Concerned that the Mississippi River doesn’t reach levels that prohibit commercial navigation, agricultural groups are urging President Obama to issue a presidential declaration of emergency.

A joint letter signed by some 20 national organizations – including the American Farm Bureau Federation – said there could be an economic catastrophe in America’s heartland as soon as mid-December if the administration does not take emergency action.

Because of severe drought in 2012, waterborne commerce on the middle Mississippi River is in danger, especially now that the U.S. Army Corps of Engineers has begun to implement plans to reduce the release of water to the river from dams on the upper Missouri River.

“The Mississippi River is a critical national transportation artery, on which hundreds of millions of tons of essential commodities are shipped...,” stated the letter. “Substantial curtailment of navigation will effectively sever the country’s inland waterway superhighway, imperil the shipment of critical cargo for domestic consumption and for export, threaten manufacturing industries and power generation and risk thousands of related jobs in the Midwest.”

The groups’ letter follows a similar warning by Louisiana Department of Agriculture and Forestry Commissioner Mike Strain. Strain’s Nov. 27 missive to the U.S. Army Corps of Engineers, the Louisiana congressional delegation and federal leaders urged that the Corps not reduce water flow from a reservoir into the Missouri River which flows into the Mississippi River near St. Louis, Mo. This action is normally taken by the Corps to prepare for ice buildup and flooding during the winter months.

“Low river levels already exist because of the widespread drought. Reducing water flow would only exacerbate the situation. Barges carrying grain and other products will not be able to navigate the Mississippi if water levels drop even lower,” said Strain. “In December and January alone, $7 billion in product is expected to travel up and down this waterway. The ports in south Louisiana are dependent upon this cargo.”

“It is critical that (President Obama) take immediate action to ensure grain and other products can be moved to maintain this economic lifeline. There is a growing demand for our products, and if farmers are unable to ship their commodities, it will ultimately lead to higher prices for the consumer. That’s the last thing families need right now,” added Strain.

Aside from issuing an emergency declaration, the concerned groups requested that President Obama direct the Corps to immediately remove the rock pinnacles along the river and release enough water from the Missouri River reservoirs to preserve a nine-foot navigation channel on the Mississippi River.

Attached to the joint letter were letters from the governors of Missouri, Illinois and Iowa, 15 U.S. Senators, and 62 U.S. House members urging prompt federal action on Mississippi River navigation.