FLOODWALL SEPARATION NOT SERIOUS, SAYS CORPS

When Gerald Boren noticed what appeared to be a crack in the floodwall at Water and Independence streets, he was concerned enough to phone the U.S. Army Corps of Engineers.

No need for worry, said the corps, which is monitoring the spot to make sure no further changes occur.

The potential problem is not a crack but a slight separation at one of the many joints in the 4,000-foot-long wall that keeps the Mississippi River out of downtown Cape Girardeau. Dedicated in 1964, the wall moved at the joint and at another farther north since the wall was built.

The joint also looks suspicious because of a phenomenon called spalling, wear and tear that occurs when concrete freezes and thaws repeatedly. Spalling leaves the joint looking as though it is chipping apart.

Alan Hunter, area engineer for the corps, says the one-half-to-three-quarter-inch separation occurred eight to 10 years ago and has not increased since. The movement could have occurred because of different soil conditions under the concrete panel.

Floodwalls are not solid but are built in sections that can expand and contract because the earth moves, Hunter said. "All structures move. When you hear creaks at night, that's your house moving."

The joint is near a point where the wall changes directions, shortening the panel. "Whatever caused it to move moved it because it's a lighter section of wall," Hunter said.

The wall is nearing the end of its design life -- 50 years -- but Hunter says it remains structurally sound and could last two or three generations.

The corps checks the length of the wall twice a year. During the Flood of 1993, water could be seen leaking through the separation but not in significant amounts.

Hunter calls the separation "an anomaly." The wall is in good shape as long as the water stop, a piece of plastic that runs from one side of the joint to the other, remains intact, he says.

"It's a very sound floodwall we've got down there."

If the water stop should tear, the joint probably would require a repair.

Boren, who has worked in construction, called the corps because he thought the footings were settling. He was not concerned that the floodwall would give way.

Hunter says a catastrophic failure of the wall is a farfetched idea.

"There is no reasonable chance that it would give way," he said. "We have people watching it that have watched it for years and years, and we have safety factors built into our structures."

The safety factors built into the floodwall make it three to five times as strong as it needs to be, he said.

The floodwall is maintained by the Main Street Levee District. District President Andy Juden says the wall has never had any structural problems and so far has required only routine maintenance. "There has been nothing close to a failure," he said.

Hunter is originally from Louisiana, where the Mississippi is three times its size here but is held back by earthen levees. During floods there the corps receives reports of worms, gophers or armadillos undermining the levees, but he said they never turn out to be true.

"It just doesn't happen," he said. "The Corps of Engineers stays on top of these things."

Hunter wouldn't say a failure of the wall is impossible, but it's certainly improbable, he said.

"The U.S. Army Corps of Engineers will never defeat nature, but as long as nature acts like it's supposed to we're going to know what's going on."