EVERYBODY IN Congress would agree that the budget deficit is a problem -- it's just that there's always a reasonable case for a little extra spending. Health, education, homeland security, defense: It's hard to say no, with the result that total spending heads upward. Occasionally, however, one comes across a large spending proposal that is clearly and unambiguously awful. The $1.7 billion lock expansion on the upper Mississippi River is an example.

The Mississippi waterway connects the grain and corn of the Midwest to the export hub of New Orleans. The barges that ply this route have to pass through a series of locks, where congestion sometimes causes delays and extra costs for exporters. But the $1.7 billion price tag for reducing this congestion by expanding the locks is impossible to justify -- despite repeated attempts to do so.

The Army Corps of Engineers, which would do the construction, studied the project 11 years ago and found it to be economically unjustified, particularly because cheap expedients such as congestion pricing would be nearly as effective. To placate the Midwestern congressional delegation, the Corps buried that finding and produced new calculations that appeared to justify the expense, but the National Academy of Sciences reviewed its methodology and pronounced it bogus. The Corps produced a third study, which also sought to please Midwesterners by justifying longer locks; again the National Academy of Sciences shot holes in its calculations. After three attempts, in other words, the Army Corps of Engineers has failed to come up with calculations that justify the project.

This may be why neither the House nor the Senate has approved it. But Midwestern lawmakers from both parties, led by Sen. Christopher S. "Kit" Bond (R-Mo.), remain determined to make the nation's taxpayers assist farm exporters in their states, and so authorizing language for the upper Mississippi project may be slipped into one of the spending bills that will soon move through Congress. Authorizing this boondoggle at a time of huge budget deficits and during an expensive war would be the height of irresponsibility. Leaders in both chambers must prevent it.