Sustainable Urban Drainage Systems (SuDS)
Surface water run-off should be controlled as near to its source as possible through a sustainable drainage approach to surface water management (SuDS). SuDS seek to mimic natural drainage systems and retain water on or near to the site where rain falls, in contrast to traditional drainage approaches, which tend to pipe water off site as quickly as possible.
There are many different sustainable drainage system features available to suit the constraints of a site. These include green roofs and more natural features such as ponds, wetlands and shallow ditches called swales.
Hard engineered elements are often used in high density, commercial and industrial developments. These include permeable paving, canals, treatment channels, attenuation storage and soakaways.
SuDS offer significant advantages over conventional piped drainage systems in reducing flood risk by reducing the quantity of surface water run off from a site and the speed at which it reaches water courses, promoting groundwater recharge, and improving water quality and amenity. The range of SuDS techniques available means that an approach in some form will be applicable to almost any development.
Major development proposals are now required to incorporate SuDS, paying due regard to the following:
Where this is not practical it must be demonstrated that an acceptable alternative means of surface water disposal is incorporated.
Drainage systems considered at the earliest stages of site selection and design are easier to integrate into developments and therefore the Council encourages prospective developers to engage in pre-application discussions.
A revised Validation Checklist for major developments is currently being developed and will specify what the Council will expect to see at each stage of the planning process, in terms of surface water.