Justification and Amplification: Conventional Hard Surfaces vs Permeable Pavement (Section 2.22)

With conventional hard surfaces (e.g. impermeable concrete and tarmacadam) rain and storm water is allowed to flow across such surfaces to gulleys that collect and direct water into underground pipes and drains. This can simply increase the speed and volume of flows downstream and the risk of flooding elsewhere. Permeable pavement is one straightforward example of a Sustainable Drainage System (SuDS) which can usefully contribute to a reduction in the amount and speed of surface water run-off from new development. Policy LC 3 therefore encourages greater use of permeable paving within new residential developments in locations where the future maintenance of such surfaces can be controlled by the individual householder or by a property management company. This approach to reducing flood risk is consistent with the Department's commitment to minimise flood risk to people, property and the environment as set out in PPS 15 'Planning and Flood Risk' and reinforces the requirement for developers to assess the likely impact of their developments on flood risk.