WASHINGTON — The Corps of Engineers on Tuesday proposed a new southeastern water-sharing plan that would allow lower river flows into Florida's Apalachicola Bay during extreme drought — a move that the Corps acknowledged is likely to harm threatened species there.

The new plan comes after settlement negotiations among the governors of Florida, Georgia and Alabama broke down in February, prompting Interior Secretary Dirk Kempthorne to say that the federal government would impose its own solution.

The plan, released to lawmakers Tuesday morning, would allow upstream lakes to retain more water in times of drought by allowing waivers of the current minimum flow requirement of 5,000 cubic feet per second at the Jim Woodruff Dam near the Florida line. The plan also allows for more storage retention in upstream lakes during rainy times.

The plan covers the Apalachicola-Chattahoochee-Flint river basin that runs south into Florida along the Georgia-Alabama line.

In an accompanying letter to the U.S. Fish and Wildlife Service, the Corps wrote that modeling has shown that the changes "are likely to adversely affect" threatened mussels and sturgeon. The corps asked Fish and Wildlife for a new biological opinion on the changes but said the new plan would be implemented until further talks are completed.

"It is understood that our consultation discussions over the coming weeks could identify additional modifications to the current IOP that could provide for additional minimization of harm to the species," the letter says.

The three states have been feuding for nearly two decades over water rights in the Apalachicola-Chattahoochee-Flint and the Alabama-Coosa-Tallapoosa river basins.

Georgia is fighting to hold back more water in federal reservoirs around Atlanta to serve its growing population.

Florida and Alabama argue that Georgia hasn't adequately planned for growth. The extra withdrawals, they argue, would damage the environment and dry up river flows into their states that support smaller municipalities, power plants, commercial fisheries and industrial users like paper mills.

With a record drought creating a critical water shortage last fall, President Bush dispatched Kempthorne to try to settle the dispute. But the talks ultimately failed and the states are now focusing on litigation to settle the matter.