There are three types of flooding, which could occur in Northamptonshire, fluvial, flash and groundwater.
Fluvial flooding can affect those living in close proximity to brooks, streams, rivers and lakes etc. Fluvial flooding occurs when the water features cannot cope with the amount of water draining into them, from the land. In winter months this is usually because the ground has become saturated and can no longer absorb water properly. When rainfall is heavy and/or prolonged, large amounts of run-off reaches the rivers and eventually causes them to overtop their banks.
People, who do not live in close proximity to water features, can still be flooded by Flash flooding. Flash flooding can happen anywhere at any time, although it is more likely to happen in summer or winter months when the ground is hard and dry or saturated from previous storms. When sudden downpours occur such as those associated with thunderstorms, the rain cannot be absorbed into the ground. The water is then forced to run off into drains. ditches and culverts, which cannot cope with the volume. This effect then causes the rain to pool and in severe cases flood.
Groundwater flooding is rare and this only occurs when the underground water table rises to an unusually high level. This typically occurs after prolonged rainfall, ie during an unusually wet autumn and winter. As a result of the high rainfall the water table rises above its normal level. This effect causes springs and wells that have been dry for many years (eg 50 plus) to flow again. These springs and wells may cause nearby properties to flood.
Back to 'Guide to Flooding'