The appraisal study for the River Thames Scheme aims to protect 15,000 properties, mainly between Datchet and Teddington. Previous studies have costed this at around £300m.

B&V as main consultant partner will assess feasibility and undertake outline design for a 15km flood relief channel 30m-60m wide, built in three sections.

Galliford Try will undertake the bulk of GBV’s construction work when the project get full funding.

Construction work could begin as early as summer 2016 on the modifications to the first Thames weir.

Construction of the flood channel is expected to start in 2020 and take approximately 5 years to complete.

The initial study will also include costings to protect two motorway crossings, two rail bridges, 12 major river control structures and the material management associated with 140 hectares of landscaping

Matthew Nott, director for GBV, said: “In recent years we have experienced some of the UK’s worst floods, and we expect the extreme weather which caused them will become more frequent.

“This makes the appraisal work a significant step in reducing risk to more communities along the Thames.”

Once funding is secured, this major engineering undertaking will see the creation of a new flood channel running parallel to the River Thames between Windsor and Shepperton.

In addition the capacity of the weirs at Sunbury, Molesey and Teddington will be increased; and the Desborough Cut widened.