Policy information sourced from Hammersmith & Fulham Local Plan
CC3 MINIMISING FLOOD RISK AND REDUCING WATER USE
The council will require developments to reduce the use of water and minimise current and future flood risk by implementing the following measures:
- a site specific Flood Risk Assessment (FRA) will be required for the following development proposals:
- all proposals for developments in the Environment Agency’s Flood Zones 2 and 3;
- all proposals for new developments over 1 hectare in size in Flood Zone 1;
- all proposals for new development in areas identified in the council’s Surface Water Management Plan (SWMP) as being susceptible to surface water flooding – i.e. those located in a flooding hotspot; and
- all proposals for new development which includes a subterranean element in areas identified in the council’s SWMP as being at risk from elevated groundwater levels
- as part of the FRA, the requirements of the National Planning Policy Framework must be addressed and, where applicable, an Exception Test must also be carried out and included in the FRA;
- the FRA must assess the risk of flooding from all relevant sources, in particular tidal, surface and groundwater, as well as sewer flooding and where there is a risk of flooding, appropriate flood proofing measures must be integrated, in accordance with the guidance in the Hammersmith and Fulham SFRA;
- new self-contained basement flats will not be permitted in the Environment Agency’s Flood Zone 3 areas where there is a risk of rapid inundation by floodwaters in the event of a breach of the river’s flood defences or in surface water flooding hotspots where the flood hazard rating is defined as significant or higher in the SWMP, unless a satisfactory means of escape can be provided;
- where development is proposed in the Environment Agency’s Groundwater Source Protection Zones 1 or 2, measures must be taken to ensure the protection of groundwater supplies;
- all developments that include a subterranean element must provide details of the structural waterproofing measures to be integrated to prevent any increase in on or off-site groundwater flood risk;
- all developments that are classified as ‘more’ or ‘highly’ vulnerable to flooding that include proposals at basement or lower ground floor level must install a non-return valve or equivalent to protect against sewer flooding;
- development proposals will be required to demonstrate that there is sufficient water and waste water infrastructure capacity both on and off site to serve the development or that any necessary upgrades will be delivered ahead of the occupation of development;
- in line with the requirements of the Thames Estuary 2100 Plan, developments adjoining the River Thames must maintain and where necessary enhance or raise flood defences (or show how they could be raised in the future), demonstrating that they will continue to provide adequate flood protection for the lifetime of the development; and
- all developments must include water efficient fittings and appliances, where provided, in line with London Plan water consumption targets. In addition, major developments and high water use developments must include other measures such as rainwater harvesting and greywater re-use.
For more information please see the Local Plan