Planning process must take into account sewer flood risk

In an announcement on 14 March, the Ofwat National Customer Council (ONCC), the organisation which formulates the views of water customers in England and Wales, expressed its support for the Government’s proposals for reducing flood risk through the planning process. However, the organisation added that water and sewerage companies should become statutory consultees in the planning process, and that planning permission for new developments should not be granted unless the design and capacity of the existing local sewer system has been checked and approved.

Concern over flood issues should not just be confined to coastal and flood plains, says the organisation, as a contributory factor to sewer flooding incidents is often the inability of the drainage systems to cope with increased surface water run-off from new developments. Planning authorities also need to be alert to the fact that a development in one part of a catchment can increase run-off and create a flood risk elsewhere.

“The number of complaints is increasing, and all too often, our investigations establish that properties prone to sewer flooding are on new developments which have been built on a flood plain, near to a river bank, or on land with a history of flooding,” said Sheila Reiter, chairman of ONCC. “The existing drainage systems are often unable to cope with the increased surface water run-off from new developments.”

“We know what trauma and inconvenience sewer flooding causes customers, which is why we have always argued that this issue deserves greater recognition by the planning authorities.”