Call for SUDs in Stroud

Stroud District Council Cabinet meeting on 29th October has been put aside especially to look at flooding issues. I am hoping that we can also soon have a Policy Panel to look at Sustainable Urban Drainage Systems. I have been pushing for this for a while and have now summarised below some of the reasons why I think it is important. I am hoping this will prompt a date from the Council.

Photo: Not the SUDs we are referring to in this blog entry!

As regular blog readers may remember I have also met in the past with Bob Bray, a well-known specialist in SUDs who lives locally - he has carried out training in SUDs with planners in Bristol and other Councils who by all accounts found it very helpful. I am hoping that SDC will consider similar training or help with the Policy Panel I am proposing - particularly to hear about other SUDs schemes and the issues around adoption.

Anyhow here's what I wrote - plus some good notes from Bob Bray as to why SUDs schemes are not being developed...

Proposal for the further development of SUDs in Stroud District

1. Reasons for a Panel Policy include;

1.1. SUDs will have an increasingly important part to play in future water management. The recent floods highlighted the need to develop SUDs systems: where they existed water was managed better.
1.2. Implications of the 'new' PPS25 Planning Policy Statement.
1.3. Our Local Plan contains a SUDs requirement but this has not always translated into SUDs schemes. The Planning department has seen significant improvements in this area over recent months particularly on larger developments. It would be good to build on this and develop a more comprehensive policy for our LDF in particular highlighting the need for guidance before Detailed Planning permissions are submitted. I note that Gloucester City have developed Supplementary Planning Guidance in this area (ii).
1.4. Issues regarding adoption and section 106 need resolving - see point 2.4 below.
1.5. Need to tackle widespread ignorance about SUDs (particularly amongst some developers) - see point 2.3 below and appendix one.
1.6. Consider developing a plan of action for the District. This could include establishing a Working party with potential representation including Severn Trent Water, Environment Agency, Drainage Team, Highways, University and Planning, Environment and Regeneration departments. The role of this working party would be to provide a focus for the wider debate and research on the area’s drainage its work could include:
- Policy development
- Drafting of supplementary planning guidance and design codes
- Catchment analysis to explore amongst other things regional (multi development site) controls for flood waters etc.
- Training tailored to staff requirements plus management of SUDs schemes.
- Above all the action will be about getting more schemes on the ground, reducing people’s concerns, establishing tried and tested management and best practice and building experience.
- There may be future opportunities to advise other Local Authorities as we build capacity as leaders in SUDS.

2. Background info re SUDs taken from recent submission to flooding inquiry (i):

2.1. What are SUDs? The SUDs philosophy is an integrated approach to managing water on site by minimising run off, attenuating discharge rates, detaining water for passive treatment, improving water quality and creating amenity space for people and wildlife. The overriding concept of SUDS is that drainage design for development sites should mimic, wherever possible, the existing drainage characteristics of the area and seek to minimise the effects of development on the hydrology of the site and the surrounding environment: water will be dealt with as close to where it falls as possible (iii). SUDS can be achieved by utilising a series of porous hard surfaces, swales (broad open ditches), ponds and wetlands. These all ensure that water seeps slowly away in to ground water (as would happen naturally pre-development) or is discharged to the drainage system at a low controlled rate.

2.2. Advantages of SUDs. SUDs systems offer solutions that are often at a lower cost and lower maintenance costs to traditional systems and are more sustainable than convention methods because they:

- reduce runoff flow rates which reduces the resulting pollution from run-off
- reduce flooding and subsequent damage to water courses and more
- protect or enhance water quality
- improve habitat for wildlife
- provide a public/functional space (good examples in Sheffield and Lewisham where SUDs have been integrated into local parks) or for willow, biofuel or aquaculture
- reduce depletion of ground water flow which in turn impacts upon water resources

2.3. Ignorance and resistance. Take up in England and Wales is very poor indeed even with support from Government through PPG25 and other policy documents, and from the Environment Agency (iii). Forward thinking councils like Gloucester City are attempting to develope ways to encourage more SUDs schemes. However they and indeed most Councils, even where they have SUDs policies as part of their planning process, are not seeing SUDs schemes delivered. Ignorance and resistance within the construction industry means that drainage proposals that have been called SUDs schemes have not always delivered easily maintained, visually attractive and functional solutions. Similarly even where Local Plans have called for culverts to be opened up this has not occurred despite new developments. It is critical that greater guidance and support is provided before a Detail Planning Submission is made.

2.4. Adoption problems. One key excuse that developers use to not submit a SUDS scheme is 'adoption'. However if structures are designed correctly in the first place then maintenance costs should not be prohibitive and structures can be adopted as long as appropriate commuted sum payments are made. In traditional systems pipes are adopted by Severn Trent, for which they are allowed to charge through the water rate: typically 10 – 15% of a water bill will be for this service. If the pipe discharges into a balancing pond then it is the local authority, who, with a commuted sum will take on the maintenance of this area in a similar way to public open space. Currently Severn Trent are obliged to adopt pipes typically used in traditional systems, but refuse to adopt many of the features associated with SUDs such as swales, filter strips or French drains even though they convey water from one place to another. It is not clear why this is the case, however, it has been suggested that the current system suits them well and there is no commercial benefit to change it. Local authorities have also been reluctant to take them on board as they are unfamiliar with them, and they have no long term revenue stream to pay for their maintenance even though SUDs usually have lower maintenance costs than traditional systems.

2.5. Lack of urgency worrying. The Interim report on SUDS was published in July 2004 and there is not even an estimated date for the final report. Furthermore that Interim report did not go far enough in making use of the advantages of SUDS. Apparently a group led by the Environment Agency, including representatives of major stakeholders, is considering both the technical standards and legal issues required to underpin the future adoption of SUDS. Again this appears to lack any sense of urgency.

