Lake Alert for Lake Rowena

January 18, 2022

UPDATED Information- A Lake Alert for Lake Rowena was issued on May 27, 2021 due to a potentially unsafe concentration of toxins present in the lake. City of Orlando Stormwater staff have been continuously monitoring and sampling Lake Rowena 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 performed by City of Orlando staff, sampled directly by Mills Avenue, indicate there is still a trace amount of toxins (cylindrospermopsin) in the lake. We are aware that Florida Department of Environmental Protection (FDEP) took samples from Lake Rowena on 1/6/2022 on the opposite side of the lake, near Leu Gardens, and determined that no toxins were detected. However, due to this discrepancy, Lake Rowena will continue to be closely monitored by City of Orlando staff. The lake will be resampled in late February and, at that time, we will provide another update. At this time, the Lake Alert remains in effect until further notice.

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, will also have the latest information. _______________________________________________________________

On May 27, 2021 the City of Orlando tested water samples from Lake Rowena and determined that potentially unsafe concentrations of cylindrospermopsin are present in the lake. As a precaution, we are advising everyone to refrain from swimming, recreating and irrigating in/from Lake Rowena 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 Rowena. The city staff will continue to routinely test the lake, but the city's tests will only provide an update on the presence of cylindrospermopsin. 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.

Please encourage your neighbors to register for the Lake Alert at so they too will get important information about Lake Rowena directly.

In the meantime, as we stated above, the city would advise refraining from swimming, recreating and irrigating in/from the lake until further notice.

We have attached a link for additional information:

If you should have additional questions, please email Lisa Lotti at

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