Market engagement opens for Southern Water’s £1.3bn Hampshire water transfer & recycling project

Southern Water Services Limited has opened a new preliminary market engagement process for the Hampshire Water Transfer and Water Recycling Project (HWTWRP), one of its most significant proposed infrastructure schemes. The notice represents what is expected to be the final round of market engagement ahead of a formal tender planned for early 2027. The project carries an estimated value of around £1.3 billion.

The HWTWRP is a designated Strategic Resource Option and forms a central element of Southern Water’s long-term strategy to address projected water supply shortfalls in Hampshire. The scheme is designed to optimise the use of the Havant Thicket Reservoir’s 8.7 billion litres of storage capacity, creating a new, resilient source of drinking water for the region.

The proposed development. Credit: Southern Water.

At the core of the scheme is an integrated system in which treated wastewater, which would otherwise be discharged offshore, is converted into purified recycled water and stored within Havant Thicket Reservoir. Water from the reservoir will then be transferred to the existing Otterbourne Water Supply Works for further treatment before entering supply. During periods of increased demand or drought, the scheme could provide up to around 90 million litres of water per day into the Hampshire supply network.

The scope of the project is extensive and technically complex. It includes a new water recycling plant, tunnelling and pipeline connections, a high-lift pumping station and approximately 42 km of transfer infrastructure, including intermediate pumping stations and break pressure tanks. Delivery will be through a Design, Build, Finance, Maintain and Operate (DBFMO) model.

Procurement will follow Ofwat’s Direct Procurement for Customers framework, with Southern Water planning an open competition to appoint a Competitively Appointed Provider responsible for delivering and operating the assets over an estimated contract period from August 2029 to March 2059.

The current engagement phase invites input from investors, contractors, operators and potential consortia. Engagement activities include a market survey, a Request for Information, a townhall event scheduled for April 2026 and a limited number of bilateral meetings. Interested parties are required to register via Southern Water’s Jaggaer One portal, through which all updates and documentation will be issued.