The nation's waterways will be made more vulnerable to terrorist attacks if a White House plan shifting dollars away from securing that resource is pushed through, one lawmaker said Wednesday.

House Appropriations Committee members pelted top officials of the U.S. Army Corps of Engineers with questions on this issue as the panel began hearings Wednesday on the agency's budget for next year.

Rep. Jo Ann Emerson, R-Mo., took issue with a proposal from President Bush to take dollars away from upgrading locks and dams on the nation's rivers to spend more on regular maintenance of the nation's waters.

The Bush plan would siphon money from the Inland Waterway Trust Fund to pay for routine maintenance and operations. The fund, which collects taxes on diesel fuel from the barge industry, is supposed to be used only for major construction to upgrade ports, locks and dams.

The agency took a hard look at the security of the nation's waterways after the Sept. 11 terrorist attacks as vulnerabilities in the country's critical infrastructures were put in the spotlight.

The review found that safety upgrades were needed at 85 locks, dams, hydropower plants and other facilities, out of 306 that were reviewed.

Emerson said she couldn't understand how the Corps could finish security upgrades when it is also facing a $1 billion backlog in regular maintenance and operations.

"If we divert that money to operations and maintenance, aren't we then unable to complete ongoing projects?" she asked. "How, then, are we going to be able to make sure that not only are projects completed, but also, how are we going to protect these waterways from terrorist activity if the money's being diverted elsewhere?"

Ohio GOP Rep. David L. Hobson, the chairman of the energy and water spending subcommittee, said the trust fund will run out of money in three years if the Corps taps it for day-to-day needs.

The Corps' overall budget this year is $4.6 billion. The Congressional Budget Office wants $4.194 billion for next year.

But despite all the political criticism, House members didn't ask for answers right away and congratulated Corps officials for handling themselves well despite all the criticism.

"You're being very statesmanlike in light of what happened to the last person in your job," Rep. Chet Edwards, D-Texas, told Les Brownlee, acting assistant Army secretary for civil works.

He was referring to Mike Parker, whom President Bush fired last year after Parker criticized the administration's planned budget cuts.

"Certainly, to use those [funds] for inland waterways or harbors where it's accumulated a balance would appear to be legal," Brownlee said.

He said the agency proposes to use $104 million of its regular operations funds for security improvements.

Emerson and her appropriations allies used Midwestern farmers as an example of how the waterway system is in need of an overhaul.

They argued that farmers are saddled with a depression-era navigation system that was never designed to handle today's massive shipments of grain and other commodities.

But critics of the Army Corps of Engineers want to use the trust fund for other purposes and say the big projects the Corps wants to spend money on simply aren't needed.

"Many of the Corps' navigation projects are based on questionable economic and environmental analysis," said Scott Faber, a spokesman for the Environmental Defense group. "The net effect is that we've needlessly destroyed some rivers based on grossly optimistic predictions of future barge traffic."

Faber noted that a National Academy of Sciences review even concluded that the agency was biased in favor of huge construction projects.

Last year, Sen. Tim Johnson, D-S.D., proposed to use the industry-funded trust money for routine maintenance and operations on less-used waterways. His measure would have saved taxpayer dollars for the operations of rivers with heavy traffic, such as the Mississippi, Illinois and Ohio rivers and the Intercoastal Waterway.

His bill never saw the light of day, however, as it died in committee.

The Associated Press contributed to this report.