The waters were rising again. The sandbaggers were sandbagging again. The politicians were declaring disaster areas again. And the media were recycling cliche{acute}s about "hardy" Midwesterners battling "swollen" rivers in their "flood-ravaged" communities again. Yes, there was a 100-year flood event on the Mississippi River this spring.


This was the Mississippi's fourth "100-year flood" in the past eight years. In other words, the extra-high water levels that are supposed to come along about once a century have been drowning the region about once a House election cycle. The news media usually presents this as an odd coincidence, punctuating their stories with some hardy Midwesterner noting wearily that 100 years sure ain't what it used to be. But it's a real trend. Floods killed 957 people and caused $45 billion in damage from 1989 and 1998. They're getting worse.

And while there have been more intense rainstorms lately, these floods are not really natural disasters. They are natural events, but they are mostly man-made disasters. The federal government finally learned that lesson after the $12 billion Mississippi flood of 1993. It is not yet clear whether the lesson will stay learned in the Bush administration.

Here's how people created these disasters: First they settled and farmed in floodprone areas. Then they drained wetlands and farmlands that used to sponge up water during floods. Then they built levees and flood walls that imprisoned rivers into tight channels, walling them off from their natural flood plains. And all those artificial barriers -- as well as a generous federal flood insurance program -- have inspired a false sense of security that encourages even more Americans to build in those flood plains. Thus the cycle continues.

The result of all this human activity, a slew of studies suggest, is bigger and more destructive floods. The Army Corps of Engineers spent more than $100 billion trying to tame the Mississippi and its tributaries in the last century, but the nation's inflation-adjusted annual flood damages tripled since 1950. At Davenport, Iowa, the Mississippi exceeded flood levels five times in the first half of the 20th century, and 24 times in the second half. High water has become so routine that last week, a Minnesota official acknowledged that even a 100-year event is now considered "a nice medium-sized flood."

But an amazing thing happened after the Mississippi flood of 1993. (That was actually a 500-year event, although we probably won't have to wait 500 years for the next one.) A bipartisan consensus began to emerge that it makes more sense to buy out damaged homes in flood-prone areas than to pay people over and over to rebuild their damaged homes in flood-prone areas. Meanwhile, top federal officials began questioning the Army Corps' reliance on "structural" flood suppression projects designed to control America's rivers, pushing instead for "non-structural" approaches designed to move people away from rivers. They began to create a demilitarized zone in the 150-year war with the Mississippi.

Gen. Andrew Atkinson Humphreys lost more than 3,000 men in his division during the catastrophic Union charge up the hill at Fredericksburg in 1862, and he described the experience as "sublime." As he gushed to a friend, "I felt more like a god than a man." This was the man -- and the hubris -- that shaped the modern Mississippi.

Humphreys, who took over the Army Corps shortly after the Civil War, was the engineer who devised the "levees-only policy" for controlling the river. It was a little bit like moving in the sides of a bathtub. Levees lock the river into a narrower channel -- so the water has nowhere to go but up. As the historian John Barry chronicled in his 1997 book "Rising Tide," that folly became clear when the rampaging river overtopped some of its levees and ripped through others in the great flood of 1927, leaving a million people homeless and 16 million acres underwater.

After the flood, the Army Corps did design a few outlets to give the river and its tributaries some room to ramble during floods. For example, the Corps prepared a 180-square-mile emergency "floodway" in southeast Missouri. The plan called for the Mississippi to enter the floodway at Birds Point, where the Corps would dynamite a hole in the levee during high water, and return to its channel 60 miles away in New Madrid, where the Corps left a 1,500-foot gap in the levee. In 1937, the plan was executed for the first and only time, providing a desperately needed release valve.

But the main goal of the Corps was always to control the river, not to accommodate it. I spent most of last year examining the Corps, and I should point out that it's always been stocked with talented engineers. They built the Washington Monument, surveyed much of the West and completed the Panama Canal. And let's be clear: Their levees and flood walls have helped protect millions of homes and businesses. That said, the upshot of my reporting was that the military leaders of the Corps have tended to see fancy engineering as the answer to nearly everything, and Congress has tended to pass pork-barrel projects that have allowed the Corps to indulge its penchant for moving dirt and pouring concrete. The Corps also likes to keep busy, and its perennial war against rivers has created a perpetual work machine.

Levees and flood walls, after all, create an arms race. When the Corps builds, raises or strengthens a levee on one side of the river, it increases the pressure on the other side, and on downstream communities. So those communities demand taller and stronger Corps-built barriers as well. And as the nasty game show host can tell you, somebody's got to be the weakest link. This became painfully obvious in 1993, when an incredible 1,083 levees failed, swamping the buildings that had sprouted behind them. "If you're the poor sucker without the congressional clout to get the higher levees, you get all the water that year," says William Hartwig, Midwest regional director for the U.S. Fish and Wildlife Service. "Then the government spends $100 million, and the next time someone else gets the water."

