Page 117 - Hillingdon SuDS DESIGN & EVALUATION

9.9.3 Key design criteria for biodiversity in the developed landscape

9.9.3.1 Clean water

Clean water is critical as soon as possible for Connectivity is inherent in the management
all open water features in the landscape. train principle but must be considered Detailed Design
Clean water is delivered using initial pollution carefully where one feature links to the next.
prevention measures to prevent Surface conveyance and overflow routes,
contaminants reaching water, source control with a minimum use of pipework and
features and further site controls along the inspection chambers, is helpful in retaining
management train. wildlife links.

There should be a direct connection between
the SuDS landscape and the blue/green
9.9.3.2 Structural diversity
infrastructure that receives the ‘controlled
Structural diversity both horizontally and flow of clean water’ from the development.
vertically within water features, the landscape
and in vegetation generally provides habitat
variety for wildlife. Structural diversity is 9.9.3.4 Prevent pollution to habitat
inherent in many SuDS features particularly
Permanent vegetation should cover all soil
swales, basins, wetlands and ponds that can
surfaces to prevent silt runoff and planting
easily be enhanced for habitat creation.
should be designed to avoid the use of
Ornamental planting should mimic natural fertilizer, pesticides and herbicides.
vegetation by developing a complex vertical 112
structure of trees, shrubs and herbaceous

cover. 9.9.3.5 Maintenance for wildlife

Sympathetic maintenance enhances
biodiversity but should be compatible with
9.9.3.3 Connectivity
the aspirations of the local community to
Connectivity between wetland habitat areas ensure acceptance of a more natural
both within and outside the site encourages landscape character.
colonisation into and throughout the
development landscape. These connections
are particularly important both for animals on
the ground but animals like bats use
individual trees and woodland edges to travel

from one place to the next and use SuDS
wetlands to feed.

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