Combined Flood Risk Assessment & Detailed Surface & Foul Water Drainage Strategy
Civilistix Consulting Engineers were appointed to prepare a Flood Risk Assessment and Surface and Foul Water Drainage Strategy to support a planning application for creation of 2no. dwellings and 7no. flats and associated external hardstanding areas.
Due to infiltration being unviable and no watercourses within vicinity of the site in which to make a connection, we proposed all runoff from the proposed development make a controlled discharge to a public sewer.
Due to near the full site area consisting of building footprint, we proposed a basement attenuation tank with a controlled 5 l/s pumped discharge for all surface water.
To satisfy London plan stipulations and Local Westminster guidance, permeable paving was used for all external hardstanding areas and a green-roof used for a portion of the building roof area acting to slow down runoff and treat it prior to discharge.
We similarly proposed all foul water from development gravitate to a proposed pumping station located within the basement level providing sufficient emergency storage and blockage mitigation before being pumped to a small private high level drainage system connecting with the public sewerage network