Question to the Department for Environment, Food and Rural Affairs:

To ask the Secretary of State for Environment, Food and Rural Affairs, what recent discussions he has had with Thames Water plc on (a) the change in capacity of the sewerage system in London required in consequence of (i) the Mayor of London's revised draft housing strategy and (ii) the projected change in the population of London by 2050 and (b) the role of the Thames Tideway Tunnel in meeting demand for capacity.

The Government has not held discussions with Thames Water on the details of the Mayor's revised draft housing strategy or any change in the capacity of London's sewerage systemrequired as a consequence of it. It is for Thames Water to take population changes into account as part of its business planning for the five-yearly price review process with Ofwat.

However, Defra is working closely with Thames Water on enabling construction of the Thames Tideway Tunnel. The Tunnel will significantly reduce pollution in the Tidal Thames caused by sewage overflowing into the River Thames from combined sewage overflows when there is significant rainfall. It will also ensure that London's Victorian sewerage system, which is currently close to capacity at certain times of day, is able to meet the needs of the predicted increase in population in central London. This is set out in the economic and strategic case for the Tunnel, which can be viewed at the gov.uk website.