The Black Warrior River contains the largest drainage area entirely within Alabama’s borders. The entire watershed drains approximately 6,276 square miles of land.
The Rivers principal forks, the Sipsey, Mulberry, and Locust, begin in North Alabama and converge to form the Black Warrior to the west of Birmingham at the Jefferson County, Walker County line.
After the river forms and for the next several miles the Black Warrior once tumbled over some of the largest shoals in the state until it reached the site of present day Tuscaloosa. It is here that the river flows across the Fall Line, a geologic barrier separating the high and hilly Cumberland Plateau from the flat and loping East Gulf Coastal Plain. At one time the coast of an ancient sea cut across what is now the interior of Alabama in a great arch from Tuscaloosa to Montgomery. The land south of this line held the ocean, and to the north a rocky coast.
The Fall Line is the single most significant land feature for many rivers in Alabama including the Black Warrior. This topographic feature serves as a definitive barrier to fish species. 19 species are limited to the Warrior below the fall line and 5 are limited to the Warrior above the fall line (Mettee)
The Upper Black Warrior Watershed above the fall line flows through sandstones, shales, and limestones of the Cumberland Plateau and streambeds are characterized by a moderate to steep gradient and by rocky shoals and riffles. Elevations range from 1,100 feet on the northern slopes to 600 feet near Tuscaloosa and the Fall Line Hills (Metee).
Below the Fall Line the Lower Black Warrior Watershed flows through the sediments of the upper Coastal Plain and is characterized by low, generally rolling hills with elevations between 150 and 300 feet. The stream gradients in this section average one foot per mile and stream bottoms consist of sand, gravel and mud. About 75% of the basin is above the Fall Line and 25% falls below in the Lower Black Warrior system. (Williams)
As the river continues to grow in strength, it flows through a thin belt of Black Prairie (or Black Belt) where Alabama’s finest soils are plowed. The river ends by delivering its flow into the east bank of the Tombigbee River just north of Demopolis. This confluence also marks the pinnacle between Greene, Sumter and Marengo counties.
Upland habitats consist of spruce pines that occur along the edges of bluffs while beech, maple, poplar and gum trees occur on slopes along streams. (Mettee)
Perhaps one of the characteristics that has best served to define the past, present and future of the Black Warrior River Basin is its vast deposits of coal. The Black Warrior Basin is the southernmost largest coal producing area in North America. (Metee) The Black Warrior Coal Field covers 4,000 square miles and is the largest coal field in the state.
Average rainfall within the watershed is 52 inches annually. (Williams)
The appearance of the main stem is vastly different today due to the rivers manipulation for navigation. Before the construction of locks and dams, the Black Warrior tumbled over some of the largest and most beautiful shoals in Alabama. Squaw shoals, now flooded by John Hollis Bankhead Lake was perhaps the world’s largest stand of shoal lilies and also harbored many species of fish and thirty species of mussels. (Lydeard) Squaw Shoals began just above Yellow Creek and ended just before Blue Creek on the Warrior’s west bank.
While the Black Warrior river mainstem occupies only 5 counties (Jefferson, Walker, Tuscaloosa, Hale and Greene) before draining into the Tombigbee River near Demopolis, the streams comprising its watershed flow through an additional 10 counties (Marshall, Etowah, Blount, Morgan, Cullman, Lawrence, Winston, Fayette, Bibb, and Perry).
Red Mountain serves as the drainage divide between the Warrior and Cahaba River systems.