Page 26 - Croydon
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6.0                                                                                                              Norbury Brook which feeds into the River               Flood Risk Areas in the Borough
                             Local SuDS requirements for
      Local SuDS requirements
                                                                                                                             Wandle further downstream. The south
                                                                                                                                                                                    The main areas of fluvial flood risk in the
                             Croydon
                                                                                                                             eastern part of the Borough, including the
                                                                                                                             settlements of Forestdale and Addington, is
                                                                                                                                                                                    Strategic Flood Risk Assessment (SFRA) and
                                                                                                                             characterised by steeper topography and                Borough, as illustrated in the Croydon
           Landscape Character                                                                                               more rural land which drains into the                  in the Local Flood Risk Management Strategy
                                                                                                                             tributaries of the River Ravensbourne which            (LFRMS), are located along Godstone Road
           The London Borough of Croydon is located in                                                                                                                              in Kenley and Purley (associated with the
                                                                                                                             flow north eastwards into the London
           the south of Greater London and covers an                                                                         Borough of Bromley.                                    Caterham Bourne), along Brighton Road                 Local SuDS requirements
           area of approximately 86km2.  It is bounded                                                                                                                              south of the Purley Cross roundabout and
           to the north by the London Boroughs of                                                                            Local Geology                                          around Wandle Park (associated with the
           Merton and Lambeth, to the east by the                                                                                                                                   culverted River Wandle), areas in the vicinity
                                                                                                                             The underlying bedrock of the London
           London Borough of Bromley, to the west by                                                                                                                                of the Norbury Brook along Thornton Heath
           the London Borough of Sutton and to the                                                                           Borough of Croydon is Middle and Upper                 and Norbury and areas in South Norwood
                                                                                                                             Chalk in the south, which is overlain by
           south by Tandridge District and Reigate and                                                                                                                              Country Park and Shirley (associated with
           Banstead Borough in Surrey. The Borough is                                                                        Thanet Sand Formation (fine sand), Lambeth             the Chaffinch Brook).
                                                                                                                             Group (clay and sand), Harwich Formation
           characterised by steep slopes in Coulsdon in
           the south which level off to flatter land in the                                                                  (sand and flint) and the London Clay Group             The main areas of surface water flooding are
                                                                                                                             in the north. The bedrock and drift geology in         located in Purley Town Centre, Purley Cross,
           north.  Brighton Road is located in the natural
           valley of the River Wandle, now entirely                                                                          the borough are illustrated in the map above.          Kenley Station, Brighton Road at Coulsdon,
                                                                                                                             Further information on the geology of the              Purley Oaks Road and Station, Norbury and
           culverted until it emerges at Wandle Park in
           South Croydon.                                                                                                    borough can be found in the British                    Thornton Heath. Additionally, during August
                                                                                                                             Geological Survey (BGS) website.                       2015 severe flooding also affected the areas
  21       The Borough is generally urbanised along the                                                                                                                             along Kenley, Coulsdon and New Addington.             22

           main transport corridors (A23, A232 and                                                                           Local Drainage and Sewer Network                       During June 2016, the area along Caterham
           railway) and in the north of the Borough, with
                                                                                               Geological Survey             The waste water drainage infrastructure in
           the main urban centres located in Central and
                                                                                               Solid                         the north of the Borough is generally a
           South Croydon, Thornton Heath and Purley.                                           Chalk-Middle                  separate surface and foul sewer system, with
           With increasing distance from the Croydon                                           Chalk- Upper                  combined sewer systems in small areas of
           Metropolitan Centre and the Brighton Road                                           Claygate Sand
                                                                                               Harwich Sand                  Upper Norwood and Waddon.  Thames
           corridor, development begins to open out                                            Lambeth Sand and Clay         Water is responsible for receiving surface
           with more park and rural land in the south of                                       London Clay                   water from developments in the north of the
           the Borough around Coulsdon and New                                                 Thanet Sand
                                                                                               Drift                         Borough which discharge via the adopted
           Addington.                                                                          Aluvium                       sewers.
                                                                                               Clay with Flints
           The Borough contains five main rivers; River                                        Hackney Gravel                In the south of the Borough there is no
           Wandle, Caterham Bourne, Merstham Bourne,                                           Head- Clay/Silt               surface water sewer system. The area is
           Norbury Brook and Chaffinch Brook. The                                              Head- Gravel
                                                                                               Kempton Park Gravel           generally served by soakaways with the
           majority of the Borough drains into the                                             Artifi cial Deposits          highway drained by a series of interlinked
           catchment of the River Wandle, which passes            Bedrock and drift
                                                                  geology (Source:                                           soakaways commonly referred to as “highway             Surface Water fl ooding in Caterham Drive,
           into the London Borough of Sutton. The                 London Borough of                                          drains”.                                               June 2016 (Source: Croydon Council - various
           northern part of the Borough drains into the           Croydon)                                                                                                          offi  cers)


           Croydon Council SuDS D & E Guide                                                                        © 2018 McCloy Consulting & Robert Bray Associates  Croydon Council SuDS D & E Guide                                                                         © 2018 McCloy Consulting & Robert Bray Associates
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