Page 122 - Oxfordshire SuDS DESIGN & EVALUATION

Detailed Design SuDS grass

SuDS grass describes the longer amenity
grass used wherever water is likely to move
or flow, even minimally.

It is ideal for the immediate protection of any
flow areas.

Eventually this turf can be colonized by
wildflowers adapted to regular cutting but in
the first instance an amenity grass mix is
often used as seeding or turf to cover the
surface of SuDS components before water
flows across the surface. Suppliers tend to
offer standard species mixes although
specific mixes can be purpose grown where
there is a lead in time of 10 or more weeks in
the growing season.

■ The grass is long enough to act as a filter
but short enough to prevent ‘lodging’
(lying flat under flow conditions) and so
Longer SuDS grass as a filter strip between
must be maintained between 75mm and paved surfaces and a raingarden.
117 150mm in height.

■ Turf can be laid in spring and autumn or
when weather conditions are suitable, for
instance in mild spells in winter or wet
weather in summer. Pegging the turf may
be necessary, with fully biodegradable
pegs, to prevent water flow lifting the
turves.

■ In dry weather a coir or jute mesh
covering a seeded surface can be used to
establish grass but there may be bare

patches to repair in the autumn. Facing: A seeded meadow in a ‘playful
raingarden’ at Renfrew Close Community
Raingardens, Newham.

Design Note:
This is best specified as turf as it is functional as soon as it is laid.

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