Sergeant Jeff Windmiller of the Louisiana Police Department rides on a boat through the flooded streets in Louisiana, Missouri June 19, 2008. [Agencies]

The ripple inflation effect on global food prices as US prices soar has alarmed everyone from central bankers to food aid groups. Fears that livestock herds will be culled because of soaring corn feed prices may push meat prices up for years.

Flood aid and relief issues also poured into the political arena.

Democratic Party presidential candidate Barack Obama said on Saturday that Midwest levee breaks and flood damage were reasons to back his $60 billion spending proposal to modernize US roads, bridges and waterways. Much of that would be financed by downsizing US commitments in Iraq, he said.

of his state had been hit by tornadoes or flooding, including 340 towns, with extensive damage to road and rail lines at a cost of "tens of billions of dollars."

Chemicals from farm fields and other toxic substances left behind as waters recede have created a potential health threat. Damaged municipal sewage systems in places like Cedar Rapids, Iowa, were releasing raw sewage into rivers. But drinking water supplies remain unpolluted in most areas, officials said.

In Cedar Rapids, where officials have said 4,000 homes were damaged by this month's flooding, government buyout plans estimated at $80 million or more were under discussion.

The Federal Emergency Management Agency has 43 disaster recovery centers open across the flooded areas of Iowa, Illinois, Missouri, Indiana, Wisconsin and Minnesota.

In Iowa, Indiana and Wisconsin, 56,096 registrations for assistance have been received from disaster victims and more than $115 million approved for housing assistance and other disaster-related needs. More than 5,600 households have filed flood insurance claims.