Flooding & flood risk

An update report on flood management was presented to Cabinet in November 2013. The report included a recommendation to approve and adopt the Strategic Flood Risk Assessment 2012; the Surface Water Management Plan 2012; and the Local Flood Risk Management Strategy 2013. Details of these plans are provided below.

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, because for example they are at capacity. 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 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, and to 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 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.

Flood management plans

The Local Flood Risk Management Strategy (LFRMS) for Slough

The overarching objectives of the LFRMS are to improve safety, health and wellbeing for residents and create a cleaner/greener Slough. This will be done by for example by:

  • identifying where flooding occurs, and what it affects, and reducing flood risk where appropriate
  • avoiding inappropriate development in areas of flood risk
  • developing public awareness of flood risk
  • opening up watercourses where possible, improving public accessibility and enhance and improving their quality and biodiversity

Local Flood Risk Management Strategy for Slough.

Strategic Flood Risk Assessment (SFRA)

The SFRA identifies areas in Slough at risk from all sources of flooding, and sets out specific recommendations for future development within the different flood zones. It also identifies the level of detail required for site specific Flood Risk Assessments and surface water drainage schemes (see Core Strategy Policy 8) when planning applications propose development in areas of flood risk.

The SFRA is accopanied by a series of maps. The file sizes are too large to make available in detail online but the following are provided as a guide. Please note some of these files are still large so may take time to download. For more information on these please contact us

Draft Surface Water Management Plan (SWMP) (2012)

Outlines the preferred surface water management strategy for the Borough. Examines the causes and effects of surface water flooding and identifies most cost effective means of managing surface water flood risk for the long term.

Please note the maps and drawings supporting the SWMP are not available electronically due to their size, please contact us for more information.

Preliminary Flood Risk Assessment 2010

The PFRA identifies areas of Slough at significant risk of local flooding. In Slough, the Areas Susceptible to Surface Water Flooding mapping was considered to be the most applicable for Slough. A total of 8,758 residential properties were estimated at risk of surface water flooding in Slough.

The PRFA is available from the EA website.

Section 19 reports

Under the Flood and Water Management Act 2010 the Lead Local Flood Authority (Slough Borough Council) must, to the extent that it considers it necessary or appropriate, undertake an investigation upon becoming aware of a flood incident within its area. Section 19(1) requires that the Lead Local Flood Authority must investigate:

a) Which risk management authorities have relevant flood risk management functions, and

b) Whether each of those risk management authorities has exercised, or is proposing to exercise, those functions in response to the flood.

Section 19(2) requires that the Lead Local Flood Authority publishes the results of its investigation and notify the relevant risk management authorities accordingly. All Section 19 reports that have been produced by Slough Borough council are publically available below: