Flood Risk

SPP7

 

The central purpose of Scottish Planning Policy 7: Planning and Flooding is to prevent further development which would have significant probability of being affected by flooding or which would increase probability of flooding elsewhere.  For coastal and watercourse flooding a Risk Framework characterises areas for planning purposes by their annual probability of flooding and gives the planning response as follows:

  • Little on no risk area (less than 0.1% (1:1000)) - no general constraints.

  • Low to medium risk area (0..1% to 0.5% (1:1000 - 1:200)) - suitable for most development but not essential civil infrastructure.

  • Medium to high risk area (0.1% (1:200)) or greater - in built up areas with flood prevention measures most brownfield development should be acceptable except for essential civil infrastructure; undeveloped and sparsely developed areas are generally not suited for most developments.

Flood risk is a material planning consideration for a wide range of sites including those with a history of flooding, in a flood plain, on low lying coastal land, adjacent to a watercourse, drained by a culvert, with drainage constraints or otherwise poorly drained.  If flooding is an issue a Flood Risk Assessment Report will be required.  Planning authorities have powers under the Town and Country Planning (General Development Procedure) (Scotland) Order 1992 (GDPO) to require additional information and evidence, including flood risk assessments, for outline as well as full applications.  An FRA will need to include the technical means of reducing the risk of flood damage to an acceptable level and should include the following:

  • Relationship of site levels to potential flood levels (AOD)

  • Historical data research on past flooding incidents

  • Obtaining data from the LPA and SEPA

  • Calculating 1 in 200 flood levels

  • Flood modelling using MIKE FLOOD as appropriate

  • Assessing existing flood defences (Breach assessment if required)

  • Recommending development solutions