DEP's Florida Geological Survey to Conduct Dye Trace at Porter Hole Sink, Lake Jackson

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CONTACT: DEP Press Office, 850.245.2112,

DEP's Florida Geological Survey to Conduct Dye Trace at Porter Hole Sink, Lake Jackson

TALLAHASSEE, Fla. – On Saturday, Aug. 14, 2021, the Florida Geological Survey (FGS), in coordination with the Northwest Florida Water Management District, will introduce a non-toxic fluorescent dye into Porter Hole Sink. Currently, Porter Hole Sink is exposed on the dry lakebed of Lake Jackson due to a dry down event. This dry down event offers a unique opportunity to study where the water in Lake Jackson goes once it drains into the underlying upper Floridan aquifer.

The upper Floridan aquifer provides drinking water to the citizens of Leon and Wakulla counties and is also the source of water that discharges from springs like Wakulla Spring.

"One of the goals of this dye trace is to confirm the results of a previous dye trace that revealed there may be a connection between Lake Jackson and Wakulla Spring," said acting Florida Geological Survey Director and State Geologist Guy Means. "Confirming this connection will help resource managers develop more informed strategies for managing our water resources."  

To conduct this study, geologists will introduce bright green fluorescein dye into the sink. This is the same dye used in Chicago every year to turn the Chicago River green in celebration of St. Patrick’s Day.

A total of 23 sites have been chosen to monitor for dye where hundreds of water samples are expected to be collected. Once the dye is introduced through Porter Hole Sink, the sites will be monitored until dye is detected.

Saturday is a perfect time to release the dye due to the low water conditions at Porter Hole Sink and the approach of Tropical Storm Fred. Any rainfall from the storm should help the dye disperse into the underlying aquifer and provide some additional pressure forcing the dye to move toward the sampling sites. It may be weeks or months before the results of this dye trace are known.

Learn more about the Lake Jackson Aquatic Preserve and dry down events