The Army Corps, the federal agency responsible for building dams and designating flood plans, has long been criticized by environmental groups for wasteful spending and rigging data to justify projects that create jobs. It operates 630 dams for flood control and navigation across the United States.

Under pressure from Congress, the Corps has promised reforms to trim its huge $52 billion backlog of projects. Several bills have been introduced to create an independent task force to oversee and approve large projects for the Corps before they can begin.

Among the Army Corps' most controversial projects is a $60 million study that endorsed upgrading the aging 70-year-old lock and dam system in the Mississippi River. Several independent studies, including one from the U.S. Office of Special Counsel, said there was an atmosphere within the agency that "led to manipulation" of some data.

"Can the process be made better? You bet," Lt. Gen. Robert Flowers, the chief engineer of the Corps, told reporters. "But I think we need some national debate and a partnership like this one ... is an eye or window to the future."

The Army Corps and the green group said the alliance would try to work out potential conflicts that often arise over environmental issues, slowing river restoration projects.

Last month, Sens. Robert Smith, a New Hampshire Republican, and Russ Feingold, a Wisconsin Democrat, threatened to stall funding for a slew of projects unless there are reforms.

"This (agreement) is significant, and yet at the same time relatively modest," said Steven McCormick, president of The Nature Conservancy.

"We want to be focused, we want to be strategic and we want to reinforce the notion that this is an effort at gaining additional understanding of how river systems work and how the two agencies can work in "harmony," he said.

The Conservancy and the Army Corps already have an existing collaboration to improve the habitat of the Green River in Kentucky, which will serve as the model for Tuesday's agreement.

The partnership, signed in December 2000, resulted in delaying the release of the fall reservoirs until after the spawning period for certain fish and mussel species.

The delay, which also helped extend the recreation season and improve water quality, still allows the dam to prevent flooding for farmers and residents downstream.