Sustainable drainage in a new housing development
Cambridge Housing Society development of a small scale affordable housing development in Cambourne (35 dwellings, 1ha site). Sustainable drainage features included in design and construction, permeable paving, detention basins, swales, green roof demo, water butts.
There is growing pressure for new housing in the UK. Cambridgeshire is a key growth area under the government’s housing strategy, with up to 50,000 new houses planned to be built by 2016. The Water Framework Directive has a target of good quality ground and surface water by 2015.
It is also a relatively low-lying county where flooding in river valleys and urban watercourses is a major concern. The area is susceptible to combination events – where pluvial, fluvial and tidal flooding can occur together. There is also a high water table and a layer of impermeable clay, both of which contribute to the flooding risk.
Key messages and learning outcomes
Opportunities exist for the installation of sustainable urban drainage systems (SUDS) measures even in small developments. Need specialist advice depending upon the scale of the development/installations.
Generally, SUDS can bring reduced risk of flooding, replenished groundwater levels, new habitats for wildlife, cost savings, reduced water consumption and improved water quality returning to the cycle.
Approval of residents
Cost savings – for development and for householders (no storm water drainage charges).
The use of public open spaces, including adjacent, off-site open spaces, provides a viable solution to the problem of accommodating softer landscaped SUDS within housing developments. This will become more of an issue due to the Government’s policy within PPS3 of higher density developments (from Lamb Drove case study on Ciria website).
Wendy Hague, Cambridgeshire County Council, 01223 715533