Lord Berkeley is calling on the Government to launch a new independent study into the feasibility of SUDS for London as an alternative to Thames Water’s proposed £4.1 billion supersewer.

In a letter to Lord De Mauley, Parliamentary Under-Secretary at the Department for Environment, Food and Rural Affairs (DEFRA) last week, Lord Berkeley reiterated the view that the Putney Sustainable Urban Drainage Systems Study (Putney SUDS Study) was the only evidence that the Government had relied upon in making its decisions to support the Thames Tunnel proposal over other alternatives.

The use of the Putney study by Thames Water has been criticised as flawed on a number of grounds, including:

• the small-scale nature of the study itself;
• the fact that the data is now ten years out of date – the original study was undertaken in 2002

Professor Richard Ashley who was responsible for carrying out the Putney SUDS Study, has pointed out that the underpinning modelling data for the Study supplied by the Environment Agency and Thames Water incorrectly presumed that all of the impermeable area drains to the West Putney Combined Sewage Overflow (CSO) whereas a very significant proportion discharges are not to the CSO but directly to Beverley Brook.

Lord Berkeley says in his letter that the alternative solutions to the Tunnel are considered by many experts to be more up to date and in line with holistic integrated water management solutions as required by European legislation and policy. They are also likely to be cheaper and achieve an earlier compliance with the Waste Water Directive than the Thames Tideway Tunnel. In October the UK was found to be in breach of the Urban Waste Water Treatment Directive with regard to London’s sewerage system.

Lord Berkeley’s letter comes ahead of tonight’s high-level meeting in the House of Lords to discuss the issue, where experts responsible for the SUDS approach in Philadelphia USA will be speaking. Leading global consultancy CDM Smith says that an integrated SUDS approach to London’s water related problems are likely to create tangible improvements to all of London’s environment within around six years, instead of the Thames Tunnel proposal which would only impact upon some sewage overflows when the Tunnel is operational i.e. in 13 time years at the earliest.

Lord Berkeley says that the evidence on costs for the implementation of SUDS relied on by Thames Water and by default the Government are not robust and that a new SUDS Study for London needs to be undertaken urgently by an independent team using correct data and overseen by an independent steering group,. He suggests that the group should include not only Thames Water and DEFRA, but also groups such as Thamesbank and Clean Thames Now and Always.

The letter says that only after a new SUDS Study for London is completed will the Government then be in a position to make an informed and objective choice between the Thames Tunnel and SUDS, possibly with other short term measures, as the best and most cost-effective solution to the problems of London’s water and environmental problems.

It will be interesting to see where further opposition is likely to lead – to date groups seeking to challenge Thames Water’s proposals have sought – and are continuing to seek – access to relevant information under Freedom of Information requests.

An article in yesterday’s Sunday Telegraph might offer a useful pointer – the newspaper reports that opponents of the proposed HS2 train line last week launched a High Court judicial review against the plans and that “the Government’s main justification for its HS2 rail scheme has been demolished in secret figures released to the High Court.”