Page 73 - Hillingdon SuDS DESIGN & EVALUATION

9.1 Objectives of Detailed Design

Detailed Design should develop and refine ■ meet the requirements for NPPF and

the agreed SuDS strategy from the Concept NSTS along with Local SuDS Standards
and Outline design stages. Outputs from the and SuDS related planning policies
detailed design should: Detailed Design
■ confirm how the SuDS scheme maximises
■ provide sufficient information to give the opportunities for amenity and biodiversity
LPA and LLFA a full understanding of how ■
the scheme will appear and operate deliver schemes which are legible and
function passively.

9.2 What Detailed Design should demonstrate

The SuDS Detailed Design considers in detail ■ proportionate analysis to confirm
all the influencing factors on the scheme with attenuation volumes with allowances for
over-arching requirements as follows: climate change and urban creep, and
controlled flow rates for each sub-
■ the use of Source Control techniques
provides a controlled flow of clean water catchment and final site discharge rates
through the site ■ materials and plant varieties specified
accord with local landscape character
■ demonstrate that the modified flow

route(s) provides for extreme flows and ■ demonstrate safe design for contractors, 68
where possible connectivity corridors for operatives and general users of the site
biodiversity through the site
■ that SuDS which are being offered for
■ carefully consider all site levels to ensure adoption meet the relevant standards of
that the system will function as intended the adopting body.
in ‘day to day’ and also extreme
conditions

■ demonstrate that individual SuDS
components meet respective design
criteria

Design Note :

Schemes invariably evolve and change from concept stage. The designer should therefore
confirm no material changes to drainage strategy from that agreed with LPA at the Concept
or Outline design stages. Any materials changes should be discussed and agreed with the
LPA prior to detailed design submission.

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