Policy information sourced from the Islington Local Plan

S6 Managing heat risk

  • A site specific Flood Risk Assessment (FRA) will be required for:
    1. proposals on sites of 1 hectare or greater;
    2. new development proposing more than 100sqm increase in floorspace in a critical drainage area;
    3. proposals involving a change of use in development type to a more vulnerable class;
    4. ‘Highly Vulnerable’ development located in an area of High or Medium surface water flood risk; and/or
    5. ‘More Vulnerable’ development located in an area of High surface water flood risk.
  • The site-specific FRA must assess in detail the risk of flooding to and from a proposed development, from all sources but focusing particularly on surface water flooding, taking climate change projections into account. Where a development is located within a Critical Drainage Area (CDA) or Local Flood Risk Zone (LFRZ), or where the site includes a ‘High’ surface water flood risk area, the site-specific FRA must give particular consideration to the extent and impacts of flood risk.
  • Groundwater flooding must be investigated in detail as part of the site-specific FRA where development is located in an area identified as having potential for groundwater flooding.
  • As part of the site-specific FRA, development proposals must:
    1. carry out a Sequential Test in order to ensure that the vulnerability classification of the proposed development is appropriate to the level of flood risk;
    2. carry out an Exception Test (parts a and b) to ensure the proposed development will provide wider sustainability benefits to the community that outweigh flood risk, and that it will be safe for its lifetime, without increasing flood risk elsewhere and where possible reduce flood risk overall; and
    3. demonstrate a sequential approach to development layout within the development site, in order to ensure that the most vulnerable elements or land uses within a development are located in the lowest risk parts of the site.
  • The site-specific FRA must demonstrate how flood risk will be managed and mitigated to ensure the development is safe from flooding and the impacts of climate change for its lifetime. This must include assessment of appropriate flood proof design and construction methods, and SUDS.
  • ‘Highly Vulnerable’ development, including basement dwellings, proposed in ‘High’ surface water flood risk areas, and/or where there is potential for groundwater flooding of property situated below ground level or potential for groundwater flooding to occur at surface, are required to incorporate appropriate flood proof construction methods in order to mitigate the risk of flooding. Essential infrastructure associated with proposed developments in ‘High’ surface water flood risk areas must be located above ground floor level, where possible.

For more information please see the Islington Local Plan