A new report card gives the Mississippi River Watershed an overall "D+" grade based on its performance in six key areas — ecosystems, transportation, recreation, flood control, water supply and the economy.

The report card by America’s Watershed Initiative summarizes the challenges facing the Mississippi River Watershed, which includes 31 states and some 250 rivers. The coalition includes more than 400 businesses, government agencies, academic institutions and other organizations.

"The watershed continues to experience...