Union of Concerned Scientists

Florida's largest river, the Apalachicola, along with the Chattahoochee and Flint Rivers in Georgia and Alabama are known collectively as the ACF river system. Together they drain more than 19,000 square miles of watershed to form a delta at the shoreline of the Florida panhandle. The Apalachicola Bay at the mouth of the river system includes areas where extreme changes in salinity occur. The combined effects of river flow, seasonal winds, tides, and the shape of the river basin control these changes.

Biodiversity
Ecosystems of the Apalachicola drainage basin include upland forests, swamps, marshes, and floodplain wetlands. The sections of the watersheds from the Florida panhandle to Mobile Bay support some of the richest biodiversity in all of North America. For example:

• The AFC river system is also known for its diversity of fish, with 85 species. Some species are restricted to the river basins in this central Gulf Coast region, including the striped bass, which occurs only in the Apalachicola River.
  
  
• The flora of the region includes 117 plant species, including 28 threatened and 30 rare species. Nine plant species are found only in the panhandle region, while 27 are found only in the general Apalachicola area.
  
  
• The floodplain forests of this region are home to more than 250 species of vertebrates, not counting fish, and represent one of the most important animal habitats in the Southeast.
  
  
• The highest density of amphibian and reptile species in the country occurs in the upper watersheds.
  
  
  
• Two species of birds, the ivory-billed woodpecker and Bachmans sparrow, are already considered extinct. The barrier islands in this region also provide important habitat for Gulf migratory birds.

Human Pressures
Increased demand for water by large upstream cities such as Atlanta have promoted engineering and water management projects that now divert freshwater resources from the AFC river system. In addition, agriculture extracts well over 300 million gallons per day for irrigation, largely from the Flint River. Massive water consumption by the households and industries of the metropolitan Atlanta region results in very little upstream storage and greatly reduced water downstream of the city. In addition, the water released back into the system from Atlanta is of poorer quality. Small flows from reservoirs are released to dilute urban wastes, mostly from the Atlanta area, to ensure a minimally acceptable water quality. Further reductions in reservoir water levels would threaten a multimillion-dollar recreational industry.

Future changes
The current regulation of river flows by reservoir storage and by intensive water withdrawals has eliminated much of the floodplain and the dynamic habitats it provided for plants and animals. Human consumption of fresh water is expected to continue to increase – likely leading to further reductions of freshwater flow in the Apalachicola Bay system. Future rainfall and streamflow are uncertain. Increased moisture may help to lessen the risk of drying out the area. However, additional climate change-related reductions in rainfall and streamflow would considerably reduce the plant and animal productivity and threaten the unique biodiversity of this region.