Towns Gird for More Flooding : Disaster: Officials warn that new round of rain is on the way. Workers in St. Louis, other Mississippi River communities scramble to brace levees.

Volunteers, municipal crews and National Guard troops in St. Louis and towns along the Mississippi River worked furiously Wednesday to fortify levees as authorities warned that more rain and probable flooding were on the way.

“We have a very, very critical situation here,” said Julian Boyd, director of public safety in St. Louis. “We have crews working around the clock on deteriorating levees.”

Hundreds of residents living in homes surrounded by floodwater in the hardest-hit south end of town were urged by health officials to boil their drinking water as city workers drained overflowing sewer lines into the brimming River Des Peres, which winds along the southern city limits.

About 1,500 homes were without electricity, and several hundred others were without water. Underground mains continued to burst and buckled the streets. Flood victims lined up outside a federal relief station, where more than 700 families have sought housing, unemployment assistance and other government aid.

The Mississippi River, compassionate as a cobra, dropped by about an inch at the Gateway Arch in St. Louis--but nobody trusted it. It had crested overnight at a record 47.1 feet from the river bottom. More rain fell during the day, and experts said the additional rain could push it up again and melt more of its levees.

The flood kept killing. Its toll climbed to 33. The victims included a 9-year-old boy in Minnesota who died when he fell off a raft and an 86-year-old man in Missouri who drowned in four feet of water near his pickup truck. The homeless numbered nearly 40,000. Damage estimates topped $10 billion.

“More flooding is likely,” said Marty McKewon, a meteorologist at WeatherData Inc., a private forecasting service. “Rain will once again concentrate in the Mississippi Valley. Heavy rains are likely from south of St. Louis to Minnesota. . . . We see no break in the weather pattern.”

In Des Moines, water returned to fire hydrants, but leaky pipes caused another delay in restoring tap water. The city went dry after flooding swamped its water plant 11 days ago. Then, against orders, some people opened their faucets too soon and depressurized the entire system.

Plant manager L.D. McMullen said he had hoped to begin restoring tap water by Wednesday, but the leaky pipes spilled 30 million gallons. Now, McMullen said, water is expected to begin flowing to downtown faucets today--and throughout the city by the end of the week.

In St. Louis, volunteers ran out of sandbags, forcing street crews to scavenge toppled bags from a milelong stretch of the Des Peres that authorities conceded they no longer could defend. Maintenance crews at the airport were summoned to bag sand normally reserved for emergency use on runways.

“We are not standing down at all,” said city Fire Chief Neil J. Svetanics.

Residents of 160 homes, flooded when levees broke along the Des Peres late Tuesday, returned for essentials and valuables on Wednesday. Some came by boat. Others walked through waist-deep water in rubber waders. Health officials warned of infection and disease, but some people braved the water in shorts and sneakers.

Three bridges in south St. Louis remained closed, as did many residential streets. Police expected the arrival of 20 additional National Guard troops to patrol evacuated neighborhoods, where 60 troops already patrolled alongside 60 police officers.

Police reported no looting, but fears remained high among residents.

Some refused to leave their homes and formed groups to guard their streets. With the power turned off, clusters of neighbors kept refrigerators and fans running by jury-rigging hundreds of feet of extension cord over submerged streets and swampy back yards to gas-powered generators on porches and driveways.

“I stayed up all night patrolling the area,” said Jerald Smith, whose generator powered his house and three others. “It is better to be safe than sorry.”

Across the Mississippi in Granite City, Ill., and Alton, Ill., nearly 34,000 customers of the Illinois American Water Co. were ordered to boil their tap water. The utility has struggled for several days to protect a riverfront treatment plant in Alton by building a 200-foot-long levee with 1,300 tons of sand.

A company official said Wednesday that the utility issued an order to boil water as a precaution because flooding might have seeped into the treatment plant. “There is so much water out there,” Wayne Schlosser said, “we are taking every precaution.”

In the historic town of St. Genevieve, Mo., city officials issued an urgent call for volunteers to help fill and pile 60,000 sandbags along a weakening mile-long levee. The river wall was high enough to withstand a record 47.3-foot crest Wednesday, but water seeped through soft spots created when high winds sheared two feet off the top of the levee.

Hundreds of workers toiled throughout the day, but officials said they were worried that the effort would not be enough. Nonetheless, the town took a much needed break during the early morning to send off about 90 National Guard troops who were being replaced after weeks of defending the levee.

