The Consumer Council for Water (CCWater) is warning that the cost of the Thames Tideway Tunnel scheme to Thames Water’s 5.3 million waste water customers must be kept to an absolute minimum.

The water watchdog said it intends to keep a close eye on the £4.2 billion ‘super sewer’ scheme following confirmation by water industry regulator Ofwat that the Tunnel will be financed and delivered by Bazalgette Tunnel Ltd, a consortium of independent investors.

CCWater has been pushing hard for several years for Thames Water and Ofwat to keep the cost of the scheme and its impact on customers’ bills as low as possible.

Sir Tony Redmond, London and South East Chair for CCWater, said:

“We are pleased that they have listened and have responded positively to what we have been saying.”

“It is good news that Thames Water has announced a significantly lower bill increase than it had previously predicted, but we are concerned that its waste water customers will see their annual bills rise eventually by between £20 and £25, before inflation (including the £7 already in bills for 2015-16).

“This is an increase for all Thames Water’s waste water customers, including those outside London. We will make sure that Thames Water does everything it can to help those low-income customers who are currently struggling to pay their bills and who will feel the impact of this rise the hardest.

“And although Thames Water says its current average household bill for water and wastewater is expected to stay at its current level, before inflation, until at least 2020, there is some uncertainty about what will happen after that.”

Now that Bazalgette Tunnel has been confirmed as the infrastructure provider for the scheme and building work on the tunnel will start next year, CCWater said its focus would now be on ensuring that Thames Water keeps to its promises.

Sir Tony added:

“We will be keeping a close eye on the Thames Tideway Tunnel as it progresses over the next seven years to make sure that the costs of the scheme are continually scrutinised and reviewed, and that it delivers proper value for money for customers.”

CCWater will also be working with both companies to ensure that once the project gets under way any contact from customers or local residents is dealt with appropriately - whether this is an enquiry, complaint, request or claim for compensation.

 The independent watchdog for water customers in England and Wales has helped over 300,000 customers with complaints or enquiries about their water and sewerage services and secured over £20 million in compensation and rebates since 2005, including almost £2.2 million for customers in Wales.