Lingering Rains Stall Midwest Recovery, Spark New Flooding : Waterways: Storms keep levels too high for resumption of barge traffic. Dams and locks are still out of commission and levees overtaxed.

Sporadic rainstorms slanting across the upper Midwest over the last week have slowed the snail-like retreat of flooded rivers, lengthening delays to barge traffic and navigation recharting efforts on the Mississippi.

The Mississippi actually rose at Keokuk, Ill., and a few other river points over the weekend. And a storm that dumped as much as 10 inches of rain early Monday in sections of southern Minnesota and northern Iowa sparked flash floods that swept across roads and towns that had been inundated by last month’s storms.

Meteorologists and river specialists said the recurring rainfall has not approached the staggering nightly amounts that choked the rivers last month. But the rains have kept river levels high enough to stall the resumption of river traffic and maintain pressure on levees already saturated after a month of record flooding.

“We had some rainstorms last week that were doozies,” said Denise Yale, a spokeswoman for the U.S. Army Corps of Engineers Rock Island, Ill., district. “It’s not enough to cause new flooding but it’s keeping the river up high longer than we’d like.”

Cloudbursts in northern Iowa and southern Minnesota forced residents to sandbag their communities--some for the third time in a month.

A dozen residents left homes in Charles City, Iowa, and 200 volunteers worked to sandbag against the surging Cedar River.

In Iowa City, where the Iowa River flooded over for the second time in a week, officials said they were more prepared to deal with the raging water. Last Monday, a flash flood caused by a sudden rainstorm overwhelmed the city, pouring water into more than 150 businesses and 160 homes.

Iowa City officials criticized the Army Corps last week for failing to reduce the flow of water from the nearby Coralville Dam during the storm. Sunday night, city administrator Kelly Hayworth said, the Corps acted quickly.

“Last week, our streets were closed for a day and half,” he said. “This time, we were able to reopen them in three hours.”

On Monday, Mark Ziemer, a hydrologist at the National Weather Service’s North Central River Forecast Center in Minneapolis, said that recent rains have lengthened the expected duration of flood stages on the Mississippi.

A week ago, forecasters had been expecting the river to return to normal by late August or early September. It will now be mid-September before the Mississippi will reach its regular levels, Ziemer said.

The Mississippi has been falling at varying rates along the length of its shelf: On Sunday, the river dropped only a tenth of a foot near Burlington, Iowa, while it fell a half-foot at Keithsburg, 40 miles to the north. And at Keokuk, it rose several tenths, Ziemer said, as a result of storms that pounded northern and eastern Iowa over the weekend.

Army Corps officials had been hoping that its system of river dams and locks north of Cairo, Ill., would be repaired by the end of this week. But on Monday, the locks were still closed north of Lock 22 at Saberton. Mo., and Corps officials conceded that high water had prevented them from even getting close enough to inspect damage at some of their southern locks and dams.

Most of the locks have suffered water damage to key electronic control panels and erosion of sand and sediment from beneath lock supports, said Teresa Kincaid, an Army Corps civil engineer.

“Some of our locks had as much as eight feet of water over their lock walls,” said Army engineer Denny Lundberg.

Without a functioning lock system, barges continue to be stalled on the Mississippi. Although the dams and locks have been reopened north of Saberton, river traffic is still closed as far north as Keokuk--largely because Coast Guard officials fear barge wake could breach the few levees still standing in southern Illinois and Missouri.

In Ste. Genevieve, Mo., where a sodden 50-foot-high flood wall has held against a month of high water, officials are insistent that river officials make sure damage will be minimal before they allow barge traffic to resume.

“We’re still touch and go here, and the last thing we need right now is river wake,” said Mayor Bill Anderson.

A task force of Army Corps and Coast Guard officials and barge industry leaders has proposed sending a test tow barge down the river soon to see how much wake is produced on high water. But because the river is so high, officials have yet to set a date for the experiment.

More than 50 towboats and 2,500 barges are stalled on the river, and their paralysis is costing the river transportation industry as much as $4 million a day, said Laura Sanders, an assistant at the American Waterways Operators Assn. in St. Louis.

High water has also created obstacles for the Army Corps’ recharting of the river. A Corps vessel outfitted with sensitive electronic gear plied as far south as Quincy, Ill. last week, taking soundings from the river bottom.

But the boat had to turn back at Quincy, said Corps dredging coordinator Dick Baker, because high water was continuing to spread sediment through the channels, making accurate readings impossible.

“We could take a reading today, but tomorrow the channel depths might be completely different,” Baker said. “We have to wait until the river drops enough so that the silt begins to settle.”