As London continues to grow, its sewerage system needs more capacity to meet demand.

One of the problems faced by those managing the sewerage system is that, on occasion, wastewater can overflow into the River Thames. Thames Water is tackling this problem by building the Thames Tideway Tunnel. This will capture wastewater overflows, and improve the quality of the water in the River Thames.

An ambitious build

The build has started and is due to finish in 2023. The estimated cost of £4.2 billion, makes this the biggest, single UK sewerage project since privatisation of the water industry in 1989. It is no surprise then that, given the complexity of this project, its combined costs will add to the sewerage bills in the Thames region. Around £13 of the average household bill for 2016/17 will go towards the project and this will eventually rise to no more than £25 a year, before inflation is added.

How are we involved?

We are here to look after the needs of the consumer and have welcomed assurances from Thames Tideway Tunnel stakeholders (including DEFRA and Ofwat) that construction costs will be scrutinised to ensure the final proposal represents value for money.

We are still concerned about the scale of the costs involved and how these may impact on Thames Water customers.

Protecting water users

We have supported the phasing in of any additional charges to minimise the impact on customers’ bills. We’ve pressed Thames Water to help those who may find themselves struggling to pay. For example, by offering an assistance scheme or operating a social tariff.

We’ve also asked for transparency on all project costs and, in particular, the construction costs.

While construction of the tunnel continues, CCW will keep an eye on its progress and monitor the impact on the region’s water services.