2.6. National guidance needed. We urgently need clearer guidance and a stronger lead from bodies like the Environment Agency. A move to adopt a mandatory and comprehensive national SUDs policy in all new developments like in Ireland and Scotland would be a significant step towards managing our water better, but in the meantime individual Councils can considerably improve their current provision of SUDs through LDFs and more.

3. Notes:
(i) See full report here (ii) Copies of their policy documents in WORD can be sent on request. (iii) See below.

Appendix One: Moving forward with SUDS

In order to move forward with the uptake of SUDS techniques we need to understand the issues and attitudes of those involved in all aspects of development. Typical reasons (and excuses) behind the lack of uptake in the use of SUDS:

Cultural shift in how we manage surface run-off. Our present day system is based on 150 years of conventional practice and in effect is about putting water into pipes.

Lack of knowledge in what SUDS are and what constitutes good design from within authorities

Managing body – most SUDS will not be adopted by ‘The water company’ therefore it falls to another body to pick up the responsibility, for example a management company or local authority.

Management resources – It is rarely possible to acquire the surface water drainage proportion of the water bill for managing SUDS therefore other financing methods are explored such as Section 106 agreements and management companies.

Land take –landowners and developers can be concerned that there will be loss of land to SUDS features reducing capital receipts or profit from development. (will not fit with PPG 3 High density developments). With good design and early consideration SUDS can form part of the incidental landscape to a development. Volume storage which is the main issue in land take can be partly achieved through under-paving storage. Regional (multi-development) volume storage could form part of a wider public amenity, for example lakes and wetlands and level grass spaces.

Siltation – People get concerned about silt levels. Experience with older systems shows that with the right design silt is minimal in quantity.

Site too steep- not a problem infact a creative opportunity. There are examples in the UK.

SUDS are too expensive – There are costed examples already available within this country and practice abroad suggests SUDS are always cheaper. However, without actually designing an alternative scheme it can be difficult to challenge consultants and developers on this issue. The capital outlay for SUDS is considered to be less because its nature is less engineered. Each scheme would have to be considered separately.

Site too flat – water can be moved at very slight gradients as the need for cleansing as in steeper piped systems is not required.

People will not accept the look of SUDS within their local environment. If systems are well designed and managed SUDS should be an attribute to communities. All evidence in Scotland, where SUDS are commonly practiced, indicate that SUDS are accepted by communities and are infact a positive contribution to the environment.

SUDS are new and an additional burden (cannot be hassled) – with the right support and the spread of knowledge and experience to individuals through training etc this can be addressed. SUDS are likely to become mandatory therefore the longer the lead in time for an authority the better.

You need a water course to drain to –Whilst this can be an advantage water in some situations can be infiltrated or put into the surface water sewer in a cleaner and controlled state.

Safety of children – schemes can be designed to make access in and around them safe for example level grass benches to the sides of shallow ponds. Regular open water is not necessarily a common feature of SUDS. It is not economical to put large storm volumes underground therefore there is the occasional need for the use of the above ground environment for storage.

Lack of skills to manage – All the features within SUDS are common within society already. Most SUDS elements would be managed as part of a landscape such as mowing verges, removing litter, strimming or flailing shallow channels, cleaning permeable paving.

Conventional drainage for the large part does a good job - why try something else? SUDS can deliver massive water quality improvements as well as amenity benefits, they are a reminder of everyone’s connection to nature and their own responsibility. With the right planning they can deliver significant volume management above and beyond the conventional 1 in 30 storm period for piped systems. Recent events illustrate that conventional systems do fail either through exceedence or through blockage. 60% of reported flooding is due to conventional drainage failing.

SUDS are too loose and unpredictable they cannot be modelled precisely enough. SUDS are designed to the same standards as conventional systems for example return periods and storage. Much can be modelled, however the water’s behaviour is more difficult to model than conventional pipes. Infiltration is difficult to predict and vegetation can slow flows more than expected. However both these aspects can add extra capacity into a system. With the right design SUDS can be very robust effective systems requiring minimal input.

People can misconnect to SUDS – this can be done for example a resident building an extension and misconnecting a toilet to a surface water drain. Presently in conventional systems this would be difficult to detect. Although finding a culprit for a misconnection can be difficult the need for more societal responsibility for our surface water is needed. Within the some projects it is hoped the promotion of the SUDS and its possible use in for example supplying a fishing lake will deliver responsible behaviour. A well designed SUDS with source control lacks the use of extensive pipework therefore there is no opportunity to misconnect to a sewer. If someone does it is more obvious.

People can abuse SUDS – this can be addressed by good design and management, regular checking of inlets and outlets as part of a landscape management. Good design should involve the reduction of vulnerable engineered solutions.

It restricts design and does not fit in with the aesthetic of development – The built character of SUDS can vary with the use of different techniques providing opportunity for integration into development in a variety of ways.

What if it fails – good design and increasing experience from all professionals will deliver good schemes. The simplicity of the designs will deliver robust systems. Conventional systems fail more catastrophically whereas SUDS fail slowly or sequentially.

We don’t need to improve water quality – European Legislation will bring in the need to address diffuse pollution.

Long –term doubts about management, pipes are some much more understood. This is where there is a cultural need to understand how we can manage our surface water differently. The more schemes the more normal it will become along with its required management. Pipes are more understood but if they fail they can only deteriorate unless there is heavy investment. Greener natural systems are more robust. What is needed is knowledge transfer between professions so this new approach can be adopted.