The aroma of politics wafts strong in the “final decision” by the Environmental Protection Agency’s senior water management official to use a subsection of a subsection of the 1979 Clean Water Act to veto the final, essential step in the Yazoo Backwater Project, created by Congress in 1941.

Even pleas from Republican Gov. Haley Barbour and Mississippi’s two Republicans in the U.S. Senate, Thad Cochran and Roger Wicker, were not enough to stave off the 74-page Final Determination Report signed by Benjamin H. Grumbles, the EPA’s assistant administrator for water.

Pumps to remove some of the water that becomes impounded inside a 4,093-square-mile area of the Mississippi Delta while levees hold back floodwaters from the Mississippi and Yazoo rivers would “significantly degrade” ecological functions for up to 67,000 acres of wetlands, Grumbles believes, so the agency invoked the most sweeping “veto” it has ever issued.

Please pause a moment to consider the ramifications of this decision if, as appears likely, it stands.

After the 1927 Flood, Congress tasked the Army Corps of Engineers with consolidating levee design and construction as well as performing work to maintain river navigation while limiting flooding as much as feasible.

Toward that end, the Yazoo Backwater Project was a component. Millions upon millions of dollars were spent on measurements, studies, designs and actually moving dirt to protect the Delta from overland flooding.

All the while, it was contemplated that water accumulating on the flat, fertile field would need to be removed by pumps.

But now landowners are pretty much back where they were. Yes, they are protected from direct, overland flooding by the levees and control structures. But their land — along with timber and wildlife areas — can be rendered just as useless by rainwater trapped, as it was in the Flood of 2008, with nowhere to go.

And not only did local conditions prove the need for pumps this year, a parallel situation occurred in New Orleans last week. There, after Katrina, the Corps finally won permission to place gates and pumps on the city’s key outflow canals. The gates were closed as Gustav approached and they kept the storm surge out. But while the gates were closed, pumps were employed to move rainwater falling in the city out over the levees and into Lake Pontchartain.

It’s doubtless that water control projects have environmental consequences. The EPA is right about that. For too long, the Corps and the nation disregarded those consequences. Today, however, there’s a far better balance and it was clearly proved in the latest pump plan drafted by the Vicksburg District of the Corps.

But President Bush has a record of finding civil waterworks efforts “unworthy.” That meant the administrative agency’s veto came as no real surprise.

Too bad. It means hundreds of millions of tax dollars have been spent over the past 67 years — yet large portions of the Delta will be as vulnerable to flooding as they were before the first penny was allocated. Maybe the next administration will be more sensible.