THE really unpleasant thing about floods, which isn’t conveyed in TV footage of people collecting groceries by canoe, is that they turn streets and homes into open sewers. It’s disgusting, a severe health hazard and it takes weeks to get rid of the stench.
Londoners have so far been spared shit in the streets. But after heavy rain the Victorian sewer system cannot cope. On some 50 occasions in 2000, a year of exceptionally heavy rainfall, London’s sewer system was in danger of overflowing. There was no choice but to open the valves and let the filth flow into the Thames. So far this year there have been at least 13 such discharges from the Mogden and Hammersmith sewage plants in west London alone.
Three London buses
Britain is obliged under EU agreements to stop pumping excrement into its rivers or face big fines. As recently as 2012, the European Court of Justice ruled that the UK was failing to fulfil its obligations under the urban waste water treatment directive of 1991.
One possible solution, though not the only one, was to upgrade sewage works along the Thames and build a gigantic tunnel under the river to channel away all the poo. And so, more than a decade ago, the Thames Tideway Tunnel project, aka “the Supersewer”, was born – a 15-mile bore wide enough to take three London buses. It will start near Acton in the west and emerge at Beckton in the east, its contents having been pumped up from 65 metres below ground. Thames Water hopes it won’t cost more than – gulp - £4.8bn – three times more than the original £1.7bn estimate.
Such a big project got engineering companies salivating, while accountants rubbed their hands at the prospect of interesting financing options. But alarm bells have been ringing elsewhere for some time. The project proposes to give carte blanche to a monopolistic company with a track record of tax avoidance to spend huge sums on a piece of infrastructure of debatable value, all underwritten by taxpayers. As Sir Ian Byatt, a former head of Ofwat, told a meeting at the House of Lords last year: "This is a PFI project squared in terms of what could go wrong.”
Impact in their wallets
Thames Water’s customers will soon feel the impact in their wallets. The company says it has no money left to pay for the tunnel, having given some £3.6bn to shareholders since 2000, when the tunnel was first mooted, while not setting anything aside. It wants to raise water bills by around £70 to £80 a year for its 14m customers. Thames Water’s clever Cayman Island financing means it pays virtually no corporation tax, so any financial benefit of the project will go to the firm’s owner, Australian investment bank Macquarie, and a few other investment funds.
In recent months an increasingly convincing attack has been mounted on the technical necessity for the supersewer, led by the very experts who initially welcomed and researched it, such as Professor Chris Binnie, specialist in water resources, water supply and flooding, who chaired the team that sought a solution to the problem in 2005, and Professor Richard Ashley, Emeritus Professor of Urban Water at the University of Sheffield, and an international expert in “flood resilience”.
While millions have been spent on preparatory studies for the tunnel, no in-depth study has yet been carried out on alternative methods, such as green infrastructure, or a combination of less expensive and intrusive methods.
Permeable car parks
Elsewhere, in cities such as Philadelphia, New York and Copenhagen, “sustainable drainage systems” (SuDS) are the favoured solution. Rain water is managed sensibly and treated as a resource, not as waste. Storm overflows are slowed by various methods so existing systems can cope; they are kept separate from sewage, and the water can be harvested, not just shed as polluted flood excess. Porous asphalt, permeable car parks, more tree and green roof planting and low maintenance planting alongside pavements could do away with the need for a massive sewage tunnel.
By 2011 Thames Water had thrown £100m into research on the supersewer, but only about £200,000 has been spent researching alternatives. The main engineering company keen to be involved in “delivering” the supersewer is CH2M Hill, veteran of the London Olympics and HS2 projects and main sponsor of the “London Lounge” luxury lobbying marquee at both Tory and Labour conferences (Eyes passim).
The government, parroting Thames Water, still claims the tunnel is crucial to avoid huge EU fines, but it is increasingly likely a combination of green infrastructure, SuDs, plus smart monitoring and control devices, would satisfy the European Commission – and at a much more reasonable price.