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Are recent Lake Lanier algae blooms toxic? Samples show levels 'not extreme'
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Recent heavy rains have brought algae blooms, like this one in Flat Creek, to Lake Lanier. The Lake Lanier Association is testing to find out whether the algae is toxic. (Photo courtesy of Lake Lanier Association)

Updated at 2:14 p.m. on Nov. 4: Toxins were present in algae test samples, but “the levels were not extreme,” Lake Lanier Association President Jennifer Flowers said Wednesday, Nov. 4.

“Technically, if you go by recreation standards, it’s still safe to recreate in the cove, though we don’t suggest that,” she said. “People need to watch out where they’re swimming and if they see any discolored water or algae blooms, they need to avoid that area.”

Also, she asked if anyone sees potential algae blooms to email the association at lakeinfo@lakelanier.org.


Algae has shown up in at least a couple of places on Lake Lanier’s shoreline since heavy rains earlier this month, and the Lake Lanier Association is urging people to be careful around the lake while an algae sample is tested for toxicity. 

“This growth is likely due to the amount of nutrients washed into the lake from the heavy storms,” the association said in a newsletter this week. “Additionally, the sunlight and the heavy debris layer impeding water movement have likely made ideal circumstances for growth.” 

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Recent heavy rains have brought algae blooms to Lake Lanier. The Lake Lanier Association is testing to find out whether the algae is toxic. (Photo courtesy of Lake Lanier Association)

Some 2 million gallons of raw sewage flowed into Flat Creek during the heavy rains, with testing showing significantly high levels of bacteria in the water downstream from the spill. The spill took place after a pump failure at Gainesville’s Flat Creek Water Reclamation Facility, and Lake Lanier Association President Jennifer Flowers said that spill may have contributed to the algae spotted in Flat Creek in West Hall. 

The algae has also been spotted in waters at Laurel Park off Cleveland Highway/U.S. 129 in North Hall, but it could be in other areas of the lake as well, Flowers said. 

“Make sure that the water in the area you will be using is free of discoloration, abundant algae growth debris build up or any odors,” the Lake Lanier Association newsletter warns residents. “If you see any areas of algae growth … ensure that your pets (and you) do not enter the water.” 

The group is expecting test results from algae samples in 7-10 days, Flowers said Thursday, Oct. 23. 

“There are many different kinds of algae species, from harmless greens to cyanobacteria, which is the cause of blue-green algae,” according to the newsletter. “There is always the thought that it might be blue-green algae when seeing this vibrant of a green bloom. 

“However, there are many species that can cause this, and even if it is blue-green algae, not all blue-green algae blooms produce toxins or cause problems.” 

Blue-green algae “can be harmful when the toxins it produces in air and water reach concentrations that are dangerous to people, marine life and the environment,” according to a Centers for Disease Control and Prevention website

People may encounter potentially harmful algae by swallowing contaminated water, eating seafood contaminated with toxins, breathing in toxins that are in air particles or through direct contact, such as swimming or boating, according to the CDC. 

Exposure can cause such problems as nausea, vomiting, diarrhea, sore throat, pneumonia, dermatitis and conjunctivitis, the agency says. 

Blue-green algae usually multiplies and blooms “when the water is warm, stagnant, and rich in nutrients (phosphorus and nitrogen) from sources such as fertilizer runoff or septic tank overflows,” according to the CDC. 

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Recent heavy rains have brought algae blooms to Lake Lanier. The Lake Lanier Association is testing to find out whether the algae is toxic. (Photo courtesy of Lake Lanier Association)
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