Lake is not permitted for humans.