Q&A
- Following us on social media via our reservoir Facebook page(External link)(External link) or updates on X(External link)(External link)
- Sign up for our regular e-newsletter(External link)(External link).
What is the plan for a new reservoir?
We are planning to invest £340 million to build a new reservoir in Havant, Hampshire. It is being built in collaboration with Southern Water and will help secure more reliable and resilient water resources for our area and the wider South East.
Why is it needed?
The South East, as a whole, is under ‘serious water stress’ and water companies are being asked to take less water from some of their sources – such as the chalk rivers in Hampshire – to keep them healthy and protect wildlife.
At the same time, water companies need to find more water to cater for the effects of climate change and a growing population.
This major change is going to particularly affect Southern Water, which needs to find new water resources for the customers it supplies drinking water to in Hampshire, to replace water taken currently from the River Test and the Itchen.
In Portsmouth Water's area, there are underground springs which provide plentiful, clean water. In winter, much of this water is surplus to requirements and flows out to sea, so we could make better use of some of it by capturing it and storing it in the reservoir until it’s needed.
This will allow us to share more water with Southern Water’s customers in Hampshire from our network and increase the resilience of water supplies in the South East.
We already have agreements to share up to 30 million litres of water a day with Southern Water (in West Sussex and Hampshire).
We can share a further nine million litres a day from 2024 from other sources (Hampshire)
We can provide an extra transfer from a mix of sources when the reservoir is built, up to 21 million litres a day (to Hampshire)
The total would be up to 60 million litres of water per day provided to Southern Water.
Overall, building the reservoir would make the whole South East much more resilient to droughts, which are likely to happen more often in the future due to climate change.
How much water will it hold?
The reservoir will be able to hold about 8.7 billion litres of water when full and supply an average of 21 million litres of water each day.
That’s enough water to supply about 160,000 people during an average year.
What will the reservoir offer to Portsmouth Water customers?
As well as being supplied with water from the reservoir, our customers will have the benefit of a new community leisure facility on their doorstep. There will also be a host of environmental benefits locally.
The reservoir site will create a new, healthy and safe place for people to visit – with footpaths for walking, as well as routes for cycling and horse riding, facilities for bird watching, picnic and play areas and car parking.
There will be a visitor centre with a café, toilets and space for community and education activities.
Our proposals for the site so far have been developed over many years with local communities, young people and organisations such as Staunton Country Park and Forestry England.
What will the reservoir offer to Southern Water’s customers?
Building the reservoir will allow us to share water supplies with households in Hampshire (outside of our supply area) who receive their drinking water from Southern Water and where there is a severe shortage.
This means Southern Water’s customers will have reliable water supplies and less water will need to be taken from the River Test and River Itchen, which will be better for the environment.
Our customers in Hampshire who we supply water to are also customers of Southern Water for their wastewater services, so everyone in the area will benefit from the community and leisure facilities at the reservoir.
What will the reservoir look like?
The reservoir will be about one mile (1.6 km) long from east to west and 0.5 miles (0.8 km) wide from north to south. It will be up to 18 metres deep and have embankments on three sides. The below image shows what the reservoir could look like when completed and open to the public.
What activities will be on the site?
We’re planning to build a visitor centre on the site with a café, toilets and space for education and community activities.
There will also be footpaths for walking, cycling and horse riding, facilities for bird watching, such as bird hides, and picnic and play areas. Furthermore, there will be car parking and cycle racks.
We’re working in partnership with neighbouring Staunton Country Park and Forestry England, organisations we already work very closely with, to make sure the facilities and activities are a good fit with theirs.
What about the environment and wildlife on the site?
Our approach to designing the reservoir has the environment and the community at its heart. Further details are set out below.
Our masterplan covers all the environmental and community factors we are taking into account. This means we’ve considered the environment as we’ve designed every part of the reservoir, the access roads and pipeline, and we’ll continue to do so.
We’re also working closely with Forestry England, who own and look after the neighbouring Havant Thicket woodland, and Staunton Country Park (which is owned and run by Hampshire County Council) to see how we can manage the sites together in the future.
This approach, along with lots of feedback from local communities and environmental organisations, has helped us choose the facilities we’re offering, namely:
- A wetland habitat to support threatened bird species and provide areas for endangered bat species to find food
- A visitor centre with a café and facilities for communities and schools
- A network of trails and paths for walking, cycling and horse riding, linking to others in the wider area
- New woodland, hedgerows and wildflower planting
- A landscaped parking area for vehicles and bicycles.
The reservoir project will improve existing woodland and create a valuable new wetland, woodland and parkland. A grant scheme will also support wildlife across Hampshire and West Sussex.
Creating the reservoir will help protect the River Test and River Itchen in Hampshire. By using the reservoir to supply our own customers, we can share supplies from our other water sources with Southern Water. This means they will be able to reduce the amount of water that they take from these rare and sensitive chalk streams, which are home to many species.
We needed to remove 12.5 hectares of ancient woodland to build the reservoir and we reduced this as much as possible by changing the design. We’re committed to replanting and improving around 200 hectares of woodland and pasture both on and around the site and further afield to leave an overall positive gain for the environment and communities.
How are you involving residents and communities and other organisations?
As well as securing drinking water supplies and creating new homes for wildlife, the reservoir has the potential to become a new leisure and community focus point for Havant.
We’ve been working hard to involve the local community in every stage of this exciting opportunity, such as the public consultation we ran during May and June 2020. During this, hundreds of people were able to find out about our updated plans and have their say – feedback that helped shape the planning applications we submitted to Havant Borough Council and East Hampshire District Council.
In August 2020, we published our ‘You said, we did’ report(External link)(External link), summarising what people told us during the consultation and how we’re responding to the points raised. The reservoir planning application documents are available to view on the councils’ planning web-pages, plus you can download our Havant Thicket Reservoir Design & Access Statement.
Our plans also continue to be shaped by the 70+ members of our Havant Thicket Reservoir Stakeholder Advisory Group, which was established in 2004. The group is made up of representatives from a range of organisations, including local councillors and community and environmental groups. You can view the presentations and minutes from the regular stakeholder group meetings via our Library page.
As well as visiting this website, you can stay in touch with the reservoir project’s progress in the following ways
Get in touch if you’d like to find out more or be involved.
Schools and education
The reservoir project offers fantastic opportunities for education locally – not only when the reservoir is complete, but also during the planning and construction stages.
Local pupils have been involved since the start of the project, with local young people providing feedback during both our 2008 and 2020 public consultations.
And as the reservoir progresses, the reservoir will become a great venue to learn about the water cycle, climate change, the environment and wildlife, and STEM subjects (Science, Technology, Engineering and Maths).
We’re also involving young people in our environment work to grow and plant trees and hedgerows.
When built, school parties will be welcome at the reservoir to use the education space, bird hides, interpretation boards and the leisure facilities.
How can I find out more?
There’s lots more information on this website, where you can also give us your questions and comments using the 'Ask us a question' tool on each page.
You can also get in touch with us via email, phone or post. See our Get in touch page for more.