Residents lined Washington and Fourth streets, which had been festooned with red, white and blue balloons, to wave goodby. Each National Guard member was presented with a bouquet of flowers. A small band of high school students and other musicians played patriotic tunes.

“They worked shoulder-to-shoulder with townspeople for weeks,” said Jean Rissover, a city spokeswoman. “We all just fell for these guys. It was one of the most touching parades we’ve ever had.”

Down river, problems plagued the small town of St. Mary, Mo., where the river rose six inches before it crested Wednesday, pushing the town’s makeshift levee to its limit.

Fifty baggers shoveled sand, and 25 workers struggled throughout the night to reinforce the sandbag wall.

“It is getting to be nip and tuck all along here,” said Joann Donze, the city clerk.

Just across the Mississippi, in the farming town of Kaskaskia, Ill., residents awaited help from the National Guard to keep their levees intact.

In time, the crest of the river will pass Cairo, Ill., about 180 miles south of St. Louis.

There the Ohio River joins the Mississippi, and the channel widens and deepens. From Cairo south to New Orleans, most people should be safe, officials said. Robert Brown, a U.S. Army Corps of Engineers spokesman, said the Mississippi has not flooded New Orleans in 20 years.

Missouri

Officials in south St. Louis said massive levee breaks on the Des Peres late Tuesday were probably due to a combination of flash floods from heavy storms and rushing backwater from the cresting Mississippi. Crews worked to restore sections of the ruptured river wall, but they abandoned efforts on a one-mile span along Germania Street.

The levee break there dispirited residents in riverfront neighborhoods made up of small homes and narrow streets. They had built much of the levee by themselves last week and over the weekend. On Monday, several families had celebrated in the streets as the makeshift wall held its own.

But by Wednesday, the wall was down, streets were under water and basements and some ground floors were flooded.

“People worked for so long, and it took just minutes to destroy it,” said Barbara Socha, who surveyed the flood from her front stoop. “It is so sad.”

Several houses away, where the street dips toward the river and the floodwater was thigh deep, several neighbors waded from their homes holding stuffed pillow cases and garbage bags high above their heads. Behind them were Michael and Kim Bates, who had filled two laundry baskets with clothing.

The Bates had left their 6-year-old son with a relative and had rented an apartment not far away. They were ferrying their belongings back and forth. Michael Bates had piled a television, stereo and some appliances on some old tables in the living room, but he said he had no idea when he would be able to retrieve them.

“We are still debating what to do,” he said. “It is kind of shocking. We had to leave our house last night in a neighbor’s fishing boat.”

Others along Allemania Street refused to budge, even though several homes were surrounded by moats of water and could be reached only by squeezing along a narrow path through front hedges.

Ron Pleimann sat on the front porch of one of the moated homes and looked at his two-story house nearby. He and his wife, Stacie, had finally abandoned it in the early morning hours.

The Pleimanns gave up after a large wave came crashing through their front door and flooded their living room. The couple were furious. The wave was not from the raging river, but from a city bulldozer moving sandbags.

“It made a two-foot wave,” Ron Pleimann said. “It was like they were playing out there.”

Even after leaving, the Pleimanns kept a generator running on their front porch. A string of orange extension cords connected it to three nearby homes. Then it reached across the street, hanging three feet above the water, to provide power to neighbors there.

“That’s the kind of neighborhood this is,” said Pleimann, 29, a sheet-metal worker. “We built the levee together, and we continue to pull together. A neighbor came and rescued us last night with his boat, and now we are doing our part.”

Other States

In Manhattan, Kan., nearly 2,000 residents were urged to abandon their homes because of possible flooding caused by water released from swollen reservoirs. Officials pleaded for volunteers to fill sandbags in the rain.

About 300 people in Munjor, Kan., were advised to evacuate because of heavy rain.

Flash floods hit the Black Hills community of Deadwood, S.D.

“It rained super hard,” Albert Williamson, a cashier at a convenience store, told the Associated Press. “The street looked like a river was running down it.”

In Keokuk, Iowa, Secretary of Transportation Federico Pena inspected flood damage and told reporters that it was causing problems in national commerce.

Ships are leaving the West Coast without their regular loads of grain, Pena said, and shipments of parts to auto manufacturers have been delayed.