Hampshire Water Transfer and Water Recycling Project

We’re planning to introduce a Water Recycling Plant in Havant, Hampshire, and a new water transfer pipeline to provide a new source of water for our customers in Hampshire during a drought.

Why does Hampshire need water recycling?

We rely on the precious chalk streams and their associated aquifers of the River Test and the River Itchen, to provide the majority of water to our customers in Hampshire. However, we need to find new sustainable sources of water to help keep taps and rivers flowing, following reductions in the amount of water we can take from the River Test and River Itchen. This need is amplified by the pressures of a growing population and changing climate.


Our Water Recycling Plant

Our proposed plant will take some treated wastewater from our Budds Farm Wastewater Treatment Works and purify it further using tried and tested advanced water recycling techniques. After purification the treated recycled water would be pumped into Havant Thicket Reservoir, the first reservoir to be built in the South East since the 1970s which we’re delivering in collaboration with Portsmouth Water.


The new pipeline

We’re also proposing to build a new water transfer pipeline which will take water from the reservoir to our Otterbourne Water Supply Works where it will be treated to drinking water standards and supplied to our customers in Hampshire.

Map of our proposed Water Recycling Plant and Water Transfer Pipeline

Just like water across the country has its own distinct taste influenced by the geology of the local area, the water taken from the reservoir may taste different from existing supplies due to the change in source. The reservoir whilst open to the environment (soil, plants, wildlife) may also influence a change in taste from existing supplies. This water will, of course, continue to meet strict drinking water quality standards and be wholesome to drink. We’re working with a range of international experts, our regulators and environmental organisations to develop our plans.

These proposals are separate to the current approved plans for Havant Thicket Reservoir and if they are to go ahead, they will be subject to further engagement, consultation and planning consent. This is just one of our strategic solutions we're exploring to address water shortages in Hampshire.


Date Milestone
2019 Water Resources Management Plan published
2021 First public consultation on preferred strategy (desalination)
Summer 2022 Public consultation (pipeline route options)
2024 Public consultation (further technical detail on pipeline route and water recycling infrastructure)
2024 Anticipated consent application submission
2026 Consent application decision
2026 Construction starts
2030 Strategic Resource Option operational

Will water recycling be used just in a drought or more regularly?

The Hampshire Water Transfer and Water Recycling Project is being developed for use primarily during periods of drought. To ensure the continued availability and cleanliness of the water recycling plant and associated pipelines, a continuous ‘sweetening flow’ of water would be pumped into Havant Thicket Reservoir and then onward to Southern Water’s Otterbourne Water Supply Works for further treatment.

Are you considering the potential environmental impacts of water recycling to the reservoir?

A range of studies and investigations are ongoing as part of the consenting process for the Hampshire Water Transfer and Water Recycling Project. We will prepare a Preliminary Environmental Information Report which will form part of our next stage of public consultation in 2024. This document will report the preliminary findings on any likely significant environmental impacts of the Project based on the information available at the time and is designed to inform consultees’ responses to the next consultation.

We will continue to undertake environmental assessments and the main Environmental Impact Assessment will be documented in an Environmental Statement that will be submitted as part of the Development Consent Order application.

Environmental commitments made in respect of the reservoir, particularly around the wetland, will be maintained.

Would putting recycled water into the reservoir impact the reservoir design or operation?

The Hampshire Water Transfer and Water Recycling Project is not expected to require any changes to the size or layout of the reservoir as per the planning approval.

Would Southern Water’s proposals impact the potential for community / leisure facilities at Havant Thicket Reservoir?

All of the environmental and community commitments approved in the original planning application for Havant Thicket Reservoir will be maintained if these additional proposals are progressed.

Why not look at storing winter rainfall in aquifers?

Aquifer storage and recovery is where treated water is pumped into an aquifer when surplus water is available to be subsequently abstracted during a drought. It needs the aquifer to be “confined” – where it’s one separate underground body of water where the water would remain.


We’ve investigated this option in Hampshire and do have plans for one such scheme in the Lower Test (where the chalk is confined by London Clay) but it can only provide about 5.5 million litres a day, so much less than the water transfer and water recycling option we’re pursuing. This project is currently forecast for 2040/41.


The issue elsewhere in Hampshire is that the aquifer is unconfined – e.g., the water would simply flow away and could not be guaranteed to remain where it’s put.

Reject stream

Impurities removed from the recycled water will be released back into the Solent via the existing long sea outfall at Budds Farm (5.7km out to sea). This is called the reject stream and will mix with the remaining treated wastewater from Budds Farm. As the source water for water recycling is treated wastewater, there will be no increase in impurities in the reject stream (as these impurities would have already been in the treated wastewater) but they will be more highly concentrated. We are modelling the reject stream quality and exploring with the Environment Agency whether this increase in concentration requires any application to amend our current permit for the long sea outfall.

Further information on water recycling

Find out more about the tried and tested advanced treatment process of water recycling, what our customers think and other water recycling proposals across our region.