East Cambridgeshire is at a crossroads. As climate change intensifies and the region’s population grows, the challenge of securing a reliable water supply has become urgent.
A new report commissioned by the East Cambridgeshire District Council, prepared by the Eastern Powerhouse, lays out a bold vision: a network of local agricultural reservoirs, integrated with existing drainage infrastructure, to provide water resilience and unlock sustainable growth for the region.
A pressing challenge
Water security is not a distant concern for East Cambridgeshire. “It is a present and pressing issue that directly affects our ability to grow sustainably and provide the homes, jobs, and environment our communities deserve,” writes Cllr Anna Bailey, Leader of East Cambridgeshire District Council, in the report’s foreword.
The proposal to create a local network of reservoirs is described as “a transformative opportunity” that could turn flood risk into a vital resource by capturing surplus winter flows and storing water for use during dry summer months.
This approach, the report argues, would not only reduce pressure on drainage systems during heavy rainfall but also ensure a steady supply for homes, businesses, and agriculture when it is most needed.
“It creates opportunities to restore wetlands, rewet peat soils, and enhance habitats for wildlife, making our water system part of a wider effort to recover biodiversity,” the report states.
Climate risks and economic stakes
East Cambridgeshire, situated within the South Level of the Fens—the UK’s largest coastal wetland—is highly exposed to climate-related risks. Rising sea levels, more frequent heavy rainfall, higher temperatures, and prolonged droughts threaten the region. The Fens have already experienced damaging events, including the tidal surge of 2013 and the drought of 2018. In 2022, a hot, dry summer caused water shortages.
However, uncertainty over long-term water supply is creating a bottleneck for housing and inward investment, with major developments stalled due to concerns over water scarcity.
The national and regional water challenge
The East of England is one of the most water-stressed areas in the UK. Over-extraction from chalk aquifers and river systems threatens both ecosystems and long-term public supply. The region faces a projected water shortage of 800 million litres per day by 2050—about one third of current use.
Yet, as the report points out, “the problem is not a lack of water,” but rather the capacity to store it and the ability of existing systems to respond dynamically to growth.
Three major rivers—the Nene, the Ouse, and the Cam—deliver substantial excess water during the winter months.
“Significant efforts have to be made in the region to pump excess water out into the North Sea, at great cost to Fenland farmers and taxpayers, only then to restrict water supplies for all users during the summer,” the report explains.
The limits of centralised infrastructure
While major infrastructure projects are in development, such as the proposed new reservoir near Chatteris, these solutions are years away.
The Chatteris reservoir, led by Anglian Water, is projected to cost £2.2 billion and may not be completed before 2036. In the meantime, constrained supply is already halting or delaying new housing developments in Cambridgeshire.
The report criticises the current regulatory system, which is “centred on 5 year price review periods,” for stifling innovation and leaving little room for place-based solutions. “Without reform, the system will continue to act as a brake on regional development,” it warns.
A local solution: agricultural reservoirs
The heart of the report’s proposal is a network of agricultural reservoirs, supported by local farmers and landowners, to supply incremental water demand until major infrastructure is delivered.
There are already over 80 agricultural reservoirs across the district, with just seven farmers holding 5.4 million cubic metres of water in 24 mid-sized reservoirs—equivalent to 10% of the planned capacity at Chatteris.
A recent technical study suggests that seven new mid-sized agricultural reservoirs could store 6 to 7 million cubic metres of water and could be built in under three years at a cost of £2–3 million each. The report highlights the cost-effectiveness: “A network of agricultural reservoirs would cost £4 to £5 per cubic metre of water compared with £40 per cubic metre from Chatteris.”
Each reservoir, at 85% utilisation, could provide water for 7,000 people a year. Combined with demand reduction measures and interim supply from Grafham Water, this could meet projected housing growth over the next 15 years.
Creating a local water market
The development of agricultural reservoirs would also create a new “water market,” stimulating trade in water between farmers and into the local supply network. This would provide additional income for farmers and Internal Drainage Boards (IDBs), helping to stimulate the wider East Cambridgeshire economy. The report calls for public-private finance arrangements to share costs, risks, and rewards.
A new water treatment works at Waterbeach is identified as a key component, with estimated costs ranging from £40 million to over £200 million, depending on scale. The report notes, “This is still a relatively small sum in the context of sustaining the continued growth of Greater Cambridge.”
Reforming regulation and governance
The report is critical of the current regulatory framework, which it describes as fragmented and siloed. It calls for “a system that is more accountable, transparent, and responsive to place-based needs,” including legislative changes to empower IDBs and give local authorities a stronger voice in water planning.
A new Cambridgeshire and Peterborough Water and Growth Board is proposed to coordinate water infrastructure planning and delivery, bringing together water companies, regulators, local authorities, and community representatives.
Conclusion: a call to action
The report concludes that “the water crisis facing the East of England is not only a constraint but an opportunity.”
By piloting new models of local water management, East Cambridgeshire can accelerate delivery and enhance sustainability. The council commits to supporting the development of agricultural reservoirs as part of its corporate strategy to address water scarcity and unlock growth.
The recommendations are clear: continue to promote sustainable water management, support the development of agricultural reservoirs, work with regional partners to fund feasibility studies, and promote this model as a national pilot.
For government, the report urges piloting water market reform, amending legislation to empower IDBs, and expanding the statutory role of local authorities in strategic water planning.
As the report states, “East Cambridgeshire is well-positioned to lead by example, showing how local leadership, when empowered, can drive sustainable transformation.”
All information and quotes sourced from the East Cambridgeshire District Council’s July 2025 report, “A network of local reservoirs: Providing water resilience and security to unlock growth in the region.”
Here are the key benefits of agricultural reservoirs, as outlined in the East Cambridgeshire District Council report:
- Fast delivery: Can be designed, approved, and built within three years.
- Cost-effective: £4–£5 per cubic metre of water, compared to £40 per cubic metre for large-scale reservoirs.
- Flexible and scalable: Can be expanded incrementally to match local housing and employment growth.
- Environmental benefits: Supports peatland rewetting, wetland restoration, and biodiversity; reduces carbon emissions by using gravity-fed systems.
- Improved drought and flood resilience: Stores surplus winter water for use in dry months and reduces flood risk by easing pressure on drainage systems.
- Economic boost: Provides extra income for farmers and Internal Drainage Boards through water trading; supports local agricultural productivity.
- Unlocks housing and development: Ensures a reliable water supply, enabling new homes and jobs.
- Local control and innovation: Empowers local authorities, farmers, and landowners to manage water resources and encourages innovative, place-based solutions.
