Joe Clark, right, and Eddie Chadwick help friends by paddling valuables out of a flooded neighborhood in Osawatomie, Kan., Sunday, July 1, 2007. [AP]

Crude oil spilling from a refinery into one flooding river contributed to the mess.

The Kansas National Guard was sent to help with a mandatory evacuation of Osawatomie, a small town in eastern Kansas and one of the hardest-hit communities in the region. The town evacuated 40 percent of its 4,600 residents after two rivers ¡ª Pottawatomie Creek on the town's south flank and the Marais des Cygnes on the north ¡ª rose out of their banks.

"I think the Marais des Cygnes will be OK," Mayor Philip Dudley said. "I'm still concerned about Pottawatomie Creek. It's supposed to get over 49 feet on Monday."

Kansas Gov. Kathleen Sebelius planned to survey the damage Monday.

Rain had mostly stopped falling Monday in Kansas, but the National Weather Service extended a flash flood watch for six counties in the state's southeast corner because major flooding continued on area rivers.

Levees and dikes around Osawatomie held after volunteers reinforced them with sandbags, but water pooling in low-lying areas overwhelmed pumps and flooded neighborhoods.

"It's going to be a few days before we get some of the higher rivers to come down," said Maren Stoflet, a National Weather Service meteorologist in Pleasant Hill, Mo.

Problems created by the flooding were compounded by a spill of more than 42,000 gallons of crude oil from the Coffeyville Resources refinery into the Verdigris River, said Sharon Watson, spokeswoman for the Kansas Emergency Management Agency.

The federal Environmental Protection Agency had teams on the scene of the spill, said Jim Miller, Montgomery County emergency manager. About a third of the homes in Coffeyville and a quarter of homes in Independence had been evacuated, he said, and water intakes for Coffeyville, Independence and Elk City had been shut down.

Coffeyville Mayor Virgin Horn said his own house was submerged.

"We're very concerned," Horn said. "It's chemicals mixed with water."

The oil was expected to flow down the swollen Verdigris River into Oklahoma and Lake Oologah, said Maj. Gen. Tod Bunting, the Kansas state adjutant. The lake, about 30 miles northeast of Tulsa, provides flood control in the Verdigris and Arkansas river basins and is used for boating and fishing.

However, there is a good chance the spill will dissipate before it reaches the lake, said Ross Adkins, a spokesman for the Tulsa District of the U.S. Army Corps of Engineers.

While Kansas was getting a break from the weather Monday, more rain was scattered over Texas and eastern Oklahoma on Sunday and Monday, the latest in nearly two weeks of storms that have inundated parts of Kansas, Texas and Oklahoma. Eleven deaths have been blamed on the storms and flooding in Texas, where two men are missing.

The overnight rainfall flooded a few roads in South Texas but there were no reports of stranded motorists or evacuations, authorities said.

During June, the weather service measured more than 11 inches of rain at Dallas-Fort Worth International Airport, about a half-inch shy of the 1928 record. The Texas town of Marble Falls, northwest of Austin, collected about 18 inches in one night last week.

At least 200 people were still displaced from their homes near the Brazos River in Texas' Parker County.

Although some flooding eased in northern and central Texas, officials cautioned that more was possible.

"It's a continuous up and down situation," said Shawn Scott, Parker County emergency management coordinator. "This could be ongoing for the next few days."

Oklahoma also has suffered flooding, with some of the worst on Sunday near Bartlesville, where the Caney River was more than 3 feet above flood stage.

Amtrak's Heartland Flyer passenger rail service between Oklahoma City and Fort Worth was halted Sunday because of flooding in north Texas, said Terry Angier, a spokeswoman for the Oklahoma Department of Transportation. Passengers were placed on buses.