As we announced in our previous blog, regulations for sustainable drainage systems (SuDS) for new property developments in Wales come into force today (7th January 2019).
The National Assembly passed the Sustainable Drainage (Enforcement) (Wales) Order 2018 and The Sustainable Drainage (Appeals) (Wales) Regulations 2018 on the 13th November 2018.
As part of the regulations, “SuDS Approving Bodies” (SABs) will be set up within every local authority to approve drainage plans. The SAB or local planning authorities will have powers to issue enforcement notices to a developer who breaches the requirements. Developers will have a right of appeal to the Welsh government against the decision of a SAB.
The new mandatory requirements prohibit the commencement of any construction work which has drainage implications until a SuDS system has been approved by a SuDS Approval Body (“a SAB”). All new developments of more than 1 house or where the construction area is 100m2 or more will require sustainable drainage systems (SuDS) for managing surface water.
Welsh SuDS guidance is more wide ranging than England and includes additional criteria that must be assessed by the developer and signed off by the SAB. The relevant standards are as follows:
S1. Surface water run off destination
S2. Surface water run off hydraulic control
S3. Water Quality
S6. Design of drainage for construction, operation and maintenance
Standard S1 refers to a drainage hierarchy, prioritising the choice of run off destination, early consideration is given to the use of rainwater harvesting systems. Where this is not practical, prioritisation should be given to infiltration. Discharges to sewerage systems should be limited where possible.
The other standards state the minimum design criteria for SuDS and how they should be constructed, maintained and operated. Developers should demonstrate compliance with these standards in submitting planning applications. Local guidance will also need to be considered.
Around 163,000 properties in Wales are at risk of surface water flooding and employing sustainable drainage systems is estimated to reduce flood damage by up to 30 per cent, according to a 2017 Welsh Government Report.
SuDS work by making use of landscape and natural vegetation to control the flow of surface water and reduce the risk of flooding. Designs can include ponds, permeable paving and swales, which slow down the discharge of surface water more than conventional piped drainage.
Surface runoff water can also be a source of pollution, both directly and from sewers discharging into rivers. SuDS are designed to reduce surface water runoff and improve water quality while being more resilient and longer lasting than conventional drainage.
The Welsh government launched a consultation on draft regulations for the implementation of Suds on new developments in November 2017. Previously voluntary, the new mandatory rules aim to combat the challenges faced by climate change. Indeed, just last October there was severe flooding in Camarthenshire from Storm Callum.
Pollution and damage to the environment from surface water flooding is estimated to cost the Welsh economy around £60 million to £130 million per year.
To meet this new legislative challenge, architects, planning consultants and developers must ensure they get the fullest possible site appraisal on drainage conditions and suitability for SuDS measures.
Geosmart can provide a SuDSmart Pro report available for sites in Wales which incorporates the new mandatory requirements in all of our drainage strategies and has been designed to ensure efficient approval from the SAB.
The report provides an initial view on site infiltration capability for surface water drainage, more detailed run off calculations and preliminary SuDS design that can be used as part of the pre-planning engagement process with the relevant Local Planning Authority.
Contact us today on 01743 298100 or email us at email@example.com to gain an insight into the Welsh SuDS requirements and if you have any projects you require assistance with.