Contract awarded for first reservoir in 30 years

Portsmouth Water has awarded a design services contract to Atkins as principal designer ahead of work beginning on its Havant Thicket winter storage facility, which will be the first reservoir to be built in the UK since 1989.

Planning permission will be sought next year with work to be started on the £106 million project the following year. It is expected to be completed and filled by 2030.

Flora and fauna from the site will need to be re-homed before the embankment can be built. After that it is expected to take three years to fill the reservoir.

Bob Taylor, chief executive at Portsmouth Water, told Utility Week the reservoir was being built in Havant, which has an abundance of water from approximately 50 spring sources, to supply to neighbouring Southern Water.

Taylor said Portsmouth will export around 20 – 25 per cent of its water to Southern by 2030.

The two companies entered a bulk supply agreement allowing a transfer of 15 million litres of water from Portsmouth to Southern after the latter had to reduce abstraction from the Rivers Itchen and Test.

The river flows through both companies’ catchment area but from an environmental perspective it is preferable to abstract water from downstream rather than upstream. This resulted in changes to Southern’s abstraction licence, meaning it had to find additional water sources.

Taylor said feasibility studies and ground investigations are taking place on the site while both companies are negotiating terms and regulatory structure with Ofwat. Taylor added that the regulator has been “very supportive” of the plans as a “good example of collaboration and innovation in action”.

The project will capture excess water that currently flows into the English Channel.

Construction of the reservoir is a central point in Portsmouth Water’s proposed five-year business plan submitted to Ofwat for final determination in December.

The company said delivery of the reservoir is central to much of its plans both in terms of financeability and water resource management.

Taylor said the investment Portsmouth makes to build the reservoir will be recouped by supplying to Southern.

Atkins will be focused on the investigations, assessments and design required to submit an outline planning application in late 2020. It will also support Portsmouth’s extensive customer engagement and participation programme.

Taylor said: “We’re delighted to have the expertise of Atkins on board for what is a critical water-supply infrastructure scheme for the wider South East as supplies come under increasing pressure from climate change and population growth.”

The last reservoir to be completed in the UK was finished in 1989 at Roadford Lake in Devon.