Overview
- Upper basin in carbonate valleys; Lower basin in the coastal plain
- Longest free-flowing river in Alabama
- Extraordinary biodiversity of fishes and mollusks
- Impacted by Birmingham
- One-fourth of Alabama’s population drinks, cooks with, and bathes in water from the Cahaba River every day
Cahaba River Facts
Major Physical Features
- Basin area (km2): 4,730
- Mean discharge (m3/s) (1938-2000): 80
- Mean precipitation (cm/yr): 138
- Physiographic provinces: Ridge and Valley, Appalachian Plateau, Coastal Plain
Major Biological Features
- Terrestrial biome: Eastern Deciduous Forest
- Number of fish species: 135
- Number of endangered species: 3
Major Fishes
Paddlefish, Alabama sturgeon, spotted and longnose gars, mooneye, American eel, Alabama shad, skipjack herring, gizzard and threadfin shads, Alabama shiner, blacktail shiner, tricolor shiner, pretty shiner,speckled chub, silver chub, emerald shiner, cahaba shiner, silverside shiner, fluvial shiner, skygazer shiner, mimic shiner, bluntnose and bullhead minnows, riffle minnow, quillback, highfin carpsucker, southeastern blue sucker, smallmouth buffalo, Alabama hog sucker, spotted sucker, river, golden and blacktail redhorses, blue, channel and flathead catfishes, frecklebelly madtom, redfin and chain pickerels, white bass,shadow bass, warmouth, green, bluegill, longear, redear, and redspotted sunfishes, spotted and largemouth basses, white and black crappie, naked sand darter, southern sand darter, crystal darter, rock darter, goldline darter, coal darter, blackbanded darter, saddleback darter, Mobile logperch, and freshwater drum
Major Invertebrates
- Mussels – southern fatmucket, Alabama orb, elephant ear, bleufer, three-horned wartyback, southern rainbow, Asiatic clam
- Gastropods – Elimia cahabensis, E. clara, E. pupoidea, E. showalteri, Leptoxis sp., Somatogyrus, Physella, Ferissia, Micromenetus, Fossaria
- Insects – Cheumatopsyche, Hydroptila, and Cyrnellus, Acroneuria, Stenacron, Stenonema, Tricorythodes, Eurylophella, Ancyronyx, and Chironomidae (Ablabesmyia, Polypedilum, Tribelos)
Non-Native Species
Fourteen species of freshwater fishes have been introduced, three species (goldfish and grass and common carps) are exotic species; Asiatic clam
Major Riparian Plants
Bald cypress, eastern cottonwood, swamp cottonwood, mockernut hickory, river birch, American hornbeam, American beech, southern red oak, water oak, live oak, American elm, yellow-poplar, sweetgum, American sycamore, American holly, red maple, blackgum, water tupelo, swamp tupelo, carolina ash
Special Features
The Cahaba River is the longest free-flowing river in the southeastern Gulf Coast Region. It contains the largest number of fish species for its size in North America.