London 'Supersewer" plan causes stink Data seen by The Sunday Telegraph shows that, shortly before 5pm, as the Royal barge Spirit of Chartwell approached Tower Bridge, London's Victorian sewers hit capacity and overflowed. Plumes of pollution were sent spewing into the Thames, from overflow outlets lining the length of the pageant route. This week, the company is expected to announce its finalised construction plans, following two years and three rounds of consultation. A period of public scrutiny will follow before the plans are submitted to the Planning Inspectorate early next year. The 7.2 metre (23ft) diameter tunnel would run for 220ft below ground, following the route of the Thames for 15.5 miles. Due for completion around 2022, it would be the longest and deepest tunnel on mainland Britain and, Thames Water says, would prevent such sewage overflows for at least the next 100 years. But the project has faced fierce criticism, particularly from those who live near the construction sites who would face years of disruption. Local councils argue cheaper and less disruptive alternatives are available, and have attacked the impact on bills. Thames Water sewerage bills were £123 last year in the capital - the lowest in the country, while its water bills are among the highest. To pay for the Supersewer, sewerage bills may rise from next year and, after construction begins in 2016, may leap by £80, to £203 in 2011 prices.