London’s £4.5 billion super sewer is open for business

For the past eight years, engineers deep under London have been building a £4.5 billion super sewer to boost the city’s capacity to handle rainfall and effluent. Four of its 21 valves have now opened. The Thames Tideway Tunnel is longer than the Victoria line, the width of three London buses, and when combined with the smaller Lee Tunnel it can handle up to 1.6 million cubic metres of sewage. The capacity is desperately needed. London’s Victorian infrastructure is struggling to keep pace with a growing population, and after heavy rainfall sewage often overflows into the Thames. The Environment Agency believes that once the remaining 17 valves open next year, the Tideway Tunnel network will reduce storm spills into the Thames by around 95 per cent and “markedly improve” the river for wildlife. Struggling Thames Water will take over once the tunnel is fully operational and its customers can give themselves a pat on the back: they’re paying for it through their bills.