Roads were closed and land and homes flooded in many areas

Senior police, fire and ambulance officers will work with Environment Agency and council officials on Thursday to test responses to major flooding crises.

The agency said that while there were lessons to be learned from the downpours seven days ago, Exercise Noah had been planned for months.

It also says that fears about a summer drought are shrinking after the wet winter, although it still warns householders not to be "complacent" about potential water shortages.

Another prolonged dry spell would pose a further risk to water supplies Barbara Young, Environment Agency

More than 100 people will take part in the day-long exercise at Dyfed-Powys Police headquarters in Carmarthen in what will be the largest flood-related exercise to take place in Wales.

Agency spokesman John Mosedale said: "There will be a debrief from last week but they really are quite unrelated.

"This is an exercise for a much bigger scenario. The floods last week were not uncommon.

Fields around Llandeilo were underwater

"What we will be looking at is scenarios many people will not have experienced before."

One of the worst disasters in living memory in the region was the collapse of the Glanrhyd railway bridge near Llandeilo in 1987 which claimed four lives.

Mr Mosedale said the scenarios that would be played out would be on a similar scale.

"Basically it will be, here's a scenario, now answer these questions about what sort of response you think is needed," he added.

The agency has also said worries about the low level of water in some reservoirs in south east Wales during the autumn and winter are no longer a concern.

Heavy rainfall during the last three months mean the risk of water supply shortages next summer are now no higher than normal.

Chief executive Barbara Young said: "Although the situation is now looking better, in spite of floods in some parts of the country, we cannot afford to be complacent.