Back in September, as evidence mounted that the U.S. Army Corps of Engineers fudged data used to justify a $1.1 billion navigation project on the Mississippi and Illinois rivers, a small bipartisan group of senators called for sweeping reform of the increasingly large, powerful and unaccountable agency. The majority of senators, at the urging of leadership, decided that a study of reform would be sufficient.

Results of an investigation released last week by the Army inspector general prove that to have been the wrong decision. The investigation did not just produce a 168-page report finding the Corps had manipulated its cost-benefit analysis of the massive Midwest lock project to favor construction, it produced an alarming indictment of the Corp’s overall practices in evaluating huge public projects and of the pressure business interests and members of Congress apply to get the desired, even if erroneous, results.

The evidence that led to the conclusion that the river study was manipulated to favor construction is irrefutable.

A paper trail of internal memos and e-mails from top Corps officers to the subordinates preparing the analysis made it blatantly clear that the numbers must be made to add up; if they didn’t, numbers should just be made up.

Even worse, the investigation uncovered widespread institutional bias in favor of huge projects. A policy of expanding the Corp’s mission has infected the entire agency with pro-construction fever and pressured local divisions to come up with projects and, that done, to find ways to increase their size and expense. The report makes the cause of this ”mission creep” clear – the Corps is under tremendous pressure from members of Congress to bring projects home and members of Congress are themselves under tremendous pressure from business interests back home. The Mississippi-Illinois case is telling: Impartial analysis found no indication the enlarged locks would increase river barge traffic and economic activity in any substantial way; they would, however, result in relatively small savings in time and money for the barge operators, at an enormous cost to taxpayers.

But the worst part of the report is not a conclusive finding but a strong indication that the Corps punished employees who refused to fudge. The Mississippi-Illinois case was brought to light by Corps economist Donald Sweeney, who was removed from the project after he determined that the cost of the locks would far outweigh their benefits. Although the inspector general substantiated the allegations of misconduct lodged by Mr. Sweeney, there is no concrete proof that the courageous whistle-blower was fired for telling the truth. There is, however, the unmistakable stench of retribution.

No such employment problems for the three officers the inspector general identified as the primary perpetrators of the lock-project scam – a general and a colonel are enjoying comfortable retirements, another general has been re-assigned out of harm’s way.

The Pentagon has done a commendable job of investigating itself here, but the challenge now is whether it can reform itself. Secretary of Defense William Cohen has directed Secretary of the Army Louis Caldera to make the necessary changes that will restore public confidence in the Corps. The bigger question, though, is whether Congress, which created the conditions for this scandal, will do the same.