Name What is a coastal dune lake?
Coastal dune lakes are found within about two miles of the coast. They’re typically shallow and irregularly shaped. They are usually permanent water bodies, but their water levels fluctuate substantially since they create transitory interchanges with the Gulf of Mexico. The lake-water is composed of both fresh and saltwater that comes from tributaries, groundwater seepage (from uplands and from the Gulf), rainfall, exchange with the Gulf, and coastal storm surges. The lake-water is generally colored (e.g., tea or black colored) due to the dissolved organic matter it contains. This is a natural phenomenon, and it’s nothing to be worried about! While these lakes are exposed to normal weather conditions just like any lake, Florida’s coastal dune lakes are also tremendously impacted by hurricane activity (i.e., storm frequency, strength, and duration).
What is an outlet/outfall?
One of the most interesting features of Walton County’s coastal dune lakes is their intermittent connection to the Gulf of Mexico. When a coastal dune lake reaches a relatively high water level, it actually breaks through the dune system and the beach sand and empties into the Gulf of Mexico. The channel that is formed between the lake and the Gulf is known as the lake’s outlet or outfall. Depending on tides and weather conditions (particularly wind), saltwater from the Gulf may enter the lake, along with saltwater plants and animals. The drainage of the lake and potential exchange with the Gulf continues until equilibrium is reached and the opening closes.
Are all of Walton County’s coastal dune lakes the same?
Each of Walton County’s coastal dune lakes has its own personality, based on the combination of its size, watershed features, surrounding land uses, and outlet characteristics. Outlet openings vary greatly in length, frequency and duration. They are driven by each lake’s critical high water level as well as prevailing climatic conditions (e.g., droughts and rain). As a result, some of the dune lakes can be completely freshwater, some brackish, and some salty, with varying degrees of salinity occurring between different lake stages. The changing condition of water chemistry in the coastal dune lakes makes them dynamic, biologically diverse ecosystems.
Logging requirements:
Update: Please message the answers to me but feel free to post your pictures with the log.
1. Observe the water at stage one. Describe the color of the water.
2. Observe the water in the gulf. How is it different from the lake water?
3. Is the outfall of Draper Lake flowing into the gulf today? Take a picture of the outfall or describe it.
4. Name at least 5 of the 15 dune lakes located in Walton County