Coastal dune lakes are lakes that occur in coastal communities along the Gulf of Mexico. The lakes are rare ecosystems only found in the Florida Panhandle, Madagascar, Australia, and New Zealand. They are freshwater systems that intermittently exchange water with the Gulf of Mexico through a meandering outlet. The periodic opening and closing is what makes coastal dune lakes so unique. Lake Powell is the largest coastal dune lake in Florida, holds the coveted “Pristine Florida Waterway” designation, and is a special Carillon Beach amenity.