Comments on: LONDON SUSTAINABLE DRAINAGE ACTION PLAN – draft for public consultation

Emeritus Professor Richard Ashley,  12^th November 2015

Now that Schedule 3 of the Flood and Water Management Act 2010 has not been commenced, England is in a rather uncertain position regarding the promotion of the use of SuDS and who should shoulder the responsibilities for longer-term maintenance and operation. This is despite changes to DCLG’s National Planning Policy Framework that appears to reinforce encouragement for the use of SuDS through the planning system. Therefore, the Mayor’s sustainable drainage action plan is welcome, especially in terms of it’s comprehensive look at the various ways and means as to how SuDS can and should be used for both new developments and also for retrofitting the extensive existing building stock in London. As an aspirational plan it is all encompassing in addressing the key players and stakeholder groups and the role they can play in achieving the desired 25% reduction in London’s surface water flows by 2040. Although it is rather disappointing that we shall have to wait for 25 years before SuDS becomes effectively business-as-usual in the UK’s Capital City. Despite this, the achievement of a year-on-year reduction of 1% surface water flows without a dedicated funding stream will be hard to achieve.

The plan rightly identifies that encouraging the use of SuDS for all new developments should be relatively straightforward, although the maintenance responsibilities would still remain a major issue now that SuDS Approval Bodies (SABs) will no longer be taking this on. There are much more opportunities in retrofitting existing buildings and spaces and the aspiration that this is easiest done when part of routine refurbishment or other redevelopment is sensible as this will minimise costs. Although the thorny issue of longer–term maintenance responsibilities would still need to be resolved. The proposed actions, scheduled in some detail towards each main stakeholder group notably miss this, arguably the most important issue.

The plan makes reference briefly to the need to manage water as a cycle, recognizing surface water as a resource, although nowhere does it link to the now very clear alarm signals that there will be severe water stress due to the changing climate in the South East of England within the 25 year period of the plan as it unfolds. All surface water is a resource and the plan needs to be more forthright in recognizing this and promoting and integrated approach. Water Sensitive Urban Design (WSUD) is also referred to in the plan, however, as one of the originator’s of the concept, I find the definition too narrow as it does not include land use planning and urban design. Overall the plan fails to link well to the need to use SuDS as part of a WSUD approach to create better places. By starting from the concept of a ‘SuDS action plan’ – the wider scope that is really needed is already constrained. Given that SuDS have been with us for decades now, the playing down of the need to take an integrated approach is disappointing in a strategy document. The asserted vision to ‘manage rainwater sustainably’ and what follows in the actual plan misses many of the crucial components of doing this.

The plan avoids mention of the presence of the London Tideway Tunnel; presumably functioning by 2040. The tunnel is being built only because the capital sees rainwater as a ‘problem’. With the ‘sustainability’ vision asserted and as the plan unfolds, it is possible the £4bn tunnel will become obsolete as the uptake of SuDS and other WSUD techniques turns ‘the problem’ into a wide range of opportunities, which may also make the London desalination infrastructure irrelevant.

Despite its’ limitations, the plan nevertheless is a step in the right direction in highlighting the potential for SuDS in the capital and a vision for how they may be more effectively implemented.

To read the consultation click here:

https://beta.london.gov.uk/sites/default/files/lsdap_final.pdf

https://beta.london.gov.uk/what-we-do/environment/environment-publications/draft-lsdap