The Cahaba River is Alabama’s longest remaining stretch of free-flowing river and a global treasuretrove of biological diversity. It is the primary drinking water source for one-fifth of the state’s people in the Birmingham metro area. Flowing from its headwaters northeast of Birmingham, AL until it reaches the Alabama River southwest of Selma, the Cahaba River is 194 miles long and drains an area of 1,870 square miles.
The 1,870 square mile Cahaba watershed drains urban and rural areas, farms and forests on its course from the southern Appalachian Mountains through the coastal plain to the Alabama River. About 200 square miles of the headwaters are the primary raw water source for the Birmingham Water Works Board system, the largest water provider in Alabama.
A great diversity of life depends on the Cahaba River, with Alabama’s longest remaining stretch of free-flowing river, the primary drinking water source for one-fifth of the state’s people in the Birmingham metro area, and a treasure of biological diversity of national and global importance.
The Cahaba River is one of the most biodiverse waterways on Earth. It has more species of fish than any other river of its size in North America.
International conservation organizations consider our southeastern rivers to be globally significant ecosystems and the Cahaba to be especially important to conserve for its rich biological diversity and scenic beauty. The Cahaba has more fish species per mile than any other river in North America and a similar richness of turtle, crayfish, snail, and mussel species. That rich biodiversity has merited these accolades:
The Cahaba is a major asset to the urban area and Alabama. Much of the Cahaba’s main channel is wild, beautiful, and very popular for canoeing, fishing, swimming, and environmental education. Canoe and boat launches are accessible from downtown Birmingham and many suburban and rural communities. The river is central to eco-tourism strategies for rural counties, including those in the Black Belt of Alabama.
Storm water impacts from suburban development in the upper watershed are the greatest challenge to the river system’s water supply, water quality, and biodiversity. Sediment runoff from construction is the immediate threat. In addition, the destabilizing force of increased storm runoff volume from additional paving and roofs is a swiftly growing problem. In recent years the damage has become much more apparent in the river and its tributaries: lower flows in dry weather, mud-covered and radically reshaped stream beds and collapsed stream banks, muddy and algae-choked water, and degraded conditions for recreation and wildlife.