Coastal Dune Lakes 

The coastal dune lakes of Walton County are scientifically interesting because of their intermittent connection to the Gulf of Mexico. This periodic connection serves as control for flood-level (relative to structures and associated infrastructure) waters by opening a conduit to the Gulf. When a lake reaches a critical pre-flood level, breaching water forms an outlet (channel) through the dune system and empties the lake water into the Gulf. Depending on tides and weather conditions, saltwater and saltwater biota from the Gulf may fill the lake and any biota voids created by the lowered water level. The drainage of the lake and potential exchange with the Gulf continues until equilibrium is reached and the opening closes. When there is an 5 exchange with the Gulf of Mexico, a brackish water-body is formed.