Floods and heat torment the US

THE VASTLY different, but closely related, demons of flood in the Midwest and record heatwave on the Atlantic seaboard continue to torment the United States. Yesterday the level of the bloated Mississippi and Missouri rivers rose yet further, while 21 people have died from the heat from the Carolinas to as far north as Boston, Massachusetts.

But for all the problems caused by the excessive heat - Washington and New York have just registered three successive 100F-days for the first time since 1948, with no major respite in prospect - the consequences of the current floods in Illinois, Iowa and Missouri will be much longer-lasting.

As of yesterday, at least 12 people had drowned and 20,000 had been evacuated from their homes. Over 450 square miles of land and low-lying towns have been turned into lakes, and total damage already tops dollars 2bn ( pounds 1.3bn). President Bill Clinton has now declared the worst affected parts of Iowa, Missouri and Illinois major disaster areas, qualifying for federal aid, while Vice-President Al Gore was due to visit the stricken areas today.

The Mississippi and Missouri have breached levees along hundreds of miles to the north and west of their confluence just above St Louis. The city itself looks safe. Although the Mississippi is forecast to peak at 45 feet, two feet above the previous record set in 1973, central St Louis is protected by flood walls able to cope with 52-foot floods.

But tributaries are starting to cause problems of their own. The Iowa capital of Des Moines, where the swollen Raccoon and Des Moines rivers meet on their way to join the Mississippi, yesterday saw insult added to injury as flood waters smashed through a levee and overwhelmed a water decontamination plant. About 250,000 sodden Des Moines residents will be without drinking water for at least a week.

Both heatwave and floods are opposite sides of the same meteorological coin. The sweltering conditions in the east are the work of a gigantic high pressure system, immobile over the area for a week now, which has blocked the normal west-to-east flow of weather across the US. Instead storms have been locked over the Midwest, fed by a stream of moist Gulf air sent northward by the 'Bermuda high' anti-cyclone.

Almost certainly, the worst of the flooding is still to come. The next 48 hours promise some let-up in the rains, but thereafter fresh deluges are likely over the upper Midwest.

With the floods come other hazards. Contaminated water has spread the risk of disease, and in the combination of floods and heat, mosquito populations are soaring. In some areas, free typhoid injections are being offered. But some flood problems are entirely human in origin. In East St Louis, on the Illinois shore of the Mississippi, officials found thieves had stolen a flood gate weighing several tons. A replacement failed to arrive, forcing the authorities to move 200 tons of earth and rock to shore up the city's defences.