Sustainable urban drainage systems (SUDS) have been part of building and development design and planning for a while now, but there is still some confusion about what SUDS mean in practice.
Put simply, SUDS are a natural approach to managing drainage in and around properties and other developments. Rather than routeing run-off to a water course via piping, SUDS mimic natural, non-urbanised draining systems. SUDS control surface water run-off close to where it falls. Benefits include:
- Reduction in flooding
- Removal of pollutants at source
- Improvement of water quality
- Enhanced amenity and biodiversity value of environment
How do SUDS work?
SUDS work by:
- Slowing and holding back the water that runs off from a site
- Settling and filtering sediment from run-off
- Allowing natural processes to break down pollutants
- Lowering flow rates
- Increasing water storage capacity
SUDS techniques include:
- Green roofs
- Permeable surfaces
- Infiltration trenches, filter drains and filter strips
- Detention basins, purpose built ponds and wetlands
SUDS are now a must
While forward thinking planners have been making SUDS part of the planning process of new developments for some years now, not everyone has been keen to incorporate this form of drainage system.
The situation has now changed as SUDS are no longer an optional extra to builders and developers. The Flood & Water Management Act 2010 began the process of restricting developers’ rights to connect new houses directly to existing drainage systems and compelling them to integrate SUDS into new building.
Then, from April 2015, local planning policy and decisions on Major Developments (10 dwellings or more; or equivalent non-residential or mixed development) were expected to ensure that sustainable drainage systems were put in place, unless demonstrated to be inappropriate.
What’s holding SUDS back?
It’s clear that SUDS make sense for the environment and the wider public. Increasing strain on flood defences in recent years and the increasing need to protect and ensure safe water supplies are vital.
So why has implementation of SUDS been slow in England?
Adoption and maintenance responsibility
One of the obstacles to implementation has been adoption and maintenance. The different parties involved, including developers, adopting bodies and regulatory authorities need to work together to establish clear accountability of ownership and maintenance responsibilities at the outset.
Start at the beginning
Too often, SUDS are looked at when the planning and development planning is already quite far advanced. SUDS need to be considered at the beginning of the project. Trying to add them to an existing plan can be problematic and expensive. Incorporating them into first-stage planning is much more effective, in terms of both cost and practicalities.
SUDS are now set to be an integral part of building and development. Ignoring this fact could create problems and expense in the longer term. On the other hand, those developers that show a proactive, organised and creative approach to SUDS will win out. Forward planning that includes SUDS will not only create efficiencies within the building process but could become an essential part of winning contracts and building business.