The Environmental Protection Agency has barred the Corps of Engineers from building a flood-control project in the Mississippi Delta on grounds that it would harm wetlands and wildlife. EPA’s final decision, announced on Sept. 2, blocks the Yazoo Backwater Project, which includes a 14,000-cu-ft-per-second pumping station to drain rainwater during Mississippi floods. The project was first authorized in 1941 and has an estimated construction cost of $220 million and operating costs of $2 million a year. EPA says it will work with federal and state agencies to find an alternative plan.

Environmental groups, which fought the project, hailed the EPA action. Rebecca Wodder, president of American Rivers, says it was the first block by EPA of a water project since 1990.