The Trust has been involved in reviewing the Havant Thicket Reservoir proposals for several years, including through the Havant Thicket Stakeholder Board. Across Hampshire and the Isle of Wight, we are increasingly concerned about the management of our collective water resources as we see pressures from abstraction and pollution on legally protected and important sites for wildlife, including some of the Trust’s nature reserves and the internationally renowned chalk streams.  

We are concerned that water companies can continue to abstract, including in periods of drought, from our internationally renowned chalk streams such as the River Itchen Special Area of Conservation up until 2040. We urge water companies to accelerate a range of measures to reduce reliance on abstraction from our chalk streams as quickly as possible. However, they must also carefully consider and assess the potential impacts of these proposals on other designed sites including the harbours and the Solent, a legally protected ecosystem which is already under immense pressure due, in part, to the legacy of routinely discharging treated and untreated effluent into our rivers and seas.  

We were encouraged that Southern Water is no longer progressing the Desalination Plant proposal on the Solent, for which we raised serious concerns about the impact the brine discharge would have on wildlife and the designated areas of the Solent. 

We have been made aware of a number of concerns raised by the community regarding the environmental impact of ‘Hampshire Water Transfer and Water Recycling Project’ proposals for Havant Thicket. We therefore seek firm commitments, supported by robust evidence, that the proposals would not adversely impact the River Itchen Special Area of Conservation (SAC) or Chichester and Langstone Harbours Special Protection Area (SPA), the Solent Maritime SAC, the Solent and Southampton Water SPA and Ramsar and, Portsmouth Harbour SPA and Ramsar. 

Reduce reliance on abstraction in our internationally renowned chalk streams 

In principle, the Trust would not object to a solution, such as wastewater recycling, that would reduce reliance on abstracting water from our chalk streams. However, the implementation of measures designed to address this issue, should not come at the expense of unsustainable downstream environmental impacts. 

One of the Trust’s key priorities is to encourage Southern Water and Portsmouth Water to vastly reduce their reliance on abstraction from our chalk streams, especially the designated River Itchen SAC. With climate change increasing the frequency and severity of droughts, we must see the water companies accelerate plans to develop long-term, more sustainable, solutions that rapidly reduce abstraction and eliminate the use of drought permits. 

In particular, we consider that the water companies must reduce reliance on short-term mitigation measures in future and provide better long-term resilience for our internationally important chalk streams. It's vital that the water companies secure an alternative water supply as soon as possible to protect the River Itchen, yet the draft Water Resource Management Plan for 2024 outlines that no additional large scale water resource solutions will be available until early 2030. We would like to reemphasise that under Section 20, Southern Water are legally required to use all best endeavours to find an alternate water resource.    

We must strongly reiterate the importance of water efficiency measures, reducing leakage of supply pipes, water recycling and bulk water transfers to ensure that abstraction to a potentially damagingly low HOF level is truly a last resort measure, not routine.  

Impacts to our legally protected harbours in the Solent 

Currently, we do not consider that Southern Water has assessed the environmental impact of the ‘Hampshire Water Transfer and Water Recycling Project’ on the designated Solent Marine Sites. In particular, we urge Southern Water to provide more information, including a Habitats Regulations Assessment (HRA), on what will be directly discharged into the Solent as a result of this project and the potential impacts on the designated sites.  

In particular, we seek confirmation that the net benefit of the Havant Thicket reservoir on nutrients in the designated harbours will be maintained. We would like to see accurate detail of the potential increase in inputs through the Lavant and Hermitage Stream and also the volumes and composition of the outputs through the long sea outfall.   

Considering the significant public concern, we urge this information to be provided in time for a robust consultation on the proposals in the summer.  

Impacts on the ecosystems at Havant Thicket reservoir  

During the initial proposal and consultation for Havant Thicket reservoir, we were pleased to see the creation of new wildlife habitats integrated into the reservoir design. The wildflower-rich outer slopes would create much-needed pollen and nectar for insects and the wetland is probably the main feature of interest from an ecological point of view within the locale of the reservoir.  

Furthermore, technical analysis from Natural Capital Solutions suggests that there is a large increase in the ecosystem services benefits that may be derived from the reservoir project worth approximately £2,243,667 annually in a normal year, rising to £4,913,467 annually in a drought year. 

We need to see clear evidence provided by Southern Water and Portsmouth Water that the water recycling proposals for Havant Thicket will not undermine the net gain for wildlife or the ecosystem services provided by the project.  

Tackle sewage issues and provide robust ecological evidence on impacts to build trust 

It is of the utmost importance that the proposals for the ‘Hampshire Water Transfer and Water Recycling Project’ are correctly scrutinised to ensure it doesn’t have an adverse impact on the designated sites and provides a sustainable long-term solution to abstraction from our chalk streams. This necessitates additional engagement and scrutiny beyond what has taken place so far. 

As a whole, we consider that Southern Water’s efforts so far haven’t been sufficient in tackling water quality and supply issues, considering that the most recent Environment Agency water and sewage companies environmental report found Southern Water to be performing significantly below target on security of water supply, the worst performing company in the country. This has ultimately led to an understandable level of skepticism within the local community regarding Southern Water’s ability to deliver these wastewater recycling plans without adverse ecological impacts on highly designated sites.  

The Trust is clear that water recycling could be an essential component of a suite of measures needed to help us reduce reliance on chalk streams, if accompanied by robust ecological analysis. We must urgently see robust evidence that the proposals would not adversely impact any legally protected habitats, including the Chichester and Langstone Harbours Special Protection Area (SPA), the Solent Maritime SAC, the Solent and Southampton Water SPA and Ramsar and, Portsmouth Harbour SPA and Ramsar. 

We would urge Southern Water to rapidly addresses some of the shortcomings in the information provided to support this application and to bring forward parallel plans to address issues around sewage and water quality in the Solent, for example through reducing reliance on storm overflows.  Without robust and credible plans to address the wider environmental impacts of their operations Southern Water will struggle to be seen as a Trusted deliverer of schemes of this kind.