US cities warn London not to bank on ‘super sewer’
Thursday August 4, 2011
Officials from two major American cities are warning Thames Water not to bank on their multi-billion pound super sewer to clean-up the Thames.
Bosses at the water-utility giant want to build a 20 mile long concrete storage tank under the river in an effort to prevent sewage spilling into the river, but experts from Milwaukee and Chicago have warned that similar ‘deep tunnel’ schemes in their cities ran over time and over budget and have failed to stop all sewage from overflowing into local rivers.
Thames Water’s super-sewer is set to cause massive disruption across dozens of sites in the capital and will cost 14 million water bill payers from Swindon to Essex an extra £120 per year for life.
Water bosses in Milwaukee, in the eastern state of Wisconsin, admitted that their tunnel had done nothing to solve the problem of basement flooding after heavy storms.
Alderman Willie Hines, the president of Milwaukee Common Council, said: “If I had billions of dollars to spend, a super-sewer would not be top of my shopping list. I would not be looking at a deep tunnel to solve all of London’s sewage problems because it certainly did not work here in Milwaukee. If I were in London's situation, I would learn from Milwaukee.
“I would only look at a deep tunnel as part of a comprehensive strategy, but it would be the third leg. The first priority would be prevention and improvement work to stop basement flooding. The second would be stopping rainwater from entering sewers by disconnecting downspouts, and setting up rain gardens and green roof initiatives. Only then would I be looking at a deep tunnel once I knew the scale of the remaining problem with sewage overflows.”
Sean Wiedel, from Chicago City Council, added: “Our storms are becoming more frequent and the deep tunnel simply can’t handle them.”
In addition to Milwaukee and Chicago other US cities, including Philadelphia and Cleveland, are looking at greener solutions – like permeable pavements, green roofs and infiltration trenches – as part of the solution as they stop fresh rain-water flooding into sewers in the first place.
Cllr Stephen Greenhlagh, H&F Council Leader, says: “It would be a massive own goal if we ignored the warnings from other major cities and spent billions of pounds on a single deep tunnel solution.
“For too long people have taken Thames Water’s word for it that their massive super-sewer plan is the best option to making our river cleaner, but now two major American cities – that have actually built deep tunnels – are warning us not to bank on this working. Evidence from across the world is increasingly showing that a more modest tunnel combined with green infrastructure solutions, that prevent fresh water from overloading the combined sewer network, is likely to be the way forward.”
Five London councils representing 1 million people are sponsoring an Independent Commission led by Lord Selborne to take a fresh look at Thames Water’s assumptions and examine whether there are sensible and more cost effective alternatives to cleaning up the river further with less disruption to Londoners and without the huge environmental, social and economic costs.
Thames Water has admitted having more than 250 people working on the super-sewer project and only a handful on green infrastructure alternatives.
Cllr Greenhalgh concludes: “The stark warnings from America make the work of Lord Selborne’s Commission even more vital as it is becoming increasingly clear that Thames Water cannot be trusted to independently examine the alternatives as they have become fixated with their massive concrete tunnel.”
For more information on Thames Water’s plans visit www.lbhf.gov.uk/supersewer.
