In their natural, undeveloped state, floodplains play an important role in flooding. They allow flood waters to spread over a large area, reducing flood velocities and providing flood storage to reduce peak flows downstream. Natural floodplains reduce wind and wave impacts and their vegetation stabilizes soils. Where natural cover acts as a filter for runoff and overbank flows, water quality is improved, and the amount of sediment transported downstream and the impurities in that sediment are minimized. Floodplains can be recharge areas for groundwater and reduce the frequency and duration of low flows of surface water.

Floodplains with Animals

They provide habitat for diverse species of plants and animals, some of which cannot live anywhere else. Floodplains are particularly important as breeding and feeding grounds. Natural floodplains also moderate water temperature, reducing potential harm to aquatic plants and animals.

Local Natural Floodplains

Some local natural floodplains in St. Augustine and St. Johns County are the Guana River State Park and Anastasia State Park. Guana River State Park has beaches, salt marshes, mangroves, tidal wetlands and other habitats. The reserve is an important calving ground for the endangered North Atlantic Right Whale and is home to peregrine falcons, bald eagles, and the endangered Anastasia Island beach mouse. Anastasia State Park also has beaches, tidal salt marshes, and marine and upland hammocks.