Page 93 - Lewisham SuDS DESIGN & EVALUATION
        P. 93
     Detailed Design
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                                                             Designers should provide the following:
                                                                ■  the net increase in impermeable area
                                                                ■  greenfield runoff rates are calculated
                                                                based on the area of the redevelopment
                                                                parcel and not the wider development
                                                                ■  storage requirements for additional
                                                                impermeable area based on outflow
                                                                controlled to greenfield rates for the
      Facing: The Islington, Ashby Grove Raingarden.
      A raingarden for a single property with control           development parcel.
      tube and overflow that can manage the 1 in 100
      year return period rainfall event.
      Lewisham Council SuDS D & E Guide                                                                       © 2018 McCloy Consulting & Robert Bray Associates





