| Term |
Definition |
| Catchment |
An extent or an area of land where all surface water from rain, melting snow or ice converges to a single point at a lower elevation |
| Culvert |
A covered channel or pipe designed to prevent the obstruction of a watercourse or drainage path by an artificial construction |
| Fluvial flooding |
Flooding resulting from water levels exceeding the bank level of a river or stream |
| Groundwater flooding |
Occurs when water levels in the ground rise above the natural surface. Low lying areas underlain by permeable strata (e.g. Chalk) are particularly susceptible |
| Main river |
All watercourses shown as such on the statutory main river maps held by the Environment Agency and the Department of Environment, Food and Rural Affairs for which the Environment Agency has responsibilities and powers |
| Ordinary watercourses |
All watercourses that are not designated Main River, and which are the responsibility of local authorities or Internal Drainage Boards (IDBs) |
| Resilience measures |
Measures designed to reduce the impact of water that enters property and businesses; could include measures such as raising electrical appliances |
| Resistance measures |
Measures designed to keep flood water out of properties and businesses; could include flood guards for example |
| Surface water/runoff |
Rainwater (including snow and other precipitation) which is on the surface of the ground (whether or not it is moving), and has not entered a watercourse, drainage system or public sewer. The term 'surface water' is used generically to refer to water on the surface |
