Our Mobile Bay Watershed

This map shows the extent of the Mobile Bay Watershed.

This map shows the extent of the Mobile Bay Watershed.

The Mobile Bay Watershed encompasses 65% of the land area for the state of Alabama, along with portions of Mississippi, Georgia, and Tennessee. Mobile Bay is the end-point for the Mobile, Tombigbee, Black Warrior, Alabama, Coosa, and Tallapoossa Rivers. The watershed is a vast network of more than 250 separate waterways, including rivers, bays, creeks, bayous, lakes, cutoffs, branches, and sloughs. 

A 40-mile-long braid of rivers and bayous spreads over cypress swamps, bottomland forests, marshes, and bogs to form the unrivaled Mobile Tensaw Delta. The expansive Delta is considered one of the most biologically diverse ecosystems in North America - “North America’s Amazon.” It opens into the northern end of Mobile Bay in an area called Five Rivers, which consists of the Mobile, Spanish, Tensaw, Apalachee, and Blakeley rivers. These rivers, carrying millions of gallons of water, conclude their long odyssey as they pour into Mobile Bay. The Bay is approximately 32 miles long and 23 miles across at its widest point. The average depth in Mobile Bay is only about 10 feet, which makes it one of the most shallow bays of its size.

Mobile Bay is Alabama’s central estuary, serving as a transitional zone where the rivers’ fresh water can mingle with tidally-influenced marine waters. An estuary is a partially enclosed body of water formed where freshwater from rivers and streams flows into the ocean, mixing with the salty water. Estuaries are environmentally and economically important because of their exceptional biological diversity and productivity.

  • The Mobile Bay Watershed covers two-thirds of Alabama -- Roughly 45,000 square miles.

  • More than 250 rivers, bays, bayous, creeks, inlets and sloughs flow into the watershed.

  • On average, 33.5 trillion gallons pass through annually, making it the fourth largest drainage basin in North America.

  • Major Habitat Types: Submerged aquatic vegetation (seagrass), reefs (artificial), barrier islands/sand bars, lagoon/shallow open water shell fish growing areas, beach/dune (bare & vegetated), sand/mud/salt flats, salt/brackish marsh, freshwater marsh (tidal & non-tidal), forested wetland, seasonal wetland, freshwater lakes/ponds, grass/open field, non-wetland forest, riparian/riverine (forested, tidal, & flood plain) abandoned, & agricultural.

Alabama is home to an immense diversity of plant and animal life, ranking fourth nationally in overall diversity. Alabama ranks number ONE for freshwater fish, mussels, turtles, snails, and crayfish species. Our Delta is home to more than 800 species of non-vertebrates, 337 species of fish (36 at risk), 126 amphibians & reptiles (30 at risk), 355 Birds (38 at risk), 49 mammals (7 at risk). (See Mobile Bay NEP for more information.)


Economic Impacts:

The health of our local economy depends on the health of the Mobile Bay Watershed. Recent data cites the following economic impacts:

  • dockside value of commercial landings at $80.5 million

  • value of dockside landings, processing and wholesale at $738 million

  • economic output of recreational saltwater fishing at $561.8 million

  • saltwater fishing jobs at 6,480

  • the Port is responsible for 134,608 direct and indirect jobs

  • the Port has a total economic value of $22.4 billion

  • Baldwin County's beaches account for nearly 40% of tourism spending in Alabama

  • In 2009, Mobile & Baldwin counties’ employment related to the waterfront or ocean economy sector amounted to 8,736 and contributed $1.57 billion to the GDP.


Mobile Baykeeper speaks for the Mobile Bay Watershed and our coastal communities.

We exist to advocate for the Mobile Bay Watershed and Coastal Alabama, working for clean water, clean air, and healthy communities. A healthy watershed ensures a growing and vibrant community, a high quality of life, and a resilient economy. Mobile Baykeeper exists to protect it.


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