Revealed: how cars cause urban floods
By Michael McCarthy, Environment Editor
Published: 07 March 2007
Why on earth would increased car ownership in urban areas lead to flash flooding? Because towns and cities are complex systems of cause and effect - and the Government needs to start thinking about that, according to a new report.
The link between more cars and more flooding may not be immediately obvious to most of us, but it is vividly illustrated in a diagram in the report, entitled The Urban Environment, published yesterday by the Royal Commission on Environmental Pollution.
Increased car ownership and use leads to demands for more roads and parking, the diagram explains. That then leads to an increase in hard, impermeable surfaces which cannot soak up rain - which in turn leads to more polluted surface water running off into drains, and in real downpours, a much higher risk of a flash flood. These sort of complex interactions are not being addressed by the Government in policy and planning, says the report, calling for the development of an over-arching policy on the urban environment.
The commission expresses surprise that the Government does not already have such a comprehensive, connected strategy to deal with the combined pollution impact of housing, transport and energy use in the towns and cities, where 80 per cent of Britons now live. It wants "joined-up" policy, it says.
"The commission are actually astonished that the Government doesn't have an over-arching urban environmental policy that takes account of people's health and well-being, the environment and transport, and tries to join up what we do to tackle these problems," Sir John Lawton, the commission chairman said.
"There are examples of good things happening all over the place. The thing is, there aren't enough of them and they are happening too slowly."
Sir John praised the recent tightening of building regulations as a step in the right direction. But he added: "I'm sorry, the rhetoric does not match what we see on the ground.
"Urban area pollution, for example, is now on the increase again, particularly because of the increase in the number of cars and other vehicles on the roads and Government has consistently failed to address that."
Sir John said he was "very fearful" that the Government was not taking seriously enough the environmental aspects of the large-scale house-building it is planning in the south-east of England.
"We are not convinced that the Government have grasped the scale of the issues that confront them in building new areas in the South-east in water supply, in the adequate provision of public transport and the whole design of these areas so people can get about more easily without using their cars," he said.
One of the commission's key recommendations is that a new urban environmental contract be established to forge partnerships between local and central government, and the private and voluntary sectors.
The report points out that the technology to improve environmental performance in towns and cities exists, but it is not being applied widely enough.
Sir John heaped special praise on the environmental efforts of some local authorities, including the Greater London Authority, headed by Ken Livingstone, Merton Council in south London and the borough of Woking in Surrey.
He said the London mayor's long-term strategy for cutting pollution in the capital showed "what can happen when a visionary individual is determined to tackle the issues".
