Room for more action in the London Sustainable Drainage Action Plan

This post originally appeared in the KLH Sustainability blog.

Sustainable drainage systems, or SuDS, are nothing new. The conventional method of managing stormwater is to transport collect and transport rainwater off site as quickly as possible via hard infrastructure systems. The rainwater is either discharged into the nearest receiving waters or sewage treatment plant, in the case of combined drainage systems.

SuDS, meanwhile, mimic natural systems to slow down, treat and use the water before or instead of sending it into sewers or directly to open water bodies. These systems can have additional benefits beyond managing quantities of water, including biodiversity enhancement, water treatment, reduced air pollution, amenity creation, reduction of the urban heat island effect and more.

Thanks to the multitude of benefits, SuDS are being used increasingly around the world. But in the face of increasing storm intensity, and an overburdened sewer system, how does London start incorporating these systems more quickly and reliably? This past October, the Greater London Authority released their London Sustainable Drainage Action Plan (LSDAP) for consultation. KLH Sustainability submitted comments on the plan, some of our observations are discussed below.

The vision set out in the plan is that: “By 2040, London will manage its rainwater sustainably to reduce flood risk and improve water security, maximising the benefits for people, the environment and the economy.” It outlines actions and a timeframe divided by sector to begin integrating SuDS into business as usual. The plan does a great job covering realistic and necessary actions that should be 100% achievable in the given time frame. However, as a plan, it is not very ambitious and is really only the first step towards making sustainable drainage part of the mainstream.

The key to implementing more sustainable practices is investment. In a very pragmatic way, the current plan relies on existing processes and funding streams as entry points to incorporate SuDS in to planned maintenance, replacement work and planned new projects. This is very important as it is the cheapest and easiest way to ensure this planned work is implemented correctly.

To move beyond incremental changes, there needs to be commitment to new sources of financial support and partnering. The LSDAP mentions Thames Water’s twenty4twenty £20m funding programme, which helps to identify other relevant parties interested in SUDs investment. Many programmes in the US have been successful in the increased implementation of SUDs through the use of demonstration projects, partnerships and incentives funded by central government, increased water management fees or partnership with the private sector.

Additional investment is also required to enforce the adoption of flood-related planning policies by local authorities.  This leads to the second key observation: a lack of support to implement new and existing planning policies.

Last spring, SuDS were written into the National Planning Policy Framework, requiring most development to incorporate SuDS. At that time, the capacity within local authority was raised as a barrier to enforcement and it is not yet clear if the new London Action Plan has resolved this resource issue. The LSDAP should highlight how local authorities will be supported, whether through funding, expertise or enforcement. The LSDAP should use the forthcoming Sustainable Drainage Opportunity Model to identify high-risk geographic areas that are in particularly need of robust drainage requirements and enforcement.

There are additional aspects that could be included in the LSDAP, including:

The LSDAP target is “to achieve a 1% reduction in surface water flows in the sewer network each year for 25 years, resulting in a 25% reduction in flows by 2040.” The final piece of the puzzle is for the LSDAP to identify what financial benefits could be accrued through the delivery of that target using wide-spread, small-scale SuDS solutions rather than relying on expensive, single-purpose hard infrastructure solutions to handle storm flows. By articulating the long-term value of SuDS adoption across London, the LSDAP can demonstrate how sustainable drainage scheme can really contribute to a world-class, sustainable city.


Addressing Stormwater from the Comfort of my Back Yard

Rain garden turtle_ACrisostomo

I recently moved house and now that I have a garden, I’ve been thinking about the right way to manage the garden to do what’s best for local stormwater management by helping keep rainwater out of the sewer system and either saving it to water plants or letting it soak slowly into the ground. Of course, I do this type of thing for a living, but what about for people who don’t think about it everyday? How do people get information on how to do what’s right on their properties? Or when local governments or water utilities need private property owners’ help, how do they get people interested at all?

Last month, I had the honour of presenting some of the findings of the research I led in the US on just this question at the International Water Association’s Water Efficiency conference. The conference was a chance for industry leaders from around the world to discuss leading research on everything from water rates, water efficiency and drought to smart technology, water reuse and behaviour change.

As with most things having to do with behaviour change, successfully changing the way people manage their land to help improve the greater environment can take a lot of effort. The research I did was on how to encourage adoption of small-scale stormwater techniques, such as sustainable urban drainage systems (SuDS), on private properties, found that more work and investment in the fundamentals of behaviour change, programme management and building relationships is needed to get the scale of private property participation we need to address flooding and sewer overflows more broadly.

When local agencies want to involve private property owners in being part of stormwater solutions, they can generally resort to requirements or encourage voluntary measures. Much like the UK’s forthcoming standards for SuDS, requirements tend to focus only on new construction and large developments, whereas voluntary measures can reach retrofitting of existing properties and individual parcels. These programmes can include financial incentives, such as grant programmes, cost-share, discounts, and fee credits, as well as non-financial programmes, such as giveaways and award programmes.

