Flooding from rivers is usually the result of excessive rain entering streams and other minor watercourses and running into rivers. Rivers vary in the way they respond to excessive water depending on their capacity and available access to the floodplain.
Any watercourse that is big enough to cause significant flooding is designated by the Environment Agency as ‘main river’ – but this does not necessarily just mean larger rivers – smaller watercourses can also cause serious flooding.
When flood waters have access to the floodplain it allows storage of excessive water and slows down flow in a river. However when development has taken place on the floodplain this increases the risk of flooding. Sometimes developers who are allowed to build on floodplain land are asked to contribute to the cost flood alleviation measures as part of the planning process.
Flooding from rivers is usually known as the river ‘going out of its bank’.
When forecasts show there is a possibility of flooding from rivers the Environment Agency issues flood warnings to householders/businesses that may be affected. However not all areas subject to possible flooding are signed up to receive flood warnings from the Environment Agency. The annual public awareness campaign run by the Environment Agency encourages householders at risk to join the flood waning service – now known as Flood Warnings Direct. Households and businesses can now sign up to receive flood warnings via a variety of methods such as to their mobile phone or computer, as well as to a land line in their property.
People who own land adjacent to rivers (known as riparian owners) are responsible for the smooth passage of water through their land. They must not allow blockages in the watercourse and should remove any obstructions that appear. These can be natural blockages such as fallen trees or overgrowth on the banks or rubbish that might be dumped in the watercourse or flowed downstream from another area.