Notice: This blog piece was created prior to the formation of the British Precast Drainage Association.

Posted by & filed under SuDS, Sustainability.

In November I wrote about industry concerns with the Government’s proposed approach to implementing sustainable drainage systems. In December the Government took the path of least resistance and announced that sustainable drainage systems (SuDS) are to be introduced to England and Wales through existing planning policy.

In the long-awaited announcement, Communities Secretary Eric Pickles explained that local authorities will have responsibility to ensure that new developments of 10 or more homes and all major new commercial and mixed use developments include SuDS. []

Under a SuDS solution surface water run-off is managed using landscaping and underground storage solutions. SuDS is about dealing with rain where it falls, which is in contrast to conventional drainage solutions which are designed to carry run-off from a development to an outfall as quickly as possible. The new SuDS arrangements will take effect on 6th April 2015, and planning policy will be strengthened accordingly.

While the new approach may avoid delays to the planning process, it is not as far reaching and clear as the original 2012 proposal, which was based on implementation through SuDS Approval Bodies. The withdrawal of Schedule 3 of the Flood and Water Management Act 2010 and the changes to existing planning policy mean SuDS will not be a legal requirement alongside the planning process. Instead it has been diluted to a planning consideration; as such it will be down to each individual planning authority to lay down their requirements for SuDS.

Under these new arrangements local planning authorities should now consult the lead local flood authority on the management of surface water to satisfy themselves that a development’s proposed SuDS solution is appropriate under the approval process. The lead local flood authority should be able to assess the risk of surface water flooding across planning boundaries to help reduce the likelihood of flooding.

This arrangement makes sense and should help overcome concerns about the capacity and technical expertise of local planning authorities to deal with drainage issues. A proposal to make the lead local flood authority a statutory consultee is the subject of a new consultation, which closes on 29 January.

That said, this is a piecemeal approach, with individual local authorities consulting with individual lead local flood authorities, which could result in inconsistencies nationally that may lead to disputes occurring between developers and local authorities.

The ongoing maintenance of SuDS is a concern despite the SuDS approval process requiring local authorities to ensure developers have ‘economically proportionate’ arrangements in place for maintenance over the lifetime of a development. The issue of SuDS ownership is crucial; for example, maintenance could be carried out by the local authority, water company or by a private contractor, which means there will be less certainty over who actually has responsibility for a scheme’s maintenance which could leave property owners saddled with high maintenance costs.

SuDS will only apply to medium and large scale developments, those of 10 or more homes and major commercial and mixed-use developments. The Government says this threshold is to avoid “excessive burdens on business”. However, developers could exploit this loophole with partial development of plots in stages of up to nine homes at a time. Furthermore, there is no reference to the size of the properties or square area of the total development site.

Similarly, if there are a lot of small developments in an area the cumulative effect of run-off from all of these may not be addressed. However, the 10 home-trigger is a practical starting point for the new rules, provided the threshold is reduced over time.

Eric Pickles announcement also gives developers and planners a SuDS opt-out clause: SuDS do not have to be provided if they can be “demonstrated to be inappropriate”. As such, this could allow planners to choose not to insist on SuDS when the costs associated with them are deemed to affect the viability of a development. So, if an authority is set on developing an area, it can do so regardless of the consequences on drainage.

It is also worth noting that with this announcement the government has chosen to adopt a far narrower definition of SuDS than the one generally accepted as best practice. Water quantity and flood mitigation are referred to at length, but water quality, amenity and biodiversity are given far less prominence.

The CPSA’s members welcome the introduction of SuDS as part of a range of drainage solutions to help protect people and property from the risk of flooding. As manufacturers of dependable SuDS components, including flood control, attenuation and underground storage systems, CPSA members are able to work with designers and installers to provide precast concrete SuDS solutions that offer excellent whole life value. For more information on Sustainable Urban Drainage Systems follow the link.

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