Crooked Lake is located within a closed basin, which means the lake does not recieve flow from other lakes or rivers. Water levels in Crooked Lake, therefore, are highly dependent on rainfall within the watershed.
The Crooked Lake watershed includes two sub-basins. The southern sub-basin is known as Little Crooked Lake. When the lake level exceeds approximately 114 feet NAVD88, the two sub-basins are hydrologically connected. When water levels fall, such as during a drought, the two sub-basins form two distinct water bodies.
When water levels exceed approximately 119 feet NAVD88, water can discharge from Crooked Lake south into Lake Clinch. However, the canal between Crooked Lake and Lake Clinch is located on private property and not regularly maintained. Therefore, vegetation growth and erosion can impede water flow during high water levels.
The slope of the lake bottom is highly variable, with the northern lobes of the lake reaching depths of over 30 feet, and the southern lobes being less than 20 feet deep. The area of the lake can change substantially with changes in water level.
Minimum Flows and Levels
The Southwest Florida Water Management District establishes MFLs to protect the nature of Crooked Lake
In 1972, the state of Florida created 5 water management districts to regulate water use and facilitate water resource planning across the state. The district responsible for most of Polk County, including Crooked Lake, is the Southwest Florida Water Management District (SWFWMD). When an organization (e.g. a farm, a municipal water utility, factory, etc.) wants to construct a well and start pumping water out of the ground, they must first apply to SWFWMD for a Water Use Permit. The permit application process requires that the applicant demonstrate that they will not have a negative impact on existing legal users or nearby surface water bodies. To facilitate this process, SWFWMD establishes minimum flows and levels (MFLs) for water bodies throughout the district. According to Florida Statutes (Section 373.042(1)(b)), the minimum water level of a surface water body is defined as “…the level of surface water at which further withdrawals would be significantly harmful to the water resources of the area.” Therefore, if a water body is currently meeting its MFL, a water use permit applicant must demonstrate that their water use will not cause a water body to fall below its MFL. If a water body is not currently meeting its MFL, water use permit applicants must demonstrate no impact on the water body.
There are four components to the MFL established for Crooked Lake:
High Guidance Level – The elevation that a lake’s water levels are expected to equal or exceed ten percent of the time on a long-term basis – 120.47 feet NAVD
High Minimum Lake Level – The elevation that a lake’s water levels are required to equal or exceed ten percent of the time on a long-term basis – 119.67 feet NAVD
Minimum Lake Level – The elevation that the lake’s water levels are required to equal or exceed fifty percent of the time on a long-term basis – 116.67 feet NAVD
Low Guidance Level – The elevation that a lake’s water levels are expected to equal or exceed ninety percent of the time on a long-term basis – 114.87 feet NAVD
Water Level Data
Water levels are recorded approximately monthly by SWFWMD. The gauge is located near the boat ramp at Bob’s Landing. The chart below shows water levels recorded since approximately 1982.