Work on London’s new 25-km-long "super sewer" will start next year to update the city’s creaking Victorian sewerage network and stop millions of tonnes of raw sewage overflowing into the River Thames.
The green light came yesterday after the scheme’s private-sector investors confirmed they were on board.
Sharing the work on the $6.3bn, six-year-long project – called Thames Tideway Tunnel – are three consortia made up of heavyweight contractors from UK, France and Spain.
The scheme will be the largest infrastructure project ever undertaken by the UK water industry–
It also emerged yesterday that the client for the work will be Bazalgette Tunnel Limited, a special-purpose company separate from Thames Water, Greater London’s private water utility.
The new company is named after Sir Joseph Bazalgette, the Victorian engineer who tackled London’s "Great Stink" by creating the city’s pioneering sewerage system throughout the 1860s and 1870s.
Thames Water also announced yesterday a lower-than-predicted project cost, which it said meant that the average household bill for water and wastewater of around £370 per year is now expected to stay the same, before inflation, until at least 2020.
"It’s a historic achievement and I look forward to supporting Bazalgette Tunnel Limited in ensuring the project is delivered safely, on time and to budget," said Martin Baggs, the chief executive of Thames Water.
Elizabeth Truss, the UK’s secretary of state for the environment, said the tunnel would be "a fantastic example of world-leading British engineering", and would generate more than 9,000 jobs.
Big enough to drive in
Running beneath the Thames, the tunnel will be 7.2m in diameter – wide enough for two cars to drive in side by side – and 35m deep at the shallowest point, descending one metre every 790m to ensure water flow.
The system is expected to reduce the 39 million tonnes of untreated sewage that currently overflow into the tidal Thames in a typical year. That’s equivalent to eight billion toilets flushing straight into the river, according to Thames Water.
Bazalgette’s Victorian network is still in good working order, but now lacks the capacity to cope with the capital’s rapidly growing population, Thames Water said.
Bazalgette Tunnel Limited is backed by pension funds and other long-term investors represented by Allianz, Amber Infrastructure Group, Dalmore Capital Limited and DIF.
The scheme will be the largest infrastructure project ever undertaken by the UK water industry.
Work is split into three sections, west, central and east.
The west tunnel will be built by joint venture between UK’s Balfour Beatty, BAM Nuttall and Morgan Sindall.
Building the central section is a joint venture comprising the UK arm of Spain’s Ferrovial Agroman and UK’s Laing O’Rourke Construction.
The east tunnel will be built by a team made up of UK’s Costain and French-owned firms Vinci Construction Grands Projets and Bachy Soletanche.
The system integration contract has been awarded to Amey, which will be responsible for providing process control, communication equipment and software systems for operation, maintenance and reporting.