HISTORY

Lake Tarpon is the largest freshwater lake in Pinellas County. Because of its historic excellent water quality and rich fish and wildlife resources, the lake has served as a regionally important recreational resource for many decades. The lake was even used for water supply from March 1926 to May 1930.

The lake was formerly tidally influenced from a 118-foot deep sinkhole, Knight’s Sink, on the northwestern shore of the lake. This sink connects with Spring Bayou in Tarpon Springs. The saltwater tidal influence resulted in wide fluctuations of the lake level. In 1967, an earthen dam and outfall canal discharging to Old Tampa Bay were constructed on the southern shore.  Two years later, the Southwest Florida Water Management District (SWFWMD) built an earthen dike around the sinkhole leaving the outfall as the only point of discharge and eliminating tidal and saltwater influence.  Construction of the outfall canal and sinkhole dike made the levels more controllable, which was especially important during storm events.

In July 1969, part of the dam in the south canal was removed for high water discharge, and by 1971 the dam was replaced with gated culverts. In 1972, SWFWMD adopted and implemented a controlled lake level fluctuation schedule.

In the summer of 1987, Lake Tarpon suffered a major bloom of blue-green algae that covered 80% of the lake. The bloom persisted for much of the summer and severely impacted recreational and aesthetic use of the lake during the prime recreational season. Extremely low dissolved oxygen concentrations were noted in several residential canals and minor fish kills were reported. As a result of the perceived ecological degradation, Pinellas County, responding to concerned local citizens, petitioned SWFWMD to place Lake Tarpon on the list of priority water bodies to be remediated under the newly enacted Surface Water Improvement and Management (SWIM) program. In late 1987, Lake Tarpon was designated by SWFWMD as the seventh ranked SWIM priority water body.

In addition to the actions of SWFWMD, the Pinellas County Board of County Commissioners passed a Special Resolution in July of 1987 creating the Lake Tarpon Management Committee. The intent of the Resolution was to create a multi-agency committee to formulate a "Plan of Action" whereby a long term lake management plan would be developed and implemented for Lake Tarpon. In October of 1998, the Lake Tarpon Drainage Basin Management Plan, prepared for Pinellas County by PBS&J consultants (PBS&J, 1998), was released.