Walton County officials came together Tuesday afternoon with engineers and contractors to complete the closure of the last coastal dune lake. Crews have used 10,000 cubic yards of sand to protect the lakes that were identified at risk. 

Beaches of South Walton is home to the largest concentration of rare coastal dune lakes in the world. Coastal dune lakes can only be found elsewhere in Madagascar, Australia, New Zealand, and the Northwest Pacific Coast of the U.S.  They are characterized by the intermittent nature of their connection to the gulf.  When the water level, through rain or other inflow, reaches a certain height, the lake will "blow out" and release its water into the Gulf.  At that point, sea water may enter to create an estuary.  After the lake water level subsides, the connection to the Gulf will disappear until the lake is ready to "blow out" once more.  These fragile ecosystems are an important source of freshwater to migrating birds and other beach organisms.

CNN recently reported on these measures.  You can watch the video by clicking here.