Oh, one more point about levees: The 1993 damage could have been much worse if the doomed 1,083 hadn't failed. The water that rushed through crevasses and over sandbags to drown obscure communities such as Chesterfield and St. Genevieve would have stayed in the river instead, and might well have overtopped the floodwall in a somewhat larger community.

It's called St. Louis.

So that's one reason the bathtub keeps overflowing: The sides of the tub have moved closer together. But there's another problem: There's more water pouring into the tub.

The Mississippi River basin is the third-largest in the world, covering all or part of 31 states, draining two of every five drops of rain that fall on the continental United States. Before Americans settled the area, those raindrops used to take their time getting to the river. Many pooled in swamps, bogs and "prairie potholes." Others lingered in the soil.

But not anymore. Over half of the basin's wetlands have disappeared, including more than 80 percent in Iowa, Missouri and Illinois. Some were paved for roads and development. Most were drained for farms. The rainwater they used to absorb now zips straight into rivers. One study estimated that all the wetlands that have vanished from the Midwest would have held twice the volume of the 1993 flood at St. Louis. (Who's responsible for protecting those environmentally precious wetlands? The Army Corps of Engineers.) And farmers are also doing an unbelievably efficient job of draining relatively dry lands. From 1994 to 1999, for example, Minnesota farmers installed 125,000 miles of underground drainpipes -- enough to circle the earth five times -- sending more water into rivers at a faster pace. As hydrologist Donald Hey of the Wetlands Initiative points out: "The water's got to go somewhere."

In 1993, the water went almost everywhere. That's when things began to change.

After the flood, a White House commission led by a former Army Corps general concluded that the agency's addiction to "structural" flood control was promoting too much development in flood-prone areas. And President Clinton's Federal Emergency Management Agency (FEMA) director, James Lee Witt, was already committed to "nonstructural" approaches. His agency spent about $1 billion over the past eight years to buy out 27,000 flood-prone structures, about half in the Midwest. It moved the entire town of Valmeyer, Ill., to higher ground. Witt became the hero of the Clinton Cabinet, feted by politicians of both parties, praised by then-Gov. Bush and Vice President Gore during the presidential debates.

It may be too early to judge the efforts that FEMA bureaucrats call "hazard mitigation," but there are hopeful signs. In 1993, after St. Charles County, Mo., suffered $26 million in damages, the county moved nearly 1,400 structures out of the flood plain. The next flood soaked almost as much of the county -- and total damages were less than $300,000. Meanwhile, the federal government has paid farmers to convert about 600,000 acres of farmland back to wetlands; America is still losing wetlands, but not nearly as fast as it once was.

Even the Army Corps has changed its rhetoric. "It can't just be structural flood control, end of story," says Charles Hess, the agency's chief of operations. Last month, a Corps spokesman praised Davenport for moving homes out of its flood plain, even while the city was being criticized for refusing to accept a floodwall. "Our goal is not to build floodwalls up and down the river," the spokesman said. "Our goal is to protect property and lives."

The criticism of Davenport came from a high-placed source: Witt's successor, Joe Allbaugh, a longtime political adviser to Bush. Environmentalists who hate structural flood control were furious, but Allbaugh's main point was that the government should not bail out the same flood-prone people again and again, a point environmental activists have made for years. A National Wildlife Federation study found that 40 percent of all flood insurance payments go to repeat victims, even though they represent only 2 percent of policyholders. One house valued at $114,000 received payments worth $806,000 -- for 16 floods in 18 years.

That house, however, was located in Texas, which along with Louisiana has the most repeat flood victims in the nation. And the Bush administration's budget plan has prompted harsh criticism from state disaster officials and environmentalists for eliminating flood prevention initiatives, including a $162 million program that pays farmers to restore wetlands and a $25 million program that helps communities buy flood-prone properties. The budget did not fund any new projects for the Corps -- it whacked the agency's budget by 14 percent, singling out its work on the Mississippi for criticism -- but it did forge ahead with several ongoing structural projects, including a $60 million levee-and-pump scheme designed to close the gap in the New Madrid Floodway.

I visited the floodway last year, and it was easy to feel sympathy for the people who live nearby. It's not fair, they said. Every other town has a levee. Why should we have a gap?

The original answer, of course, was that the river in flood needs outlets for its excess water. That some areas need to be sacrificed so that more populated areas can be protected. That a levee would destroy even more wetlands along the river while encouraging even more development in a flood plain that wasn't supposed to be developed in the first place.

But it is developed. Almost the entire basin is developed.

Now what are we going to do about it? Michael Grunwald is a reporter on The Post's national staff.