Policy information sourced from Hammersmith & Fulham Local Plan
CC4 MINIMISING SURFACE WATER RUN-OFF WITH SUSTAINABLE DRAINAGE SYSTEMS
All proposals for new development must manage surface water run-off as close to its source as possible and on the surface where practicable, in line with the London Plan drainage hierarchy. Other requirements include:
- all major developments must implement Sustainable Drainage Systems (SuDS) to enable a reduction in peak run-off to greenfield run off rates for storms up to the 1 in 100 year event (plus climate change allowance);
- all major developments will be required to provide a sustainable drainage strategy that demonstrates how SuDS will be integrated to reduce peak flow volumes and rates in line with the requirements of this policy;
- all other developments must maximise attenuation levels, achieving greenfield run off rates where possible, particularly where they are located in surface water flooding hotspots, or increase a site’s impermeable area;
- as well as being designed to minimise flood risk, surface water drainage measures must be designed and implemented where possible to help deliver other Local Plan policies such as those on biodiversity, amenity and recreation, water efficiency and quality and safe environments for pedestrians and cyclists;
- all new outdoor car parking areas and other hard standing surfaces shall be designed to be rainwater permeable with no run-off being directed into the sewer system, unless there are practical reasons for not doing so;
- all flat roofs in new developments should be living roofs to help contribute to reducing surface water run-off; and
- where installed, SuDS measures must be retained and maintained for the lifetime of the development and details of their planned maintenance must be provided to the council.
For more information please see the Local Plan