Located 16 miles south of Tallahassee, Wakulla Spring is one of the largest first magnitude artesian springs in Florida and the United States. Wakulla Spring lies within the Edward Ball Wakulla Springs State Park, which has been listed on the Natural Register of Historic Places and is designated a National Natural Landmark. Wakulla Spring forms the headwaters of the Wakulla River, which flows for nearly 11 miles before merging with the St. Marks River. Wakulla springs is historically renown for is natural beauty.  It has been a favorite recreational site and important potable water source for residents of Leon, Wakulla, and surrounding counties. However, the river and springs have not been immune to human impacts. In recent years, they have demonstrated reductions and reversals in flow as well as increased growth of invasive hydrilla and filamentous algae, likely related to increased groundwater withdrawals for urban use.