How does the Savannah River contribute to Georgia's economic growth? A The Back River and Middle River feed into Savannah's National Wildlife Refuge. B Because of its location, the Savannah River is one of the busiest ports for trade in the United States. C The Savannah River forms the eastern boundary between Georgia and South Carolina that contributes growth. D Since it is dammed in three places, the river forms Lake Hartwell, Lake Russell and Lake Thurmond that contribute to growth.