Page 100 - Hillingdon SuDS DESIGN & EVALUATION

Detailed Design 9.6.2 Distributed storage components the first component.

This approach is useful for exploiting small
parcels of available space within the
This can protect the functionality of
development and results in features, such as
downstream components as amenity spaces.
rain gardens and small basins which can be
The flow control opening for each
located close to buildings. These small
component can be easily calculated and
features are usually sized for between the 1 in
1 year and 1 in 10 year rainfall, with excess
passively move through subsequent storage
rainfall volumes conveyed along the
components without the requirement for
management train to site control. outflows from one storage component will
further storage.
This approach keeps subsequent storage
components from regular wetting as around Raingardens, such as this wildflower raingarden at
95% of rainfall events would be managed by St Paters School, Gloucestershire, are an excellent
example of the opportunities presented by
distributing storage throughout a development.

95

9.6.3 Single, uniform storage Permeable forming a plaza outside Bewdley

components School Science Block.

Permeable pavements and blue-green roofs
which have relatively flat formations can store
all rainfall events up to the 1 in 100 year within
their footprint. In this scenario the flow

control would be designed to ensure that the
depth of stored flow discharged at the
respective 1 in 1 and 1 in 100 year greenfield
runoff rates.

London Borough of Hillingdon SuDS D & E Guide © 2018 McCloy Consulting & Robert Bray Associates