At Tideway's Putney Embankment Foreshore site, the team has recently completed the civils works in the penstock/interception chamber. This includes construction of the chamber itself, all the internal walls as well as the the roof slab to close off the structure, which was poured back in October.

The structure is nicknamed the 'penstock chamber' by the team at Putney, as it is the chamber which holds the main penstock.

A penstock is essentially a valve which controls or isolates the flow of liquid – in this case, sewage.

The chamber is the structure that will hold the volume of untreated sewage, once intercepted from the Putney Bridge combined sewer overflow (CSO), until it is subsequently released into the main tunnel by automatic control of the penstock valves.

The penstock chamber structure was sitting above ground over a year ago and has been sunk into position and fitted out with the remaining civil works.