The Thames Tunnel Commission (TTC), chaired by Lord Selbourne, said a shorter tunnel could be combined with new green technologies to do the same job as the proposed 32km ‘super-sewer’.
The commission is sponsored by the London Borough of Hammersmith & Fulham Council, with the support of other London boroughs including Southwark, Richmond and Kensington & Chelsea, which are opposed to the plans.
Thames Water wants to build the tunnel to capture and transfer sewage from 34 combined sewer overflows that currently discharge directly to the River Thames.
But Lord Selbourne said: "Our forensic analysis shows there is a substantial body of evidence pointing to the fact that there is a smarter way to make the River Thames cleaner.
"A shorter tunnel, combined with green infrastructure solutions that are built up incrementally in the medium to long-term, would be both compliant with EU directives and less costly and disruptive to Londoners. These alternatives require further study."
Recommendations of the TTC report included:
- Urgently revisiting the primary reasons for rejecting proposals for a shorter EU-compliant tunnel that costs less than half the super sewer
- Considering complimentary green infrastructure solutions that minimise the amount of fresh rainwater entering the sewerage system
- Giving very careful consideration to the other alternatives as proposed by Chris Binnie, chairman of the Thames Tideway Strategic Study Group from 2000 to 2006, and professor Colin Green, who is a national expert on water economics
- Examining the experience of other EU member states in complying with the Urban Waste Water Treatment Directive and taking note of the experience of world cities like Chicago and Milwaukee.
Plans for the Thames Tunnel are out to public consultation until 20 December.