LONDON (AP) -- Emergency workers battled rising waters Monday to rescue people trapped by floods that swallowed large swaths of central Britain. Roads were submerged, and tens of thousands of people were left without electricity and drinking water.

Torrential rains have plagued Britain over the past month -- nearly 5 inches (12 centimeters) fell in some areas on Friday alone -- and more downpours were expected until at least Tuesday. Officials warned that the western section of the River Thames -- some 80 miles (128 kilometers) from London -- was on the verge of bursting its banks.

London itself is protected from flooding in the east by the Thames Barrier, the world's largest moveable flood defense. The barrier closes to seal off part of the upper Thames from the sea. To the west, London is protected by several flood defense measures including the Jubilee River, a 7-mile-long (12-kilometer-long) flood diversion channel.

"People look at me and say I look fine, but inside I'm all churned up,'' said Sylvia Williams, a 69-year-old widow who was among about 50 elderly people evacuated to a stadium from a retirement community overlooking the River Ock on the outskirts of Oxford.

The stadium was stocked with blankets, food and bedding for up to 1,500 people.

The Thames water levels in Oxford were expected to peak at midnight, which could make flooding worse in areas, the Environment Agency said.

Cars were submerged and streets turned into canals in flood affected areas. Thousands were forced to leave their homes and businesses.

Among the hardest hit was the medieval market town of Tewkesbury, 110 miles (180 kilometers) northwest of London, where the cathedral and a few blocks of nearby houses stood like an atoll amid a vast stretch of muddy water.

"It was just devastation -- total chaos, cars floating past, rubbish, all kinds,'' said John King, a 68-year-old retired fire fighter from Tewkesbury who said the flood sounded like a train. "You just can't stop water of that power.''

He said he saw goldfish swimming in his driveway.

The Severn Trent Water company said at least 350,000 homes in Gloucestershire would be without water after flood waters shut down a water treatment plant.

The last time Britain saw similar flooding was in 1947, according to the Environment Agency.

No deaths have been reported.

Prime Minister Gordon Brown announced increased funding for flood and coastal defenses across the country during a tour of the flooded Gloucestershire region, in the west of England.

Much of Britain's infrastructure dates back to Victorian times.

"It is pretty clear that some of the 19th century structures and infrastructure and where they were sited is something we will have to review,'' said Brown, who succeeded Tony Blair as prime minister less than a month ago.

The monsoon-like rainfall over the past month has severely affected transport and threatened water supplies.

Some 70,000 people were left without clean drinking water as a result of flooding at water treatment plants and rainwater seeping into treated supplies. Tens of thousands more were at risk of losing fresh water supplies.

Some residents lined up for free water at local grocery stores. Others waited for water trucks to distribute water.

More than 100 Royal Navy sailors were helping build flood defenses with sandbags and trying to improve the drainage by wading into the water and lifting the manhole covers.

Insurance companies said the damage from flooding in June and July could reach hundreds of millions of pounds (euros, dollars).

"This emergency is far from over, and further flooding is extremely likely,'' Environment Secretary Hilary Benn told legislators.

Meteorologists said water levels were expected to peak Tuesday or Wednesday, meaning further water and electricity shortages are likely.

"The situation is looking critical at the moment,'' Environment Agency spokesman Joe Giacomelli said. "Unfortunately the misery is set to continue.''

The weather facing Britain is consistent with conditions caused by the La Nina weather system, which is caused by cooling ocean waters and leads to extreme weather, Britain's Met Office said. However, scientists said there was no clear explanation for the unusually long spell of wet weather.

Climate change may be culprit, said Tim Evans of the Chartered Institution of Water and Environment Management, adding that the situation matched predictions of how global warning would affect Britain.

Britain had one of its hottest and driest summers on record last year.

"What we now think of as extreme events will occur more often than in the past, and the extremes will get more extreme,'' Evans said.