World-famous, globally rare and extraordinarily biodiverse, the Wessex chalk streams are irreplaceable, relying on a steady, crystal-clear aquifer-fed flow of water.
Our chalk streams are facing a water crisis. With the demands of a growing human population and increasingly extreme weather patterns, river flows are becoming less reliable. The summer of 2019 saw some chalk streams in the South East run completely dry, which should flow year round, sounding the alarm for chalk rivers of the Wessex region.
Plans have been drawn up to improve the water situation in Southern Water’s (Hampshire) Western Area. These include the construction of Havant Thickett reservoir, and setting up water transfer schemes. It will take 10 years or more for new sources of water to be up and running and drought permits are expected to be needed to allow abstractions to continue during the next decade until the permanent new supply schemes are in place. Until then, Southern Water are legally obliged to bridge this gap with works to mitigate against the potential impact on chalk stream reaches likely affected by drought permit abstraction.
Southern Water are also legally obliged to provide habitat compensation by improving the quality and flow resilience of sections of chalk stream not directly impacted by drought permits (but nonetheless vulnerable to climatic low flow events). This compensation package amounts to one of the largest investments in the water environment in a decade; an unprecedented sum of money for the rivers of Southern England. Wessex Rivers Trust will lead on the delivery of this compensation work via the FReSH (Flow Resilient Sustainable Habitat) Water Programme.
The FReSH Water Programme is an ambitious, multi-year effort to improve the resilience of Hampshire’s chalk streams in the face of drought, climate change, and water quality pressures. By restoring natural processes and habitats, the programme aims to return to rivers the ability to regulate themselves through high- and low-flow conditions, improving the long-term ecological performance of these globally rare ecosystems.
Wessex Rivers Trust brings a joined-up, catchment-scale approach to this work. Because the Trust is already active across Hampshire’s river systems, we can connect FReSH delivery with existing restoration programmes, local priorities, and long-term management. Ensuring each site contributes to wider river recovery, not just isolated improvements.
In late 2019, Southern Water approached Wessex Rivers Trust to take on the role of lead delivery partner for the compensatory river habitat improvements required under the Section 20 Agreement. After careful assessment, including legal advice, the Trust agreed for two key reasons:
• The programme represented a rare opportunity to deliver transformational, landscape-scale environmental improvement for Hampshire’s chalk streams
• As an independent charity with specialist expertise, Wessex Rivers Trust was best placed to ensure the programme remained focused on environmental outcomes rather than commercial interests
Early conversations with landowners and fisheries managers showed strong appetite for positive, practical restoration and their input and cooperation has been vital to the development of the project. From the start, the Trust ensured that the programme would operate with full independence and appropriate governance. The Environment Agency, supported by Natural England, continues to act as the relevant authority, assessing and approving all project plans and delivered works to ensure they meet the requirements of the Section 20 Agreement. Southern Water’s role is solely to provide the funding that enables the delivery of the programme.
Now five years into delivery, the programme is already showing significant progress. Restoration projects have been delivered at more than 20 sites to date, spanning several kilometres of river habitat. Restored and reconnected habitats are already supporting improved river function and biodiversity, and interventions made at individual sites are beginning to interact and strengthen one another at a catchment scale, an exciting sign that long-term resilience is building as intended. These successes reflect close collaboration with landowners across the catchments, many of whom have gone above and beyond to support access and steward works after construction.
The next phase of the programme will continue to expand delivery, monitor ecological outcomes, and embed the benefits of restoration so that Hampshire’s chalk streams are better prepared for the pressures ahead.
The programme focuses on stretches of the River Test (Kimbridge to Wherwell), River Dever, River Dun, Bourne Rivulet, River Meon, and potentially the Dorset Stour. These are not directly impacted by drought permit abstractions but share ecological characteristics with affected areas, making them suitable for compensatory improvements.
Mitigation: Works on rivers directly affected by abstraction to reduce the immediate impacts of drought. This is delivered by the Environment Agency, Southern Water, and partner organisations.
Compensation: Works on rivers not directly affected, designed to offset potential impacts of drought abstraction elsewhere. FReSH focuses on compensatory habitat improvements, enhancing river ecology and benefiting priority species.
Site-specific interventions may include:
• Improving fish habitat, including fish passage and spawning areas
• Enhancing weed and wetland plant communities
• Diversifying flow patterns to improve habitat quality
• Reprofiling channels to support low-flow conditions
• Supporting invertebrates and other wildlife
• Maintaining recreational and angling opportunities
Sites are chosen based on the ecological benefit to priority habitats and species, informed by baseline surveys, historic data, and the expertise of the Trust and partners. Public access may be considered but ecological benefit is the primary driver.
Wessex Rivers Trust leads compensatory habitat improvements, working with landowners, fisheries managers, and partners such as the Environment Agency and Hampshire & Isle of Wight Wildlife Trust. Southern Water provides funding, while regulatory oversight ensures all projects meet legal and ecological requirements.
The programme focuses on chalk stream habitats and the species associated with them.
Ecological monitoring and habitat surveys will track improvements in river connectivity, species abundance, and habitat diversity. All projects are approved and monitored by the Environment Agency and Natural England to ensure objectives are met.
FReSH complements other initiatives, including the Watercress & Winterbournes project. Collaboration allows resources and expertise to be shared, maximising benefits for rivers and wildlife.
We work with a wide range of landowners and river managers, including estates, farms, fisheries, private landowners, and local councils. Engagement is coordinated with statutory partners to ensure a collaborative approach.
