June 26 (Bloomberg) -- Three days of rainfall in the Midwest are leading to predictions of higher crests for some cities along the Mississippi River and may trigger a second round of flooding for already-swamped communities.

Parts of northeast Missouri were drenched by more than 8 inches (20 centimeters) of rain over the past three days, and more storms are forecast for tomorrow, according to the National Weather Service. Cities on the Mississippi were already battling the worst floods in 15 years before this week's soaking.

``We're looking at projected rainfall through Sunday and it is of concern to us,'' said Glenn Cannon, assistant administrator in the disaster operations directorate for the Federal Emergency Management Agency in Washington.

Since mid-May, storms and severe weather have killed at least 24 people, flooded more than 3.4 million acres of land and caused billions of dollars of damage to crops. The floods also prompted President George W. Bush to declare more than 103 counties in Illinois, Missouri and Iowa disaster areas, making them eligible for federal assistance.

Yesterday, Bush named 22 Missouri counties disaster areas, as well as the city of St. Louis, according to a statement released by the state's Republican governor, Matt Blunt.

Federal Assistance

FEMA has paid out about $115.2 million to homeowners in Iowa, Indiana, Wisconsin and Nebraska to help them recover from the flooding and severe weather, agency spokeswoman Elizabeth Childs said today.

Clarksville, Missouri, Mayor Jo Anne Smiley said her city needed the declaration because it had already spent about 25 percent of its $400,000 annual budget fighting the flood.

Floods contributed to $8 billion of damage to the nation's crops in the first half of the year, the American Farm Bureau estimated in its June Market Update. About half of that was in Iowa and $1.3 billion was in Illinois, according to a farm bureau statement.

In Missouri, where more than 100,000 acres of farmland are submerged, agricultural losses are about $900 million and rising, said Kelly Smith, marketing commodities director for the Missouri Farm Bureau in Jefferson City.

Missouri Flooding

Rains throughout the state have caused localized flooding in addition to the deluge caused by the Mississippi and its tributaries, which will likely increase damage estimates in coming days, Smith said.

``We were only at about 90 percent of the corn and 50 percent of the soybeans planted'' when the floods hit the state, Smith said. ``We have a lot of acres that may not get planted because of all the wet weather.''

In Clarksville, a city of about 490 that is 62 miles (100 kilometers) north of St. Louis, residents live behind a makeshift wall of sandbags and dirt along its main street.

``It is a siege,'' Smiley said. National Guard troops may have to leave town for other areas and residents are learning to maintain the wall, which may have to stand for weeks.

The river at Clarksville initially crested three days ago at 36.7 feet (11.2 meters), almost 12 feet above flood stage. After the latest rainfall, the city is now forecast to have a second crest at about 36.7 feet in the next day, within about a foot of the 1993 record.

St. Louis Crest

In St. Louis, a crest of 38.7 feet is expected by June 30, according to the National Weather Service.

The latest round of storms comes after parts of Iowa received as much as 15 inches of rain in the past month, triple the typical amount. That rainfall led to record crests on rivers in several cities in Iowa, including Cedar Falls, and swelled the Mississippi as the deluge poured downstream.

The Midwest storms are ``on the extreme end of what is considered normal, Ben Miller, a meteorologist with the service, said from St. Louis.

The past few weeks' precipitation, coming after melting snow saturated the soil earlier in the year, has made it almost impossible for the ground to absorb more water, he said.

As a result, any additional rain will likely run off into rivers and streams, he said.

``Things are going to get a little worse before they get better,'' Miller said.

The revised forecasts for river crests have caused officials to stack sandbags around a mobile home park in Winfield, Missouri, about 36 miles north of St. Louis, said Nicole Dalrymple of the U.S. Army Corps of Engineers in St. Louis. The river may not crest for another day at Winfield, climbing almost another 4 inches to 37.4 feet.

A nearby levee is in danger of failing and while the mobile home park is on high ground, officials fear that the extra rain may push flood waters to that level, she said.

The Midwest floods have inundated cropland, helping drive the price of some grains higher. Corn, which reached a record $7.915 on June 16, has more than doubled in the past year.

Soybean futures have jumped 90 percent in the past year, reaching a record high of $15.865 on March 3.

To contact the reporter on this story: Brian K. Sullivan in Boston at bsullivan10@bloomberg.net.

Last Updated: June 26, 2008 15:41 EDT