Much of southern England is underwater thanks to a record-breaking deluge that has fallen over two months. More than 5000 homes have flooded in the Thames valley and Somerset. Many of the people affected complain that rivers should have been dredged to allow the water to escape faster. But hydrologists say dredging alone would have made little difference. The only way is to manage entire catchment areas, or in the case of Somerset, perhaps build an artificial lagoon.