* Bush visits flooded Iowa, returns to Washington
* $4 billion in U.S. disaster fund said adequate
* 23 Mississippi River levees overflow, more at risk
* Corn prices retreat from record highs
By Tabassum Zakaria
CEDAR RAPIDS, Iowa, June 19 (Reuters) - President George W. Bush got a close-up view of damage from the worst Midwest flooding in 15 years on Thursday as his administration promised funding from a multibillion-dollar disaster relief fund.
The price tag from the slow-rolling calamity mounted as flood waters surged over and through levees along the surging Mississippi River.
The cost of the flooding across the U.S. corn belt will be felt by consumers worldwide in terms of higher food prices, and in business losses yet to be toted up.
"I know a lot of farmers and cattlemen are hurting right now," Bush said at an emergency center in Cedar Rapids, among the cities hit hardest by this week’s flooding. "It’s a tough time," he said before taking a helicopter tour of flooded areas with Iowa Gov. Chet Culver.
After viewing the Cedar River, which jumped its banks and flooded several square miles (kms) of Cedar Rapids, Bush toured a construction company used as a staging area in flooded Iowa City and saw a wall of sandbags stained brown by the river.
During the trip to Cedar Rapids with Bush, Federal Emergency Management administrator David Paulison said the $4 billion currently in FEMA’s Disaster Relief Fund should be "more than enough" to provide federal aid.
White House Budget Director Jim Nussle, a former Iowa congressman, said Bush would not announce new aid immediately, but was keeping an eye on the U.S. House of Representatives debate on a war funding bill that included $2.65 billion to replenish the disaster relief fund.
In a sign of the political importance of heartland states, the Republican hoping to succeed Bush in the White House, John McCain, paid a visit to Columbus Junction, downstream on the Iowa River from Iowa City, where Bush stopped before returning to Washington.
McCain praised the flood-fighting efforts and said he was confident an aid package will move quickly through Congress.
Earlier this week, likely Democratic presidential nominee U.S. Sen. Barack Obama of Illinois helped on a sandbag line on the Mississippi River in his home state.
COST COULD RISE
Culver has said he anticipated $2 billion in federal aid. Ultimately, the cost of the disaster may rival that of 1993 Midwest floods that caused more than $20 billion in damage and 48 deaths.
Twenty-four deaths have been blamed on flooding and violent storms since late May as rivers overflowed their banks. Another 40,000 people have been forced from their homes.
The high cost of recovery might warrant more federal help, some residents said. "It might behoove the government to consider spending $5 billion or $6 billion less on foreign wars and invest that money on helping out people here instead," said Dave Spitaleri, owner of the Railsplitter Inn in Hull, Illinois, along the Mississippi River.
U.S. government disaster aid would help with repairing or replacing washed-out roads and rail lines and with the largely uninsured cost of damage to inundated businesses and homes.
Union Pacific Corp, the No. 1 U.S. railroad, said on Thursday it had reopened an east-west track through Iowa, allowing limited traffic. A pair of lock and dams reopened on the Mississippi River, though more than 240 miles (386 km) of the vital waterway remain closed, stranding scores of barges.
Days without rain have allowed rivers and creeks to recede in Iowa, Illinois, Wisconsin and Indiana, revealing the scope of the multibillion-dollar flood disaster. Scattered rainstorms were forecast, but nothing like the deluges that dumped a foot (0.3 metre) of rain on parts of the region this month.
The final destination for all that flood water was the Mississippi River, which had breached or overtopped 23 levees along its north-south route.
The U.S. Army Corps of Engineers said 48 levees protecting more than 285,000 acres (115,335 hectares) of cropland from Dubuque, Iowa, to St. Louis, Missouri, were overflowing or at high flood risk.
Thousands of people filled sandbags and bulldozers pushed piles of sand to patch up leaking levees, as the raging current sought an outlet underneath, over or through the earth and sand embankments.
Corn prices retreated on Thursday, after setting a record high above $8 a bushel on the flooding that has submerged or stunted crops on millions of acres (hectares). According to crop analysts, 5 million acres (2 million hectares) of cropland mostly planted to corn and soybeans have been ruined.
"If we get good weather we could still have decent crops," said Vic Lespinasse, analyst for GrainAnalyst.com.
"The levees are still breaking and it’s tragic for the people involved," he said. "But if we have another weather problem, we could take off like a rocket." (Additional reporting by Nick Carey in Hull, Lisa Shumaker and Sam Nelson in Chicago; writing by Andrew Stern; Editing by Doina Chiacu)