Climate change muddies the waters
A new mega-tunnel to ease the pressure on London’s sewers will not be wide enough to weather the storms of climate change, London’s Consumer Council for Water says.
By Elizabeth Pearson
Thames Water is continuing to investigate plans to build a £2.2 billion pipeline from Hammersmith to Beckton to remove excess waste water from the city’s Victorian drains instead of discharging straight into the river.
But the scheme has come under fire amid revelations the tunnel may not be big enough to cope with future environmental forecasts.
“All the engineers estimates were that if climate change continues on the sort of trajectory expected, then the tunnel probably won’t be big enough,” said the chairman of the Consumer Council for Water’s London committee, David Bland.
“Whether or not climate change is manmade is almost irrelevant. In a summer now, even with no storms and no sewage overflows, there is far too little oxygen in the water. Then, you get these instances where all kinds of muck flows over into the Thames and the combination of low water level, the oxygenisation and this coming in- everybody knows the instances of these is increasing therefore it must be the case that the men with test tubes are finding the [same] results.”
“Should not we be looking now at more long term, probably more expensive solutions but they could be spread over 30 years and deal with the biggest overflows first?”
- East along the Thames from the pool of London, E.Pearson 2009 -
The consumer council suggests the tunnel was only embraced by the British government as it was spooked by the threat of a fine from the EU after the Thames failed to meet water quality guidelines handed down in Brussels.
“They are terrified of infraction proceedings form the EU, the government was offered the tunnels solution and said ‘that’s it!’ and wrote to Thames saying, ‘let’s get on with it’,” Mr Bland said.
The EU’s environment watchdog launched legal action against the British government in October 2009 after finding the sewage overflows in breach of its Waste Water Directive.
The European Union described the sewage overflows as “too frequent and in excessive quantities”.
Hammersmith and Fulham Council believes that the tunnel plan was designed more to appease the EU than fix the actual problem.
“The tunnel is the government’s response to meeting the requirements of the EU’s Urban Wastewater Treatment Directive- [we] believe this to be a seriously flawed and short-sighted option that needs review,” the council said in an executive summary.
“In the future we shall need flexible and adaptable approaches to drainage and water storage that can be developed incrementally to respond to climate change as our knowledge and understanding of the impacts develop. The tunnel is not an adaptable nor flexible solution but rather locks us in to a single drainage solution for the next century and beyond.”
“The environmental benefits of the scheme will be outweighed by the carbon footprint that the construction and ongoing maintenance of the tunnel will create.”
But the Policy and External Relations Manager of the Environment Agency’s Thames Estuary Programme, Chris Burnham, maintains that climate change is precisely why the tunnels are needed.
“Climate change is a huge issue and it is also driving why we need a solution. In summer months, we could see 50-60 percent less flow [in the Thames] than we do now,” he explained.
“That means that if you do get discharges in the summer, the impact will be much greater because there is less water, less dilution, so the bacteria work faster, use up oxygen quicker but at the same time we are forecast to get more of these intense summer downpours. So summer downpours will push all this concentrated sewage out into the Thames.”
Thames Water is continuing to investigate potential construction sites for the tunnel across London.
