Coastal dune lakes are bodies of water near the coast that are separated from the larger seawater by naturally occurring sand berms. These bodies are shallow, irregularly shaped and mostly freshwater. Even though their water levels fluctuate substantially, coastal dune lakes are usually permanent water bodies. The lake-water looks black or tea colored due to the dissolved organic matter it contains. This is nothing to be worried about, and is naturally the way the dune-lakes appear. For more information, you can visit the conservatory’s website that protects these rare phenomena found in Walton County, Florida.