Policy information sourced from The Waltham Forest Blackhorse Lane Area Action Plan

BHL11 Flood Risk

A) New developments in Blackhorse Lane should be designed and sited to minimise and reduce flood risk to new and existing communities.

B) Basement dwellings will not be permitted, in the interests of avoiding groundwater flooding issues.

C) All sites in flood zones 2 or 3, and any other sites over 1 hectare, should be accompanied by a site specific flood risk assessment. This should be used to ensure new developments minimise risk through matters such as:

  1. ncorporating Sustainable Urban Drainage Systems (SuDs) to achieve Greenfield run-off rates, including maintenance schemes to ensure their long term effectiveness is not compromised;
  2. configuring road and building layouts to preserve and improve existing flood routing;
  3. raising habitable floor levels to an appropriate height above the maximum flood water level;
  4. using flood resistant or resilient construction techniques dependent on likely depth of flooding;
  5. providing safe routes to and from properties, and evacuation strategies, so that site users and residents have a means of safe access and egress during times of flood

D) Where any development is proposed in areas susceptible to a 1 in 100 year flood event, taking account of climate change (as shown in figure 17), provision should be made for an equal level of compensation storage in the local area to mitigate for this loss. This compensation must be level for level and volume for volume and not alter flooding mechanisms or increase flood risk offsite. Compensation must also be able to account for climate change.

E) Only water compatible and essential infrastructure uses (as defined by national policy and associated technical guidance), will be allowed in flood zone 3b.

F) Where development is proposed near the Dagenham Brook:

  1. No new development should be built over the Dagenham Brook Culvert;
  2. All development should be set back at least 4 metres from the edges of the culvert and 8m from the open sections of the Dagenham Brook;
  3. Opportunities should be investigated to open up the culvert and naturalise the banks of the watercourse and implemented where possible.

For more information please see the Area Action Plan