UPDATE: The Lake Alert for Lake Rowena has been lifted.
The City of Orlando recently tested water samples in Lake Rowena and discovered potentially unsafe concentrations of cylindrospermopsin.
Cylindrospermopsin is a type of cyanotoxin produced by freshwater cyanobacteria/blue-green algae, which is always present in fresh water, but are sometimes able to produce toxins.
The City of Orlando will continue to monitor the water over the next few weeks but until they have more information, water-contact activities should cease until further notice.
Lake Rowena was most recently closed in January for the same reason and again in December following a sewage leak.