Page 26 - Merton SuDS DESIGN & EVALUATION
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6.0 Local SuDS requirements for
Local SuDS requirements
Merton
Landscape Character flows north through the centre of the
Borough and its main tributary, the River
The London Borough of Merton is located in Graveney, forms the Borough’s eastern
the south west of Greater London and covers boundary.
an area of approximately 37km2. The main
urban centres within Merton are Wimbledon, Geology
Raynes Park, Colliers Wood, Morden and
Mitcham, which are comprised of mostly The underlying bedrock of Merton is almost
commercial and residential land uses. entirely London Clay, with a small area of
Claygate Member and Bagshot Formation to
The majority of the Borough is low lying the northwest. The majority of the superficial
except the area in the north west, namely deposits are various River Terrace Deposits
Wimbledon and Wimbledon Common, where (gravel, sandy and clayey in part), which
elevations reach 55m above Ordnance differentiate on the basis of altitude but are
Datum. The rest of London Borough of geologically similar. These can be sub-divided
Merton is lower lying at 18-35mAOD, with into Taplow Gravel Formation and Hackney
gentle slopes associated with the floodplains Gravel Member which are located in the
of the River Wandle and Beverley Brook Mitcham area; Kempton Park Grave in Merton
21 catchments. and New Malden and Black Park Gravel is
located on the higher ground at Wimbledon.
The Borough is generally urbanised and has
large areas of impermeable surface, with the Ribbons of Alluvium (mainly sand, silt and
clay) are distributed along the River Wandle
main town centres interspersed by large
areas of green open space, namely and Beverley Brook.
Wimbledon Park, Wimbledon Common, Ground investigations have shown a shallow
Bushey Mead, Morden Park, Morden Hall Park perched groundwater layer is common across
and Mitcham Common. significant parts of the borough, due to the
presence of the underlying London Clay. This
The Borough contains four main river
watercourses; Beverley Brook, Pyl Brook, perched groundwater layer can result in
groundwater ingress to basements if tanking
River Wandle and River Graveney. The
Beverley Brook forms the western boundary is not appropriate or up to standard.
of the London Borough Local Drainage and Sewer Network
of Merton and its main tributary, the Pyl The waste water drainage infrastructure
Brook flows northwest through the southwest across the borough is generally a separate
corner of the Borough. The River Wandle surface and foul sewer system which is the
London Borough of Merton SuDS D & E Guide © 2018 McCloy Consulting & Robert Bray Associates
