Nurturing nature to beat the floods

Published 12th Jul 2007

Radical steps are being taken to prevent flooding, says Sarah Lonsdale
The recent floods have sent a shiver through the bones of planners, developers and flood protection managers in London and Thames Gateway.
With 'severe rainfall events' predicted to become more frequent, sea levels expected to rise, and winter rainfall forecast to be 40 per cent more intense, the building of thousands of new homes in the estuary of one of the most flood-prone rivers needs to be questioned.
In a report by the Royal Institute of British Architects (RIBA) last month, one expert argues the only way to protect the Thames Gateway and London would be by building a 10-mile barrier from Sheerness in the south to Shoeburyness in the north, a hugely expensive plan that would struggle to find Government support.
The Association of British Insurers (ABI) has also been concerned about the Thames Gateway plans.
Spokesman Malcolm Tarling says research by the ABI concludes that climate change could increase the risk of flooding in the Estuary by eight to 12 times.
"We are not anti new building," says Tarling, "but it's a false economy to build if flooding's going to be inevitable. Insurance is for possibilities not inevitabilities."
Already developers are having to factor in flood risk on Thames-side developments. The new apartment blocks at Mast Quay, Woolwich, are built on stilts for protection, and the proposed 650-hectare park planned alongside the 10,800-home Barking Riverside development will act as a 'soft' landscape for storing flood waters.
It is not just homes in the Thames Gateway that need protection. Ian Tomes, Flood Risk Manager for the South East area at the Environment Agency, says there is greater risk of flooding to homes above the Thames Barrier.
"The risk of flooding to the Gateway area is tidal, a once every 50 to 200 years risk," he says. "But the rivers that flow into the Thames upstream of the barrier present a huge risk to people living in London." Tomes is referring to London's 'lost' rivers, Thames tributaries that have been canalised, pushed into drains, buried in concrete culverts and covered up so we can build on the valuable land: the Wandle in Wandsworth; the Fleet, rising on Hampstead Heath (once a huge river 600 feet wide where it joined the Thames near Fleet Street); or the Quaggy and Ravensbourne, Lewisham and Greenwich's rivers, now also mainly underground.
These rivers may be buried, but they still have the power to flood and cause huge damage during severe rainstorms. Parts of the Quaggy flood every two or three years and some Lewisham residents remember when the town centre was completely under water in 1968.
"I was 11 then," says Ray Manchester. "It was fun for the kids because the schools closed, but it must have been terrible for the adults."
Ray's memories have been put to good use. When, in 1989, plans to further deepen and bury the Quaggy to reduce flood risk were put forward, a group of Lewisham and Greenwich residents formed the Quaggy Waterways Action Group (QWAG).
"We thought there should be a better way than ruining the remaining natural areas of the river," says Ray, now QWAG's chairman.
"We took advice from experts. We were lucky with our timing because ideas were starting to change."
Managing urban rivers used to mean burying them in steep-sided concrete channels. It has since been realised that in times of high rainfall, the swift flowing concrete channels only worsen flash flooding.
During the 1990s, while QWAG was lobbying the then National Rivers Authority, hydrologists started thinking about new ways of managing rivers: providing a natural flood plain safely away from houses where water can pool and collect and slow the flow.
More than a decade later, QWAG's arguments combined with new thinking from the Environment Agency have launched an adventurous new plan. Sutcliffe Park in Eltham, south London, was an under-used wasteland of municipal grass.
The Quaggy flowed in a pipe underneath it for four kilometres without anyone knowing much about it. Why not break out the Quaggy through the park, bring back its natural banks, and provide a water meadow flood plain where, in times of storms, floodwater can pool and collect away from shops and houses?
The project is now newly completed and Sutcliffe Park has been turned into a wildlife water meadow in the middle of busy south-east London. Just a few steps away from Eltham High Street, with its high-rise blocks and fast food chains, are herons fishing for sticklebacks and kingfisher feasting on the insect life.
The park has now been landscaped to provide 85,000 cubic metres of flood storage, the equivalent of 35 olympic swimming pools.
"It's absolutely wonderful," says Ray. "We have good flood management, a wildlife haven and people are really proud of their little river. Before it looked like a drain and people treated it as such, chucking trolleys and traffic cones into it. Now it looks like a river again and people treat it with respect."
The Quaggy scheme could now be used as a model for other London rivers. In the meantime, residents along the Wandle are doing what they can to prevent this fast-flowing river from flooding.
"We organise monthly clear-out days," says Theo Pike, a trustee of the Wandle Trust. "Canalisation has made it flood prone and if the low bridges are blocked, Wandsworth could be London's version of Boscastle."
• Contacts Environment Agency, www.environmentagency.gov.uk; Quaggy Waterways Action Group, www.qwag.org.uk; Riba's 'Living With Water' report, www.buildingfutures.org.uk; London's lost rivers, www.fluidoffice.com
Keeping the water away
• If you're buying in a flood-prone area, check www.environment-agency.gov.uk on the website map for most-at-risk spots; during periods of severe rainfall check the site for alerts in your area
• If you're buying in the Thames Gateway, 90 per cent of which is within the flood plain, look out for developments with ground floor areas designed as garages
• Choose flats on the third floor upwards
• Form a local residents group to check that drains, ditches and culverts are clear of debris which could cause floods in heavy rain
• Think about installing a permeable surface such as gravel in your driveway to help water soak into the ground

Source: ' Telegraph '

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