Crooked Lake Water Quality


A summary of the factors affecting water quality in Crooked Lake

Crooked Lake has a reputation for excellent water quality, which contributed to its designation as an Outstanding Florida Water by the Florida legislature. One of the primary roles of the Defenders of Crooked Lake is help protect and maintain the water quality of Crooked Lake through public education and collaboration with local stakeholders on water quality improvement projects. Volunteers from the Defenders of Crooked Lake also support our understanding of Crooked Lake's water quality by collecting water samples as part of the Florida LAKEWATCH program.

While Crooked Lake's water quality has historically has been excellent, we must remain vigilant to keep Crooked Lake clean and beautiful for future generations. The following are the broad categories of pollutants that threaten Crooked Lake:


All lakes in Florida are susceptible to eutrophication - excess algae growth as a result of too much nutrients in the water. The typical culprits are nitrogen and phosphorus. For Crooked Lake, the primary concern is nitrogen. Figure 1 shows the relationship between nitrogen concentrations in Crooked Lake and concentrations of chlorophyll-a (a proxy for algae). As concentrations of nitrogen increase, the potential for algae blooms also increases. Figure 2 shows the concentration of nitrogen in Crooked Lake since samples have been collected.

Sources of nitrogen in Crooked Lake include direct runoff from lawns and other fertilized areas, septic tanks and wastewater systems within the watershed, and atmospheric deposition (i.e. nitrogen that falls with the rain). As the watershed continues to develop, the sources of nitrogen that threaten Crooked Lake will increase.

Artificial Chemicals

Artificial chemicals - such as herbicides, pesticides, petroleum fuels and lubricants, etc. - are widely used in our watershed. Each chemical can be a threat to the plants and wildlife of Crooked Lake.


The combination of steep grades and heavy rainfall is a dangerous combination in the Crooked Lake watershed. As rainfall runoff picks up speed, it also picks up sediments and carries it downhill to the lake. This can lead to a reduction in water clarity and infilling of the lake. Controlling stormwater runoff is an important part of water quality management throughout the watershed.


Crooked Lake Chlorophyll vs. Nitrogen relationship Crooked Lake Total Nitrogen Concentrations

Further reading: