Mississippi’s Aquatic Resources

Our state’s economy and quality of life depend on our delicate water resources.

major rivers in mississippi

Mississippi has 10 major river basins with 86,000 miles of streams. Connected end-to-end, Mississippi’s waterways would wrap around the earth 3 ½ times!

Most of our streams (63%) are intermittent, meaning they flow only during rainy periods.

The rest flow year-round, with a base flow – their normal water level – fed by ground water from aquifers.

The state is covered with hundreds of lakes, reservoirs, and ponds that provide wonderful recreation, as well as essential irrigation for crops and habitat for our abundant plants and aquatic life.

Mississippi has over 2,400 miles of man-made ditches and canals used for drainage and transportation, such as the164-mile Tennessee-Tombigbee Waterway. Completed in 1984, the Tennessee-Tombigbee Waterway is the largest earth excavation project ever completed, more than double the size of the Panama Canal!

Wetlands cover about 2.7 million acres throughout the state, providing habitat for wildlife and natural filters for cleaning stormwater runoff on its way downstream.

Most of our streams and rivers flow to some point along Mississippi’s 86-mile coastline. Many flow into estuaries – coastal bays that contain a a mix of fresh and salty water – such as St. Louis Bay, Back Bay of Biloxi, and Pascagoula Bay. These bays then continue south and enter the Mississippi Sound, and ultimately, past our barrier islands and into the Gulf of America. Other waters, like the Yazoo River, flow into the Mississippi River which discharges directly into the Gulf of Mexico south of New Orleans. In all, Mississippi’s estuarine waters cover over 750 square miles.

Barrier islands and coastal estuaries reduce the impacts of hurricane storm surges and provide the nursery habitat needed by both commercial and non-commercial fisheries.

Water Resources in Mississippi

The Mississippi River: The Mississippi River drains 40% of the continental U.S., some 1.2 million square miles, and is also the 2nd longest rivers in North America. The river supports a tremendous diversity of plants and wildlife and is a critical migratory route for birds. It is also one of the world’s most important commercial waterways, with 500 million tons of cargo transported annually.
Aquifers: Mississippi sits atop one of the most productive aquifers in the U.S.—the Sparta Aquifer, which supplies drinking water to over 90% of the state’s population.
Wetlands: Mississippi has over 4 million acres of wetlands, providing critical habitat for wildlife and serving as natural filters for water quality.
Reservoirs: Created by the U.S. Army Corps of Engineers, the state’s artificial lakes, or reservoirs, provide many important functions such as flood control, recreation, and public water supply. Six large reservoirs are present in the state – Barnett, Enid, Grenada, Sardis, Arkabutla, Okatibbee.
Estuaries: The Gulf Coast features rich estuarine systems like the Pascagoula River Estuary—one of the last free-flowing rivers in the contiguous U.S.—and Biloxi Bay. Estuaries are shallow areas where freshwater from rivers and saltwater from the ocean mix to form brackish (semi-salty) ecosystems. Estuaries serve as critical habitats for many aquatic animals, help protect coastlines from storm surge flooding, and function as water filters that mitigate coastal pollution.

Aquatic Life in Mississippi

Home to the Rare Gulf Sturgeon: The Gulf sturgeon, a prehistoric, endangered fish that can grow up to 9 feet long, migrates up Mississippi rivers from the Gulf of Mexico to spawn.
High Freshwater Fish Diversity: Over 200 species of freshwater fish call Mississippi home, including unique species like the Yazoo Darter, found only in the upper tributaries of the Yazoo River basin.
Crayfish Capital: Mississippi is home to more than 60 species of crayfish, many of which are endemic, meaning they exist nowhere else in the world.
Unique Mussel Species: The state’s rivers support dozens of freshwater mussel species, some of which are federally endangered, like the inflated heelsplitter.
Pascagoula River – a Biodiversity Hotspot: Often called “America’s Amazon,” the Pascagoula River system supports one of the most biologically rich ecosystems in North America, with numerous rare fish, amphibians, and reptiles.