Flooding and flood risk

What is flooding?

Flooding is a natural process that occurs when water exceeds normal levels and the land’s ability to drain that water into its usual channels. Flooding is related to ‘catchment areas’ and is affected by factors beyond the Borough boundary.

The intensity and frequency of flooding is expected to increase as a consequence of climate change. You can find out more in the council’s Climate Change and Carbon Management strategy.

The council cannot stop all flooding but it has a duty to work with partners, including the Environment Agency, to:

  • manage flood risk from all sources
  • reduce the consequence of flooding on human health, economic activity, cultural heritage and the environment.

It does this by meeting its statutory duties, including preparing the plans described below.

Slough experiences flooding from a range of sources:

  • River flooding (fluvial) occurs when a watercourse cannot cope with the water draining into it from the surrounding land. This can happen, for example, when heavy rain falls on already waterlogged land. The fluvial flood maps for Slough are updated every 6 months and are available from the Environment Agency. You can find out if your area is at risk from fluvial flooding from main watercourses from the Environment Agency website
  • Surface water flooding occurs when heavy rainfall overwhelms the drainage capacity of the local area. It is more difficult to predict and pinpoint than river flooding
  • Sewer flooding occurs when sewers are overwhelmed by heavy rainfall or when they become blocked and overflow
  • Groundwater flooding occurs when water levels in the ground rise above surface levels.