The research looked at programmes across the US and Canada that use voluntary methods to encourage property owners to install SuDS on existing properties, and assessed these types of programmes by comparing their effectiveness, identifying the variables that affected success and ultimately establishing more nuanced ways of approaching private property stormwater solutions.

When it comes to working with local communities on becoming part of the stormwater solution, four key lessons rose to the top. These had less to do with specifics of the technology of SuDS or complicated financial mechanisms and more on how to better engage communities.

First, there have to be clear goals behind the programme and they need to inform the approach to communicating with potential participants. For example, if counting the number of litres of water kept out of the sewer system is most important, then more work has to go into making private actions predictable, reliable, and consistent over time with clear design guidelines or performance-based requirements, long-term monitoring, maintenance, and inspections. If the goal is about education and awareness, those technical aspects may be less important and focus should be on reaching a broad audience with consistent information and developing strong communications tools like signage, educational literature and informational events.

Second, successful programmes include a personal, customized approach, which ideally comes through one-on-one interactions with property owners. Properties and conditions are different, so solutions can’t be one-size-fits-all and people don’t always know which solution is best for their property. Working together with property owners improves awareness of the problems and potential solutions, increases participation, encourages a sense of ownership and leads to stronger projects. A common way to do this is through property or site assessments, which allow for bespoke recommendations that can be more cost-effective, tailored to level of interest and knowledge and more professional applications, making for more successful projects. In some cases, this is all property owners need to go ahead and invest on their own, allowing programmes to focus financial assistance on those who don’t have the means.

Working individually with property owners takes a lot of people power, which local agencies may not have. The third key lesson has to do with partnering to spread impact. Partners can add capacity by specializing in particular topics, geographic areas, or parts of the process chain. They often have the advantage of being able to build local relationships, focus more on property owner goals rather than regulatory mandates, can be more flexible and less bureaucratic and have more freedom to experiment with innovative techniques. These partners can range from neighbourhood groups and local charities with established local relationships to social enterprises or environmental charities with expertise to private contractors or landscape designers with established businesses to even creating new jobs.

Finally, it’s important to learn from mistakes and improve programmes along the way. Successful programmes understand there isn’t one answer and use formal and informal feedback to improve. Few programmes do extensive data collection or program evaluation, but even informal feedback is helpful and those that listened to feedback, addressed problems and made changes got better outcomes.

For my garden, as a renter, I’ll probably end up with a water butt to save water for use on the plants. But for the rest of London’s gardens, advocates for SuDS, particularly as an alternative or supplement to costly hard infrastructure, can use the lessons from this research in the US to cost out and plan for approaches to scaling up local SuDS adoption and management.

Though SuDS technology is not quite ready to be sold as out of the box systems the way water efficient fixtures are, there is an opportunity to learn more from water and energy efficiency to more effectively address behaviour change in stormwater. To help people help the broader environment, we need to invest in the social side of stormwater management, including efforts on behaviour change, programme design and evaluation and improved outreach and communications.

There’s more to encouraging stormwater solutions than financial incentives

Last year I (along with the assistance of some great Research Assistants) conducted research looking at the various types of programs that local government agencies (this study focused on cities and counties in the US and Canada) use to try to encourage private property owners to do stormwater management/sustainable drainage–either grey or green–on their properties. I wrote a paper on the study for the Water Environment Federation’s (WEF) 2014 WEFTEC conference (on here or let me know in the comments if you want to see the pdf directly) and WEF published an excerpt of it in their Water Environment & Technology magazine [paywall].

You can read the article here: WET Feature 3 – Spurring stormwater solutions – Feb_15.

And if you just want a summary, here you go:

Managing stormwater in urban areas can be complicated by the fact that rain falls on property regardless of who owns it. Public investments in stormwater management can only go so far on public land before it becomes clear that engaging private property owners as part of the solution is a necessary part of making an impact. There are a large number of ways to convince property owners and occupants to manage stormwater locally and sustainably. Financial incentives are often citied as a key to getting private property owners involved in sustainable drainage systems (SuDS)/green infrastructure (GI), however, new research indicates that they may not be the answer. An examination of different types of programs across North America to encourage private property SuDS/GI action has shown that while more rigorous program evaluation is needed, it appears that financial incentive programs may not be as effective to encourage adoption of SuDS/GI as other types of programs, and to encourage substantive change, those investments may be better spent on technical assistance, individual engagement, enhanced funding for public agencies and leveraging relationships with local third-party providers.

*Updated post on 1 March 2015 to add a link to the full conference paper on since there was so much interest. Thanks for all the interest, and please do still write in the comments or otherwise let me know if you have questions about the paper or otherwise use it. Thanks!