19 Dec 2016
Could a greater acceptance of proprietary systems as part of a broad SuDS toolbox facilitate more widespread adoption of Sustainable Drainage Systems (SuDS) across the UK?
The results of the Engineering Nature’s Way SuDS: The State of the Nation Survey 2016 are published and reflect the views of professionals’ actively engaged in delivery of SuDS.
In our survey, we asked professionals working day-to-day with SuDS about their attitudes to proprietary systems. The vast majority (77%) agreed that proprietary SuDS are an essential part of the SuDS toolbox. Most (70%) believed that proprietary SuDS can facilitate Green Infrastructure, and 63% agreed that they can facilitate the long-term of SuDS features.
I would commend anyone involved in SuDS delivery to read the survey report, and especially the selection of over 250 personal comments made in addition to the 13 questions answered. The detailed comments also reflect opinions that a greater acceptance of proprietary systems could facilitate wider uptake, although a few still demonstrated a view that SuDS should be ‘as natural as possible’.
The respondents were evenly split about whether proprietary systems should only be considered for a drainage design after ‘soft’ options are eliminated. However, the majority (63%) did not believe that proprietary SuDS should be considered only as a last resort.
Any drainage system must be precision-controlled to achieve measurable performance targets. Otherwise no-one knows if the surface water drainage system is working as designed, or when it should be maintained. Drawing from a full toolbox of SuDS techniques helps to achieve sustainable objectives while addressing site-specific conditions, the soil and ground conditions and the topography of a site. Using proprietary systems can help to set out a predictable and repeatable maintenance schedule.
It’s clear that most of our respondents – professionals designing and seeking approval for SuDS developments and those reviewing and approving them – saw the value of proprietary systems, be they Hydro-Brake® Flow Controls, underground modular storage and infiltration, or silt, sediment and pollutant removal, as enablers and facilitators of SuDS objectives.
The four pillars of SuDS, as set out in CIRIA’s SuDS Manual (C753), stress that SuDS are not just about controlling surface water flooding, but also about protecting environmental water quality, while creating and delivering amenity to local communities where possible.
While above-ground, ‘natural’ systems may be the romantic ideal, a pragmatic engineering approach will help to successfully deliver those four pillars in as many developments as possible. Unfortunately, SuDS can still be misinterpreted by the general public, national media, and politicians.
There has been progress to see that proprietary systems, especially treatment devices, are now included in the SuDS Manual (C753). As I pointed out in an earlier blog “SuDS Manual C753 brings knowledge up to date” following the publication of this important update in guidance, the realignment of the use of proprietary treatment devices was a significant step forward.
However, our survey showed that many professionals, while welcoming the guidance, are still unsure about whether the manual would change their approach to design and construction. There is still much work to be done.