As George Osborne prepares to put infrastructure at the forefront of his autumn statement next week, the £4.2bn London super sewer is the latest big project to raise questions over whether it merits taxpayer support.
The 15-mile Thames Tideway Tunnel is facing further controversy after an expert who approved it described the spiralling cost as a “waste of money for very limited benefit”.
Professor Chris Binnie, who chaired an assessment team that supported the super sewer a decade ago, is now questioning its value for money as diggers prepare to move in. “The tunnel will do what it says it will do. But it is almost certainly a stupendous waste of money for very limited benefit,” he told the Guardian.
Such concerns matter not only to the 15m Thames Water customers whose bills will increase to pay for the project, but also taxpayers across the UK because the government has agreed to provide “financial support” for exceptional cost overruns during construction of the tunnel, which stretches from west to east London along the Thames.
Despite opposition from residents lining the construction route and green campaigners, the government gave the final go ahead for the project in September when it accepted the Planning Inspectorate’s verdict that the tunnel should be built.
A group of academics, environmentalists and engineers, including Binnie, criticised the government’s decision, warning it would “be of significant detriment to London’s future growth, international reputation and prosperity”. They added that “a few minor works” are all that is needed to ensure the capital’s sewage system copes with flooding.
The key to Binnie’s about-turn is cost and the permanent uplift of at least £80 per year in the bills of Thames Water customers. The cost has spiralled from an initial estimate of £1.7bn to £4.2bn, the point at which experts believe the value of the benefits no longer justify the expenditure. Binnie, who headed the Thames Tideway Strategic Study Group in 2005, hopes it will not be too late to scrap this multibillion-pound solution to improving water quality in the Thames. He believes smaller measures can deliver acceptable improvements much more quickly and at a substantially lower price.
“Since the tunnel was chosen, in the intervening 10 years, technology has moved on much and techniques such as sustainable drainage systems, real-time control of sewer flows, floating booms to retain floating litter, sewer separation and the like have been developed and are now widely used elsewhere.”
Binnie said Thames Water has created the impression that the Tideway Tunnel is needed to bring the antiquated Victorian sewer system built by Sir Joseph Bazalgette up to modern standards. According to the tunnel’s backers, the project “will tackle the problem of overflows from the capital’s Victorian sewers for at least the next 100 years, and enable the UK to meet European environmental standards.” But, according to Binnie, the existing system is much sounder than suggested.
“I have been down into the Bazalgette sewer system and it is in remarkably good shape. When the sewers are loaded with dry weather wastewater they do not spill. The biggest problems occur when the interceptor sewers are unable to cope with severe localised summer thunderstorms and need to spill into the river, as they were designed to do.”
Labour peer Lord Berkeley, an engineering and tunnelling expert, is also concerned that too few alternatives have been assessed.
Berkeley said: “This is Big Project Mania. George Osborne believes big is good because it creates jobs and fat fees for his friends in the City. That may be acceptable if it was the right project but the Thames tunnel is the wrong project. It is not needed, there is very likely to be a cost overrun and what benefits it brings will not be delivered until after the project is completed in 10 years’ time.
In response, Thames Water points to a report by the Department for Environment Food and Rural Affairs (Defra) which published a positive cost and benefits analysis for the project in 2011.
Binnie has challenged the Defra report. “It is expected of most projects that are publicly funded that the projected benefits must exceed the costs by a ratio of generally 4.The Defra 2011 cost benefit study concluded a ratio of about 1, far below the norm,” he said. “However this was based on assumed benefits for ecology and health which have now been found to be excessive. My review of the Defra cost benefit, updated to February 2014, and based on the more recent data, shows the benefit to be only about £180m compared to the 2011 cost of £4.2bn.”
Defra’s guidance documents also suggest that a combination of other measures should be studied with the potential saving of several billion pounds, but those studies have not yet been conducted. Instead Thames Water insists that the river is being polluted and therefore needs the tunnel.
“It is fundamentally environmentally wrong to use London’s iconic river as an open sewer and discharge tens of millions of tonnes of sewage into it every year,” Thames Water said. Referring to the alternatives mooted by the project’s critics, Thames Water added: “Years of study have shown that all the suggested alternatives to the Thames Tideway Tunnel would be ineffective, more expensive, more disruptive, take longer, or all four.”
Binnie points out it is not tens of millions of tonnes of sewage that is discharged into the river each year. Discharges only occur during storm events. What is discharged over a year is tens of millions of tonnes of storm water with a variable sewage component. The proportion of foul sewage in combined sewage can be as low as 5%.
According to Thames Water’s own figures the amount of water supplied in London will fall by 10% between 2006 and 2030. The super sewer is planned to open in 2023 but even by 2040 Thames is forecasting it will be supplying less water than in 2006. This suggests that with less water in the system, the spill frequency and volume would be less than it was eight years ago – even without the tunnel.
“I do not know why there is such a bandwagon rolling,” said Binnie.
