|
The Black Warrior and Tombigbee Rivers merge with the Alabama
River near McIntosh, Alabama to
form the Mobile River. It in turn empties into Mobile Bay on the Gulf of Mexico.
The rugged terrain in the upper reaches of the Black Warrior is characterized by
high ridges and deep river gorges. The upper Tombigbee basin is hilly but below
the fall line it is low and gently rolling like the coastal region of the Black
Warrior.
The Black Warrior basin has abundant natural resources and is one of the most
highly industrialized areas in the Southeast. The Tombigbee basin is primarily
agricultural.
The two rivers have played a vital part in development of
their basins. First explorers, then traders and settlers used the rivers as
water highways. The settlement of the town of Mobile was successful largely
because of its ideal location to serve as a port of the inland river system.
In the nineteenth century, cultivation of cotton and
invention of the paddlewheel steamboat stimulated trade on the rivers. But
hazards such as sandbars, fallen trees and shoals impeded navigation. In 1875,
the first plans to improve the rivers for navigation were approved.
Between 1895 and 1915, a system of 17 locks and dams was
constructed between Mobile and Birmingham. In those days, waterway construction
was a slow and laborious task. Dams were built by hand of stone and mortar.
Locks were walled with stone-filled timber cribs, and hauling was done by
mule-power.
The original locks and dams were built to provide a six-foot-deep channel,
adequate for the steam-powered tow boats and packets of the era. The Corps
undertook a program to modernize the system in 1937. The 17 low-lift locks were
replaced by six high-lift locks, capable of expediting present-day towboats and
barges. The locks vary in maximum lift from 22 to 69 feet. The nine-foot
navigation channel is maintained to a width of 200 feet. Tows of up to eight
standard barges can be accommodated at all locks.
The waterway is now approximately 457 miles long. All
of the original locks and dams have been replaced except for John Hollis
Bankhead Dam on the Black Warrior near Birmingham. The structures at Bankhead
were the last of the original locks and dams built on the system. Bankhead dam
has been modernized and a new lock has been constructed to make it comparable in
efficiency to the other locks and dams in the system.
|