Photo courtesy of California Department of Water Resources A levee along the Middle River in the Sacramento-San Joaquin Delta breaks in June 2004.

For millions of Americans living in flood-prone places, all that stands between the waters of mayhem and safety is a pile of dirt.

Earthen berms, dikes and levees, identical to those overtopped and breached in dozens of places along swollen rivers in the Midwest during the past two weeks, make up the majority of flood protection efforts across the United States.

Well before record floods overwhelmed at least two dozen levees in the Mississippi River watershed, government officials at all levels have raised concerns about the ability of such structures to protect property and lives.

A growing list of levees across the country is being found wanting as tougher scrutiny from the U.S. Army Corps of Engineers, state regulators and private engineering firms reveals defects in design and maintenance.

Even where levees are well-maintained, as those in the flood zone have been in most instances, officials note that the likelihood of flood levels rising higher than the tops of the berms seems to be increasing because of a combination of more intense storms and changes in land use. Most of the levees that have been overtopped were built lower because they defend mostly farmland rather than cities.

However, places like Cedar Rapids, Iowa, and Iowa City had rivers crest more than 10 feet higher than levels reached in the great flood of 1993, making it impossible to pile sand bags high enough or fast enough on levees to keep the water out.

National levee inventory

The corps alone issued more than 13 million sandbags to battle the flooding, enough to make a line from Washington, D.C., to San Francisco.

Yet the corps and the Federal Emergency Management Agency, which is requiring levee owners to certify their dikes' ability to hold back at least a 100-year flood as part of a national program to redraw flood hazard maps, are backing away from the notion that communities can sandbag their way to safety if levees prove too short or develop leaks.

Congress, in light of levee failures in New Orleans in 2005 and the potential for similar catastrophes in many parts of the country, recently ordered the corps to conduct a first-ever national levee inventory.

A review by Scripps Howard News Service of levee oversight and funding at the state and national levels suggests the new focus still may not be sufficient to overcome decades of neglect.

Among the findings:

n No one at any level of government knows where all the levees are, much less the condition of thousands of the structures. By some estimates, there may be from 20,000 to 30,000 levees scattered across the country, but no one is sure.

n Maintenance of levees, even those operated by the corps itself, is years and billions of dollars behind schedule.

n Fewer than half the states have agencies responsible for levee safety, and only 10 have statewide listings of flood control works.

n Relatively few new levees have been built in recent years. Many of those that have been built are not designed to protect existing homes and businesses but to defend new development in flood plains, against the advice of conservationists and emergency management officials.

Americans at risk

"The levees are already bad, and they are going to get worse,'' said Mike Parker, a former civilian head of the corps and now a lobbyist in Washington. "This is not a joke. We know this is going to happen. The levees were built in the first place because there were (flooding) problems."

Parker, a former congressman from Mississippi, was fired from his corps position in 2002 after warning Congress that a $2.8 billion budget cut to the corps sought by Bush administration officials would have a "negative impact" on the national interest.

Equally troubling to flood control experts: Many Americans living in areas with sub-standard levees may have no clue they're at risk.

"Many of the property owners behind those levees may not even be aware that the levee protecting them is poor and likely to fail," Larry Larson, executive director of the Association of State Floodplain Managers, told Congress last year in testimony calling for a levee inventory.

"Many private levees were built to protect farmland from frequent flooding or to improve cropping of the land. Over time, development of homes or other buildings has taken place in the areas which would be inundated if those levees overtop or fail," Larson said.

Absence of information

It was disastrous flooding in the Mississippi Valley from the turn of the century through the 1940s that thrust the corps into flood protection design, construction and maintenance, roles that continue today, although at a diminished pace.

The corps now is responsible for about 2,000 levees, some federally owned or built. Others are locally owned and maintained but are included in a special national rehabilitation and inspection program that guarantees the government will help rebuild structures that fail.

It was from this group of levees that the corps in late 2006 identified 122 projects around the country that have major maintenance problems ranging from animal burrows and erosion to faulty culverts and movement of flood walls.

Levees actually owned and maintained by the corps made up 18 percent of the list of problem levees, even though they represent less than 2 percent of all the levees reviewed.

Eric Halpin, the corps' special assistant for dam and levee safety, said the seemingly disproportionate number of deficient corps-operated levees stems from the absence of information about the rest of the nation's dikes.

Unknown vulnerabilities

While the corps is attempting to tend to all its levees, maintenance and repairs for many are backlogged because of budget restrictions.

Steve Stockton, deputy director of civil works for the corps, discussed the problem with officials at a June conference on levees in St. Louis. "The bottom line is we have $60 billion in needs and authorized projects, and we get $1.5 billion to $2 billion a year to chip away at that."

The corps' budget for operations and maintenance of levees along with new construction has been shrinking or flat for much of the past decade. Congress approved $2.2 billion for this year and the corps has asked for $2.6 billion for the 2009 fiscal year that begins in September.

While the known deficiencies in levees are worrisome enough, equally troubling are the unknown vulnerabilities.

"What we know that we don't know is a big concern. We expect additional deficiencies to be identified," Halpin said.

"Our portfolio is incomplete until we find the rest of the levees out there that aren't under any federal authority for inspection or assessment,'' Halpin said.

Under last year's water resources legislation, the corps is supposed to work with other federal, state and local agencies to develop a national levee inventory.

Patchwork of protection

Recent surveys by the Association of State Dam Safety Officials and the Association of State Floodplain Managers found that only 10 states keep listings of levees within their borders. Only 23 states report having agencies responsible for levee safety.

The trouble with levees and with the corps' historic approach to building them, many critics say, is that the structures are a patchwork of protection of varying height and quality extending over thousands of river miles. Adding to the problem is the limited amount of inspection the corps is able to conduct.

Halpin notes that while the National Levee Safety Program Act gives the corps authority to inventory levees, "it didn't really expand our authority to inspect levees." That's still left either to the states or the levee owners themselves.

The legislation authorized the corps to spend up to $120 million over six years on the inventory, but Congress has yet to appropriate any money for the work itself. Next year, the corps' budget calls for spending just $10 million on the effort.

"It's typical that Congress moved quickly to identify the problem and now is slow in coming up with the money to follow through,'' said Gerald Galloway, a professor of engineering and levee expert at the University of Maryland. "This can't be entirely a federal problem. Flood plain management and land use is and should be a function of state and local government."'

System favors new levees

In some areas, retreat has been national or state policy.

After the 1993 Mississippi-Missouri basin floods, the Federal Emergency Management Agency spent more than $150 million to buy out or move more than 12,000 property owners whose land had been submerged by the floods.

However, the lure of easily developed bottomland is still powerful, and the corps' cost-benefit system for evaluating projects still favors new levees to protect new development.

In the St. Louis metropolitan area, since 1993 some 28 square miles and at least $2.2 billion in new construction has gone up on land that was under water 15 years ago but now lies behind newly built levees.

"Building a levee for a community simply certifies' that this is a great place to build more things," said Robert Criss, a professor of earth and planetary sciences at Washington University in St. Louis. "These structures are not infallible, and when the levees fail — and they will, carefully though they are built — we just have more infrastructure in harm's way. It's not a very thoughtful approach."