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Havant Thicket Reservoir

Havant Thicket Reservoir – Briefing Note

Latest 2019 Newsletter     [see below for previous Newsletter and map]

What is the plan for a new reservoir?

We’re planning to invest more than £100 million to build a new reservoir in Havant, Hampshire. It’s being built in collaboration with Southern Water and will help secure more reliable and resilient water resources for the wider South East. The reservoir will be able to hold about 8,700 million litres of water when full and supply up to 21 million litres of water each day. That’s enough water to supply about 160,000 people during an average year.

Water from the reservoir will be used to supply Portsmouth Water’s customers in and around the Havant area. This means that water from our existing source on the River Itchen at Gaters Mill, and other local sources, can be transferred to Southern Water, providing additional supplies to its
customers in other parts of Hampshire.

Why is the reservoir 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. This includes reductions to the amount of water that Southern Water can take from the rivers Test and Itchen in Hampshire. To address this, and cater for the effects of climate change and a growing population, new sources of water are needed, alongside sustained reductions in leakage and water use.

Havant Thicket reservoir is included in the water resource management plans of both Portsmouth Water and Southern Water and was identified through the regional modelling carried out by Water Resources South East. It will provide an important, strategic resource to help secure supplies, protect the environment and increase the resilience of this part of the region.

Portsmouth Water is in a unique resource position due to the underground springs which provide plentiful, clean water. In winter, much of this water is surplus to requirements and flows out to sea. The scheme will allow us to capture this water and store it in the reservoir until it’s needed.

How much water will be transferred once the reservoir is operational?

We are already transferring up to 30 million litres of water each day to Southern Water. Once the reservoir is operational in 2029 this will have doubled to 60 million litres of water per day – through an additional 9Ml/d from existing sources and up to 21 million litres of water per day enabled by the reservoir. In total this is enough to supply a city the size of Manchester. This means that more than a quarter of the water we produce will be transferred to others.

Where will it be built?

The reservoir is planned for a 160-hectare site in Havant, which has been owned by Portsmouth Water since 1965. The site is next to Rowlands Castle, Leigh Park and Warren Park. It is bordered by the Havant Thicket woodland to the north owned by Forestry England and Staunton Country Park to the south, which is owned by Hampshire County Council. It is currently made up of grazed grassland with small areas of trees and paths. A new pipeline will be constructed to transfer water from the Havant and Bedhampton springs to fill the reservoir.

The environment and natural capital

Overall, building the reservoir will bring more benefits – for the environment, wildlife and local people – than the existing grassland and trees. The Hampshire and Isle of Wight Wildlife Trust commissioned a Natural Capital assessment of the project. It estimates that the reservoir will deliver additional ecosystem benefits with a present value of £57.26 million (over 50 years) with greater values associated with drought years (£125.40 PV over 50 years).

It is our intention to deliver a net-gain for the environment by:

• creating new woodlands and hedgerows
• improving existing woodlands next to the reservoir
• creating a large wetland to support a range of wildlife, including nesting birds
• planting wildflowers on the reservoir banks
• setting up a grant scheme to support biodiversity projects further afield.

Work to create new woodland on site has already started with hundreds of trees and hedgerows planted in 2019 – to create a woodland corridor. Four small blocks of woodland on the existing site, which are designated as ancient woodland by Natural England, will need to be removed so we have worked closely with Natural England, Forestry England, Hampshire County Council, the Environment Agency, local planning authorities and wildlife trusts to develop plans to offset this. Extensive surveys have already been carried out to look for and monitor wildlife such as dormice and bats and new habitats will be established for wildlife to migrate to before work to build the reservoir begins.

Community and societal benefits

As well as being supplied with water from the reservoir, our customers will have the benefit of a new, community leisure and environmental facility on their doorstep. The reservoir site will create a new, healthy and safe place for people to visit – with footpaths for walking, cycling and horse riding, facilities for bird watching, picnic and play areas and car parking. There could also be a visitor centre with a café, toilets and space for community and education activities. The exact facilities will be outlined in a planning application, following engagement with local communities. This is due to be submitted to Havant Borough Council in late 2020.

How much will the reservoir cost and who will pay for it?

It will cost about £100 million to plan, build and fill the reservoir with water.

Our joint proposal with Southern Water is that the scheme will be funded by payments from them to purchase the water they need to supply their customers. (Southern Water has considered a number of options to supply water to its customers and the reservoir is considered to be good value). Only Southern Water customers who receive drinking water supplies from Southern Water will have the cost of the reservoir reflected in their bills. So, this does not include our customers who receive drinking water from Portsmouth Water and wastewater services from Southern Water.

When will it happen?

We plan to submit a planning application for the reservoir to Havant Borough Council and East Hampshire District Council in late 2020. If the planning application is successful, we will begin preparatory work on site in 2021-22 and start construction of the reservoir in 2023. The reservoir is planned to be operational by 2029.

How are you involving local residents and communities and other organisations?

The reservoir has been the subject of extensive consultation and engagement since its was originally put forward in 2008. The local community was involved in choosing the shape and size of the reservoir. the access route, the pipeline route and the type of activities which would be provided. We also worked closely with the local councils, Staunton Country Park, Forestry England and organisations like Natural England, the Environment Agency and the Hampshire and Isle of Wight Wildlife Trust. This has included a dedicated Havant Thicket Stakeholder Group, which has been meeting since 2004.

We’re building on this engagement and we’ll be sharing more information through the website, parish and local council newsletters and websites, giving talks, holding site tours and sharing our progress through the media and social media channels. We’ll also be talking to lots of residents around the reservoir site to hear their views, find out the best way to share more information and involve local communities in the project.

We’re meeting regularly with council representatives, environmental groups, MPs, business groups and other interested parties, as we prepare the detailed planning application to submit in late 2020. Feedback on our Water Resources Management Plan showed a high level of support for the reservoir. 87% of people supported our plans to build Havant Thicket and 80% supported our plans to share water with Southern Water.

Contact details

For more information about the scheme please contact: Simon Hughes, Stakeholder and Environment Lead simon.hughes@portsmouthwater.co.uk. You can also follow progress online at portsmouthwater.co.uk/havant-thicket-reservoir and through our social media channels Facebook @havantreservoir or on Twitter @PortsmouthWater.

Previous Newsletter

In August 2014 Portsmouth Water published its Final Water Resources Management Plan. While the reservoir is not included in the current plan, it remains a feasible option for the future. The Company Plan is under regular review and a number of factors could change which would trigger the need for the reservoir. As a result the timescale for the reservoir remains uncertain, but the reservoir option could be brought forward at any time.

Portsmouth Water will continue to work with the Water Resources in the South East Group (which comprises the Environment Agency and all water companies in the SE) to promote the benefits of the Havant Thicket Reservoir as a potential new regional water resource and green infrastructure site. The Company believe that the reservoir remains a key part of a potential solution to water resource demand issues in the south east, especially as the water used to fill the reservoir would be supplied from an existing sustainable source (Havant and Bedhampton Springs), which already complies with the Habitat Regulation requirements.

It will have sloping embankments to three sides and include a wetland area to the north for birds and wildlife.

The plan shows how the amenities may look around the site.

Take a helicopter tour to see what the reservoir might look like.