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Lake Hall at Maclay Gardens
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Photos and article by Dr. Sean E. McGlynn
McGlynn Labs, Inc.
Surface Area: 172 acres
Classification: Oligotrophic
Location: Tallahassee Hills
Lake Hall has the best water quality in Leon County and the greatest clarity of all our lakes. There is persistent speculation that it is spring fed, but no flow or issue of spring water has been discovered, yet from the sheer clarity of the water one is inclined to believe that the water must come from the aquifer. Lake Hall is not connected to the aquifer via an open sinkhole, as it did not drain during the drought of 1999-2001. There have been reports of a submerged cavern in the southern lobe of the lake near Maclay Gardens, and there are numerous Karst depressions in and around Lake Hall.
The beds of Vallisneria americana and Sagittaria stagnorumin Lake Hall are reminiscent of what Wakulla Springs was before it was taken over by the invasive exotic, Hydrilla verticillata. Hydrilla has been found growing in Lake Hall in late 2000; the aquatic flora may be changing. A very heavy growth of Hydrilla found in a small karst depression within the eastern lobe of Lake Hall was treated with time release Sonar. Grass Carp were released into Lake Hall by FDEP in 2001 in an effort to control this invasive exotic. No Hydrilla was found in Lake Hall in an aquatic plant survey in 2003.
Occasional algal blooms are a natural occurrence in our subtropical Florida lakes; however, persistent blooms are indicative of problems. During the past eleven years, Lake Hall has experienced four such algal blooms, most recently in September 2003. This algal bloom was confined to the eastern lobe of Lake Hall near where the Hydrilla was found. Lake Hall rose 3 feet after the March rains of 2003 which finally brought lake levels to a full pool. The water level rise may have caused the die-back of aquatic vegetation that had colonized deeper parts of the lake during the drought when water levels were lower. With the rise in water levels, less light reached these plants, and they began a slow die-back. By late October 2003, the bloom had subsided and the floating vegetation was gone. The floating mats of plants also cut off the light to the submerged vegetation growing under them, causing them to die back too. These algal blooms are a warning that our lakes are fragile resources that need to be protected for the enjoyment of future generations.
During the summer of 2003, there were problems with bacterial levels in Lake Hall near the swimming area, and area was closed to swimming. Once the swimmers were away for a few days, bacterial levels returned to normal and the swimming area was reopened.
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