River or ditch flooding normally occurs as the result of a storm or series of storms over the whole of a river's catchment. These storms are usually of longer duration and are less intense than the storms that cause flash flooding. Normally the Environment Agency is able to issue several hours' warning of the likelihood of river flooding using their automatic flood warning system, and by radio and television messages. You can call their Floodline on 0845 988 1188 to find out the latest information on river and coastal flooding, and register to receive automated flood warning messages.
The rivers, streams and ditches are the responsibility of the riparian landowners who own land on either bank. If your property is adjacent to a watercourse of any description you are a riparian owner and should be maintaining it regularly. This will have the benefit of reducing the risk of flooding from the watercourse at times of wet weather - both for you and your neighbours.