What makes sustainable drainage a success? Who is responsible for sustainable drainage and who benefits?
The answers to these questions used to be obvious. The local authority managed local public services for the local people. Decisions that impacted our physical and economic environment were made locally and what was good for the local authority was likely to have held value for a least a portion of the local population. Proper management of surface and foul water kept roads clear and rivers clean, which in turn helped the local economy. This is the means by which the local authorities generated income. This is a rather simplistic description and the reality was certainly more complex.
However, in recent years, a new layer of complexity has been added with the introduction of Irish Water: what was traditionally a locally focused service now has a national and indeed global agenda.
I have carried out extensive research in recent years into what conditions make sustainable drainage a success or an irrelevant “add-on”. This examination has highlighted the need for the engineer to play a more visible role in matters of public interest.
This article identifies the key barriers to the uptake of sustainable drainage systems (SuDS) in Dublin and suggests how these can be overcome.
Drainage and history of urbanisation
The challenge of drainage has been with us since man built the first settlements. In Ireland, our oldest cities are located beside water, often in low lying areas likely to flood. Initially, the solution was thought to be in conveying runoff to the nearest stream or river as rapidly as possible. In the fullness of time, we realise this approach has contributed to the pollution of our watercourses and flooding. It has taken us a long time to understand that the solutions to our drainage infrastructure needs are to be found in nature.
SuDS philosophy is to mimic the water cycle. SuDS offers a return to nature by promoting; the temporary storage of surface water (ponding), infiltration, the harvesting of rainwater at source, evaporation, evapotranspiration, groundwater recharge and the re-use of storm water.
Given that SuDS policy came into being in the Dublin region in 2005 for new developments, uptake has been slow. Now, Irish Water provides new challenges and opportunities for the adoption of successful storm water management policies.
What is SuDS?
SuDS is drainage that mimics nature. Its purpose is to:
- enhance our social amenity;
- drive economic growth;
- protect us from flooding; and,
- protect and enhance the quality of our rivers and streams.
In Ireland, we tend to think of SuDS as primarily a flood management tool and a mechanism to provide us with cleaner water. In countries where it is more firmly established, it is also seen as a means of making our cities and towns more attractive and thereby attracting greater investment.
Why have we been slow to implement SuDS in Ireland?
Given that SuDS has been policy since 2005, why is it that you can walk through our towns and cities and not come across a SuDS feature? The reasons are as follows:
- There is no leadership driving the SuDS agenda in Ireland;
- There is an absence of public awareness and understanding of SuDS;
- SuDS policy in Ireland is restricted to new developments requiring planning permission only;
- There are no incentives for developers to incorporate SuDS in their schemes;
- There is a lack of resources within the local authorities to monitor new developments;
- There is no policy to promote SuDS retrofit to the existing building stock and public roads;
- There are inconsistencies in the application of the existing policy throughout river catchments; and,
- There is a lack of regulation governing the quality of stormwater discharges.
How do we overcome the barriers to SuDS adoption?
International best practice tells us that we need a single organisation with responsibility for water management including foul drainage, water supply and storm water management at catchment level. This organisation needs to be supported by strong, political commitment, at national and local level, to educate, incentivise and inform communities of the benefits of SuDS.
This is not the Irish model. Irish Water is responsible for the foul and combined sewer systems (the agglomeration licensed by the EPA), but excludes surface water sewers. More fundamentally, it is removed from the local arena with no accountability at local level.
Education and public awareness programmes are required to encourage SuDS retrofit schemes and to garner support for new legislation; regulations and the potential introduction of charges for households and roads authorities for storm water discharges.
The political consequences of flooding has led to policies that focus on flood mitigation – pushing the wider environmental and social benefits of SuDS into the background. This is reinforced in planning policies where restrictions are placed on the rate of surface water discharge only.
We must start setting quality standards to all storm water discharges – a guiding principle in storm water management in the US and Australia for decades. We also need financial incentives to encourage the implementation of SuDS systems in new developments and SuDS retrofit.
The local authorities need to invest more heavily in the training and education of staff across all departments in relation to SuDS. They also need greater resources to monitor and enforce the implementation of SuDS in new developments.
What we can learn from the international experience?
The good news is that the challenges we are experiencing in the implementation of SuDS are not unique to Ireland. In fact, countries such as Australia, US and the UK have encountered many of the same difficulties along their path to achieving successful stormwater management practices.
Internationally, it is accepted that these barriers can be overcome through strong governance processes. There is widespread recognition that multiple entities with responsibility for water management throughout river catchments impede effective SuDS implementation;
The importance of both ‘top down’ (regulatory) and ‘bottom up’ (incentive/assistance) approaches to encouraging SuDS implementation in new developments and SuDS retrofit is accepted and demonstration projects are regarded as a very useful tool in educating and garnering acceptance of household charges for storm water discharges.
How water management is changing with the advent of Irish Water
One of the key drivers of SuDS policy has been highlighted as the removal of surface water from the combined sewer system, to lessen the frequency of combined sewer overflow (CSO) spills and to reduce the cost of treatment at treatment plants. A significant issue facing Irish Water is the extent to which it is viable to retrofit the removal of storm water through SuDS, as opposed to building storage at CSOs and dealing with it at treatment plants.
Identification of suitable locations, prohibitive costs and technical challenges with the retrofitting of SuDS in urban roads remain. Equally, the reluctance of roads authorities to adopt SuDS as well as the scepticism that exists in the road/highway engineering fraternity is a barrier.
Unless Irish Water has the power to levy the roads authority (local authority) and property owners discharging to the foul/combined network, it is unlikely that the retrofitting of SuDS will occur to any significant degree. Consequently, Irish Water may inadvertently reinforce the tendency towards surface water attenuation with the wider social and ecological benefits of SuDS being ignored. This could be overcome however, if the longer term benefits of SuDS are considered and a funding model agreed between water resource stakeholders.
Arguably, the transfer of responsibility for water service functions will diminish the role of locally elected representatives in relation to the provision of water services, development control, land use planning, strategic planning and accountability. Most importantly however, decisions on the allocation of water resources will be made by a national body removed from the local arena, with little accountability at local level.
Hundreds of thousands of Irish citizens took to the streets to protest at the imposition of water charges. The ensuing political upheaval leading to the postponement of water charges, provides us with an opportunity. Water is now at the forefront of social consciousness. It is hard to recall a time when an ‘engineering’ issue held such a profile in national debate.
Water must be recognised as a valuable resource. Most people would accept that water charges will be reintroduced at some point in the future. Internationally, the need for political commitment aimed at community values driving the decision-making process, working alongside a single organisation with responsibility for foul drainage, water supply and stormwater management (at catchment level), is recognised as fundamental to the effective implementation of sustainable stormwater management.
This challenge requires a multi-disciplinary approach across all sectors of society including professionals such as engineers, architects, planners, central government and local government sectors and the general public. It is incumbent on us professional engineers, as experts, to lead the way. We can, and should, commit to SuDS now.
Author: John Paul Rooney is an associate with Roughan & O’Donovan Consulting Engineers and leads the water engineering section of the company. He is a member of the Engineers Ireland Water and Environmental society, and for the past 14 years has worked as a contractor and consulting engineer on a broad range of civil and structural engineering projects for the public and private sectors. In recent years, he has undertaken research examining the effectiveness of national, regional and local sustainable drainage policies in Ireland and abroad.
In September 2016, he will be providing a series of seminars on how current SuDS policy could be communicated and implemented more effectively and will discuss new policy initiatives which should be adopted in Ireland. For more information, please e-mail johnpaul.rooney@rod.ie