What are Sustainable Drainage Systems (SuDS)?
SUDS are used as an alternative to conventional ways of managing surface water. The main purpose of sustainable drainage systems is to mimic the natural drainage of the site before development. This is achieved by capturing rainfall and allowing as much as possible to evaporate or soak into the ground close to where it fell. The rest is directed to the nearest watercourse to be released at the same rate and volumes as before development.
By mimicking natural drainage patterns, SuDS benefit the environment by removing pollutants - including metals and hydrocarbons from roads and car parks, before reaching a watercourse. As a result, water entering the watercourse is cleaner and does not harm wildlife habitats.
Sustainable drainage systems generally replace traditional underground piped systems that use grates or storm water drains at street level. This means any problems with the system are quicker and easier to identify than with a conventional system and are likely to be cheaper and more straightforward to rectify.
SuDS will become increasingly important for controlling surface water if rainfall levels increase due to climate change. They can also provide other benefits in developments such as passive cooling[L1] [TC2] , which will again help mitigate any increase in temperatures due to climate change.
What is the SuDS Approval Body (SAB)?
Expected from October 2012, the Flood and Water Management Act 2010, section 7, schedule 3 lays out the requirement for SUDS approval.
The Act sets out two ways in which a developer can apply to the approving body for approval of its SUDS:
- If the construction work does not require planning permission, then it can be made directly to the approving body (in the correct form, with the right level of information and with the specified fee);
- If the construction work does require planning permission then it can either be submitted on its own right or combined with an application for planning permission.
Should a combined application be submitted, the planning authority must inform the applicant of the result of the planning permission and approval for SUDS at the same time.
Further guidance and timescales for the implementation of the SUDS approval boards is due to be issued imminently. This site will be updated in due course.
Information for developers
Defra are currently consulting on national standards for sustainable drainage systems, which are intended to be implemented in October 2012. The standards will address the ways in which drainage systems are to be designed, constructed and maintained and which developers must comply. This site will be updated with these standards in due course.
The following links contain information for developers with regards to SuDS.
http://www.anglianwater.co.uk/developers/sewer-connection/suds.aspx
http://www.ciria.org.uk/suds/publications.htm
Information on paving gardens
The drains in most towns were built many years ago and were not designed to cope with increased rainfall. You may not have considered that paving front gardens can increase the risk of flooding by extra water running off and overflowing drains. However, it is possible to provide paved areas in front of your house without adding to flood risk and pollution.
The harm caused by paving gardens is not limited to just flooding. Hard surfaces such as concrete can collect pollution (oil, petrol, brake dust etc) and is then washed off into the drains. Drains can carry rainwater directly to streams or rivers where the pollution damages wildlife and the wider environment.
Planning permission is required if:
- the area of land to be covered is more than five square metres and the new surface does not allow water to run through it; or
- the area of land to be covered is more than five square metres and the new surface does not provide for the water to run to a permeable area.
Planning permission is not required if:
- the area of land to be covered is less than five square metres; or
- the new surface consists of materials such as gravel or permeable concrete block paving which lets water run through it; or
- the rainwater is directed to a lawn or border to drain naturally.
Permeable driveways are often more attractive than an expanse of concrete, and could add value to the property. These types of surfaces can also be better for the environment and do not necessarily cost more or require a lot of maintenance.
Applying for planning permission will require you to fill in an application form, draw plans (which have to be to scale) and pay a fee. Planning applications for this type of householder development should normally be decided within 8 weeks of submission.
The following links contain advice for those wishing to pave their gardens.
http://www.planningportal.gov.uk/permission/commonprojects/pavingfrontgarden
http://www.communities.gov.uk/documents/planningandbuilding/pdf/pavingfrontgardens.pdf