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UPDATE: Lake Alert LIFTED for Lake Arnold

Orlando seal

June 15, 2022

LIFTED: Lake Alert for Lake Arnold

Based on the latest results from City of Orlando staff sampling Lake Arnold on June 15, 2022, the Lake Alert for Lake Arnold has been lifted. At this time, there are no toxins present in Lake Arnold, but blooms may still occur. There are always risks that could be associated with swimming, recreating, or irrigating in and from water with algal blooms, please use your own caution. If you see a visible bloom present, please report it to the FDEP Algal Bloom Dashboard, which can be found here: floridadep.gov/AlgalBloom.


Prior Lake Alerts follow:

UPDATED Information – A Lake Alert for Lake Arnold was issued on February 25, 2022, due to a potentially unsafe concentration of toxins present in the lake. City of Orlando Stormwater staff have been continuously monitoring and sampling Lake Arnold since the Lake Alert was issued. This message is to provide an update on the status of the lake.

The results from the latest sampling event on May 18th, 2022, indicate there are no toxins present in the lake at this time. However, out of a preponderance of caution, the City is electing to keep the Lake Alert in effect to ensure the bloom subsides and the lake does not produce additional toxins. The lake will be resampled in June, and once the results are obtained, we will provide another update.

Please continue to call the Lake Alert number, 407.246.2220, for the most up-to-date information regarding your lake. During weekdays, the City's Lake Alert website, orlando.gov/lakealert will also have the latest information.

Algae FAQs


On February 25, 2022, the City of Orlando staff tested water samples from Lake Arnold and determined that potentially unsafe concentrations of toxins are present in the lake. As a precaution, we are advising everyone to refrain from swimming, recreating and irrigating in/from Lake Arnold until further notice.

For reference, cyanobacteria/blue-green algae are always present in the water, however, not all bacteria have the ability to produce toxins. Toxicity is hard to predict because a single species of algae can have toxic and non-toxic strains. Nothing can be done to treat algae blooms without causing massive fish kills. Due to this, the city will work closely with Florida Department of Environmental Protection (FDEP) to closely monitor Lake Arnold. The city staff will continue to routinely test the lake, but the city's tests will only provide an update on the presence of toxins. The official toxin determination is obtained from FDEP's laboratory data, and until the levels are deemed safe by state standards, the Lake Alert will remain in effect.