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THE GREAT RIVERS PARTNERSHIP brings together diverse stakeholders and best science to work toward sustainable management and development of the world’s most critical river systems.

 Mississippi River Basin

Misssippi Basin - � Robert J. Hurt

The Mississippi River has the third largest drainage basin in the world, exceeded in size only by the watersheds of the Amazon and Congo Rivers. It drains 41 percent of the 48 contiguous states of the United States.

Likewise, the basin covers more than 1,245M square miles (or 3,225M square kilometers) and includes all or parts of 31 states and two Canadian provinces. Waters from as far east as New York and as far west as Montana contribute to flows in the lower river, and create an overall basin that resembles a funnel its spout emptying into the Gulf of Mexico.

Economic Viability

More than half the goods and services consumed by citizens of the United States are produced with water that flows through the Mississippi River and its major tributaries the Ohio, Missouri, Arkansas and Red rivers. Agricultural products from the basin are worth $54 billion annually and represent 92 percent of the nation's farm exports.

The Mississippi also serves as a vital conduit for goods, is home to the largest port in the U.S., and gives life to the Gulf of Mexico's vibrant seafood industry. Its basin supports commercial fishing and outdoor recreation as well, generating billions of dollars each year to support local and regional economies.


More than 400 native species of freshwater fish call the basin home. The Mississippi also acts as a vital migration corridor for 60 percent of North America's bird species and provides critical habitat for freshwater mussels, otters and other creatures including the rare Louisiana black bear.

Conservation Challenges

The Mississippi River Basin has been highly altered over the last 200 years as a result of conversion of land from grassland and forest to agricultural production and urban areas; protection of people and property from variable and sometimes devastating floods; and construction of a commercial navigation system to transport agricultural and other bulk commodities to national and international markets.

Today, the river has altered hydrology, altered sediment and nutrient cycling regimes, and altered flows and longitudinal connectivity, and altered lateral connectivity within the river floodplain. Over time, many of these alterations have led to environmental degradation, which has been the inspiration for management actions to mitigate the impacts.

Management Challenges

The Nature Conservancy has been engaged throughout the basin for decades, and the first phase of the GRP took TNC to new levels of involvement with agencies, organizations, policymakers and diverse stakeholders focused on the river, its floodplain and several of the adjacent watersheds.

The major management challenges to safeguarding the ecological integrity of the Mississippi River Basin and the areas where the GRP will continue to focus efforts include:
  • Governance - Uniting diverse stakeholders, sectors and geographies behind a shared vision and building recognition for the basin; using sound science and best practices to inform policy alternatives and measuring progress toward a healthier watershed that is economically, socially and ecologically sustainable.

  • Sustainable Agriculture - Increasing production with environmentally sustainable practices by working with producers; informing, developing and influencing policy and sustainable agricultural practices through demonstration projects that reduce sediment and nutrient agricultural runoff; working with agricultural partners to create change from production to delivery through the collaboration of Field to Market.

  • Resilient Floodplains  - Demonstrating and sharing the value of floodplains at protected sites and in working land settings that provide ecological benefits and income for private landowners; work with federal agency partners to promote sustainable programs; influence policy to create more opportunities to mix green and grey infrastructure through key legislation.

America's Watershed Initiative

In an effort to create a collective vision for the river and find solutions that address the full watershed, America's Watershed Initiative unifies stakeholders across 31 states.