The Regulators’ Alliance for Progressing Infrastructure Development (RAPID) has given the go-ahead for the continued development of the Poole Water Recycling and Transfer project towards its formal planning submission.

RAPID - made up of Ofwat, the Environment Agency and the Drinking Water Inspectorate - has published its gate three final decision on the project which is being developed by South West Water (including Bristol Water) and Wessex Water to help address the need to greatly reduce abstractions from the Hampshire Avon. The project also forms part of Wessex Water's adaptive plan within its Water Resource Management Plan (WRMP).

The Poole Water Recycling and Transfer project will be putting up to 30 megalitres per day (Ml/d) of recycled water into the River Stour during a typical summer, and abstracting up to 25Ml/d of river water, allowing for losses in the treatment process and the natural environment, at Longham Lakes to supply Alderney Water Treatment Works (WTW).

The solution proposes to recycle treated water from the existing Poole Water Recycling Centre (WRC) at a proposed new WRC at Corfe Mullen which will use advanced treatment technology. The water will be transferred to the new WRC by a new high lift pump station (HLPS) where flow will be buffered in large storage tanks, before being passed through a series of advanced membranes, adsorption and chemical free disinfection technologies.

Once further treatment is complete, a pump station will convey flow to the River Stour through two new rising mains and outfalls:

The recycled water discharged into the River Stour will flow downstream to the existing Longham Lakes abstraction point where new infrastructure will abstract and transfer the additional water into the lakes where it will be re-abstracted, treated at Alderney Water Treatment Works and released into Bournemouth Water’s existing supply system.

The project is expected to be operational in 2035, providing a maximum peak yield of 25 Ml/d, with an annual average water available for use benefit of up to 12.5 Ml/d to the Bournemouth Water Resource Zone.

RAPID’s final decision has now confirmed that the solution should be funded to progress through the gated process to gate C.

After engagement with the solution owners RAPID has agreed to increase the gate C allowance to £17.938 million and the reprofiling of the gate D allowance to £11.113 million.

Cost estimates for the Poole Water Recycling and Transfer solution have increased significantly since gate two, from £165.18 million to £286.90 million, representing an increase of approximately 74%.

Most of this increase is attributed to the introduction of a new Water Recycling Centre, updated development and indirect costs, and higher risk allowances reflecting improved understanding of construction and environmental risks.

South West Water and Wessex Water have proposed a date for gate four of November 2027 (noting the gate three submission was made prior to the transition to the new RAPID gated process). This was proposed alongside their Town and Country Planning Act application to be submitted in July 2027. The solution would be construction ready in May 2030, and operational in 2035.

Wessex Water has proposed a gate C date of 22 November 2027 in its representation which RAPID has accepted.

Click here to download the decision document in full.