Guidance for architects, and developers on flood risk, drainage and phase 1 contaminated land reports is summarised below with links to the key summary documents.
The developer and their environmental consultant, such as GeoSmart, will need to assess the potential risks from contamination on the basis of the proposed use and local circumstances. This should normally be done before the formal planning permission is given for the development. However, in some cases, permission can be granted subject to a condition, which will require developers to investigate whether there is any land contamination and, if necessary, devise a strategy to deal with it.
Where a developer is proposing to develop land that is suspected of being contaminated, it is advisable to contact the Contaminated Land Officer before submitting the planning application. It is useful to do this as the Council may have additional information that you are unaware of, and may also be able to answer any particular questions that you have.
Procedure for dealing with land potentially affected by contamination:
Camden Council request a site walkover is undertaken as part of the desktop study.
There have been two major flooding incidents recorded in recent history in Camden, taking place in 1975 and 2002. The 1975 flood was caused by a severe storm in August 1975. It caused extensive flooding in West and South Hampstead as well as Gospel Oak, Kentish Town, Belsize Park and Camden Town. It was the heaviest and most concentrated rainfall event since records began for this part of Camden, with 150mm falling in two and a half hours. The drainage capacity of drain pipes, road gullies and sewers was unable to cope with the volume of surface water runoff involved.
The resultant flooding in August 2002 inflicted considerable damage on Camden residents and their homes, public services and facilities, and private businesses. Nearly all the flooding occurred north of the Euston Road, and primarily in West and South Hampstead (NW2 and NW6 postcode areas), although there was also flooding in parts of the NW3 postcode area, in Kentish Town (NW1 and NW5), and on a few other roads elsewhere.
Camden is not at risk from flooding from the sea or rivers. It is primarily at risk from surface water runoff (i.e. rainwater that is on the surface of the ground and has not entered a watercourse, drainage system or public sewer), groundwater or flooding from sewers which have been filled beyond capacity due to heavy rainfall.
The NPPF states that a site specific FRA is required in the following circumstances:
It should be noted that LBC is located entirely within Flood Zone 1 and therefore no proposals located within Flood Zone 2 and 3 will be brought forward for development.
Developments in areas which have been identified as being at risk of surface water flooding must be designed to cope with storm events with a 1% chance of happening in any one year/ 1 in 100 year return period (including an appropriate allowance for climate change). This is in order to limit the flooding of, and damage to, property.
It is essential that the type of Sustainable Drainage System (SuDS) for a site, along with details of its extent and position, is identified within the planning application to clearly demonstrate that the proposed SuDS can be accommodated within the development.
Within Camden, SuDS systems must be designed in accordance with London Plan policy 5.13. This requires that developments should utilise sustainable urban drainage systems (SUDS) unless there are practical reasons for not doing so, and should aim to achieve greenfield run-off rates and ensure that surface water run-off is managed as close to its source as possible in line with the drainage hierarchy.
Applicants are strongly advised to discuss their proposals with the Lead Local Flood Authority at the pre-application stage to ensure that an acceptable SuDS scheme is submitted.
Camden have pro-forma that accompanies their advice note on surface water drainage. Developers should complete this form and submit it to the Local Planning Authority, referencing from where in their submission documents this information is taken. GeoSmart can assist in producing a drainage strategy that will help complete this pro-forma.
Camden has a small risk of groundwater flooding which occurs when the water table rises to ground level and inundates low lying areas. There are a small number of recorded incidents of groundwater flooding in basements and cellars.