Contracts were initially set up in 2009 and were for 5 years, with the potential to extend further if both parties agree.

Costain said the confirmation of remaining AMP5 and AMP6 work pipelines would be worth £250m to them alone.

Simon Cocks, Waste Water Services Director for Severn Trent Water said: “We’ve developed successful long term relationships with all of our supply chain partners and we’re pleased that we can continue to work together as one team to maximise the benefits of these arrangements.

“The vision for the next five years is all about investing efficiently so that we continue to deliver the lowest bills in England and Wales for our customers and leave a legacy to be proud of.”

The new contracts will see all companies working together in collaboration to deliver essential investment in the region’s clean and waste water network.