This document provides a list of "DON'Ts" for planning and designing sustainable urban drainage systems (SUDS). The DON'Ts include not using existing ponds or wetlands for SUDS treatment, not using attenuation tanks for water quality treatment, and not allowing construction phase run-off to enter SUDS unless temporary treatment systems are provided. The document also lists corresponding "DOs" such as using source control techniques, minimizing impermeable areas, and designing SUDS for wildlife and amenity.

1. SUDSDON’T
DON’Ts
DON’T use existing ponds, wetlands or ditches for
A DOs and DON’Ts GUIDE
for PLANNING and DESIGNING
SUDS treatment.
DON’T use attenuation tanks for water quality treatment. Sustainable Urban
DON’T install end-of-pipe filter drains/infiltration
trenches, swales or soakaways for 5 houses, unless
additional SUDS treatment is provided upstream.
Drainage Systems (SUDS)
DON’T design filter drains/infiltration trenches with a
bypass at the inlet.
DON’T insert inlet pipes at the base of filter
drains/infiltration trenches - insert at high level.
DON’T use filter drains/infiltration trenches where the
water table is shallow
DON’T incorporate gulley pots in permeable paved areas.
Further information
DON’T allow construction phase run-off to enter SUDS Please contact your local SEPA office for further information
unless it is intended that the SUDS will be replaced or or visit the following websites:
restored. Temporary treatment systems separate to the
www.sepa.org.uk/wfd
SUDS should normally be provided.
www.ciria.org.uk/suds
DON’T use infiltration based SUDS for industrial estate
drainage unless a groundwater risk assessment (prior
investigation) has been undertaken and shown to be 1 ‘Sustainable Urban Drainage Systems – Design Manual for Scotland and
acceptable. Northern Ireland’ (CIRIA Report C521) and its successor ‘The SUDS
Manual’ (CIRIA Report C697 - to be published).
DON’T use infiltration based SUDS on contaminated land, 2 ‘Sewers for Scotland 2nd Edition – a Policy, Designed Construction
unless the system is impermeably lined. Guide for Developers in Scotland’ (WRC - to be published).
DON’T drain run-off from ‘high risk areas’ to the surface
3 The Water Environment (Controlled Activities) (Scotland) Regulations
2005 Schedule 3 ‘General Binding Rules’ (Activities 10 11) and
water drainage system (e.g. oil, chemical and waste associated guidance.
storage areas, delivery and refuelling areas, industrial
yards, wash areas etc).
For developers, landowners, planners,
consultants, architects and engineers

2. SUDS
Who is this leaflet for?
This leaflet is aimed at anyone involved in the planning or
design of SUDS schemes. This includes developers, landowners,
planners, consultants, architects and engineers.
What are SUDS?
SUDS mimic natural systems for draining surface water and
include porous surfaces, soakaways, infiltration trenches, filter
drains, filter strips, swales, detention basins and purpose built
ponds and wetlands. As well as treating polluted surface water
What is it for? runoff, SUDS provide attenuation of surface water to reduce
This leaflet provides a quick checklist of DOs and DON’Ts to the impact of flow on watercourses. Well designed SUDS can
consider when planning and designing SUDS. This leaflet make a positive contribution to the amenity and wildlife value
should be read in conjunction with the main reference sources of a site.
for the design of SUDS1, 2 and is not intended to replace these
more detailed documents. Legal Requirements
The main legislation covering the regulation of surface water
discharges is the Water Environment (Controlled Activities)
(Scotland) Regulations 2005. Through SEPA’s implementation
of these regulations, certain categories of surface water
DOs General DOs Specific discharge automatically require an application for a licence.
For example, housing developments 1,000 houses, 1,000
DO allow sufficient landtake for SUDS when planning the DO use porous surfacing for driveways and parking areas car park spaces, industrial estates and motorways.
site layout (typically 5-7% of the site area but can be or allow run-off to shed to adjacent land. All other discharges of surface water, as a minimum, require to
DO
significantly less if source control techniques are used). DO use sheet flow to direct water into infiltration comply with the General Binding Rules (GBRs) for surface
DO use a surface water management train. trenches, filter drains, filter strips and swales rather than water discharges which specify a requirement to provide SUDS
DO use source control, even when regional facilities gulleys and pipes. or equivalent (with an exemption for single dwellings and
are provided DO use slotted pipes for filter drains in preference to discharges to coastal waters3). If in doubt as to whether or not
flexible perforated pipes. a licence is required, contact your local SEPA office.
DO minimise impermeable areas and encourage as much
infiltration as possible (except for certain industrial estate DO use unsealed disconnecting manholes with porous Inappropriately or wrongly designed SUDS found to be causing
drainage and on contaminated land – see list of DON’Ts). base and walls where suitable. pollution, or pollution arising during the construction phase of
development, may result in SEPA taking enforcement action
DO avoid pipes where possible - use swales or DO use water butts to attenuate roof drainage.
including a requirement to carry out remedial work and/or
open ditches. DO allow access for maintenance (e.g. for referral to the Procurator Fiscal for prosecution.
DO attenuate run-off to pre-development values. mowing swales).
DO produce a maintenance schedule and ensure that a DO use silt traps upstream of SUDS where appropriate.
nominated person/body is clearly responsible. DO prepare a method statement detailing the pollution
DO design SUDS for wildlife and amenity (e.g. by prevention measures to be used during the construction
providing ponds and wetlands). phase of any development.
DO provide site operators/new householders with written DO ensure inlet and outlet structures are adequately
information on the SUDS system you have provided and designed to prevent erosion within the SUDS.
how it works. DO check for wrong connections during construction and
on completion of the development.