[ Isaac Lang | Special to the Times ] An aerial view of the river

Franklin County is among the unique communities that have left their natural flood plains undisturbed. Because of this, many flood insurance policyholders in the county benefit from a 15 percent savings. Here's how it works.

Flood plains are important ecosystems and provide benefits that may not be apparent at first glance. Flood plains supply nutrients and habitats for thousands of species in a river system like the Apalachicola River.

A river's flood plain is the broad, flat area that surrounds the main channel; it can stretch for miles on either side. When a river floods, water overflows the channel and spreads onto adjacent land, filling wetlands, sloughs and streams. When high-water levels subside, the river returns to the main channel and flood plain water eventually seeps into the ground or finds its way back to the river.

The Environmental Protection Agency (EPA) estimates a one-acre wetland typically can store about three-acre-feet of water, or about one million gallons. An acre foot is one acre of land, about three-quarters the size of a football field, covered one-foot deep in water.

All rivers naturally experience periodic high-water flows. Flood plains serve as natural reservoirs, slowing and holding floodwaters until water can return to the river channel or be absorbed into the ground, rather than flooding surrounding streets and homes. Wetlands also reduce the velocity of the water and its destructive potential. However, if the river's natural functions are impeded – by development, for example – flooding can result.

The Federal Emergency Management Administration (FEMA) reports that floods are the most common and widespread natural disasters, and recognizes open space as the most effective way of avoiding flood damage. Through FEMA's Community Rating System (CRS) program, communities are rated based on steps a community takes that reduce disasters' impacts.

FEMA rewards communities that do not develop within the flood plain, so it continues its natural functions. A good rating helps residents save money on flood-insurance premiums. Franklin County takes part in the CRS Program and receives a good rating because its flood plain has not been developed and it retains its natural functions. Flood policyholders currently save 15 percent on their flood insurance premiums.

Historically, many cities developed on or near flood plains. These broad, flat expanses are very fertile and attractive to build on during dry conditions. When flooding occurred, cities implemented flood-control measures such as dams, reservoirs and levees. While these measures have been successful in some ways, they have limits.

Recent events have demonstrated the value of a functioning flood plain. When Hurricane Harvey hit Texas, it dumped 60 inches of rain on Houston; an unprecedented nine trillion gallons of water fell over four days. The disaster was worsened because over the past 10 years, thousands of homes were built in the flood plain.

Land once able to hold and slow floodwaters had become suburban neighborhoods and roads. There was no longer a safe place for floodwaters to go. More than 1,600 homes flooded and there were $800 million in insurance claims filed.

The Apalachicola River flows 106 miles from the Florida/Georgia line to Apalachicola Bay, one of the largest undammed rivers in the United States. The river's flood plain is about 144,000 acres, though its width varies along its length – from 400 feet wide in upper sections to 4.5 miles wide in lower sections. Protecting the river's natural forms and functions not only benefits wildlife and water quality but also can help protect our homes.

Anita Grove is a coastal program coordinator with Apalachicola National Estuarine Research Reserve (ANERR), which is managed on a day-to-day basis by the Florida Department of Environmental Protection's Florida Coastal Office. Locally, Franklin County was a key partner in the establishment of this Reserve in 1979.