All local planning authorities are required to prepare a Strategic Flood Risk Assessment (SFRA) for their areas. SFRA aims to assess the risk of flooding from all sources and is the basis for applying the ‘sequential’ and exceptions tests to potential development sites identified for inclusion in the Local Plan.

We procured consultants to prepare an SFRA in September 2014. This was jointly for each of the partner Boroughs located within the River Wandle catchment:

  • Sutton
  • Croydon
  • Merton, and
  • Wandsworth

The SFRA Level 1 Report

You can read the full SFRA Level 1 (December 2015) report:

The SFRA Level 1 Report shows:

Areas at risk from fluvial (river) flooding falling

  • EA Flood Zone 1 (low risk)
  • Flood Zone 2 (medium risk)
  • Flood Zone 3a (high risk) and
  • Flood Zone 3b (functional floodplain)

This is based on updated EA modeling for the River Wandle, Beverley Brook, and Pyl Brook.

Areas at high, medium, low, and very low risk of surface water flooding based

This is based on the EA’s updated flood map for surface water (uFMfSW).

Catchments, hotspots, and groundwater

  • surface water drainage ‘catchments’ and hotspots
  • areas susceptible to groundwater flooding and areas that have experienced sewer flooding

The Level 1 Report contains planning policy recommendations and a site assessment database. This is to undertake the sequential test on potential development sites. The findings of the sequential test are set out in the Sustainability Appraisal (SA) Report (Google Drive) on Sutton’s draft Local Plan which has been published for public consultation between 9 January and 24 February 2017.

SFRA Level 2 Report

Sutton’s amended SFRA Level 2 Report (March 2017) provides technical information and guidance on proposed site allocations located within flood risk areas to show:

  • how they could be developed in line with the Government’s ‘Exception Test’, and
  • ensure that “the development will be safe for its lifetime taking into account the vulnerability of its users and that it won’t increase flood risk elsewhere”

The SFRA level 2 Report forms an important part of Sutton’s Local Plan evidence base It should be used to inform the preparation of site-specific flood risk assessments (FRAs) by developers.

View our SFRA Level 2 report (Google Drive)