Earthworks Trials for the Fens Reservoir
Anglian Water and Cambridge Water are proposing to undertake temporary earthworks trials to help inform the construction methods and detailed design of our proposed new reservoir in the Fens.
The works will build on what we have already learned through our modelling and other ground investigations, testing designs and construction methods in real conditions. This will help us further our understanding of the most effective ways to build the reservoir embankment, including how the clay should be handled and compacted, what construction methods work best, and how quickly the work can be carried out.
The proposed earthworks trials include a trial embankment, together with the temporary features needed to construct and monitor it, including a borrow pit (where we would dig out the clay we require), water management areas and construction working areas.
The works would be temporary and would be deconstructed once they are complete.
We will be consulting on the Earthworks Trials in the autumn, when we will update this page with more information about what we are proposing and how you can have your say.
Frequently asked questions
What is the planning process for the earthworks trials?
The earthworks trials require their own planning permission from Fenland District Council. This is separate from our future Development Consent Order (DCO) application for the Fens Reservoir project, which we plan to submit to the Planning Inspectorate in 2028. The planning permission would be temporary and the works would be deconstructed once they are complete.
Will I get to have a say on the proposals for the Earthworks Trials?
Yes. We will be having a 21 day consultation on the Earthworks Trials, including an in-person event, where you will be able to find out more and provide feedback. We will update our website with full details when the consultation launches.
What is a trial embankment?
The trial embankment would be a test, a temporary piece of embankment that we would build to inform our construction methods and detailed design. Because it's a test, it will not look like the main embankments we're proposing for the reservoir. It will be smaller and steeper, and will not have grass or trees on it.
Constructing a trial embankment will allow us to:
- Model soil behaviour and monitor settlement over time
- Validate design parameters and construction techniques
- Assess risks and refine our overall construction programme
- Improve our understanding of on-site material. We expect this could lead to a more efficient, safer and cost-effective construction programme
As with all parts of the Earthworks Trials, the trial embankment will be deconstructed once the trials are complete.
Why are we proposing a trial embankment as part of the earthworks trials?
Building a trial embankment would allow our engineers to test construction techniques and understand how the ground and materials behave under realistic conditions.
It would help us further our understanding of how local soils behave and settle over time, test how materials can be compacted and placed, confirm and refine important design information, identify and manage potential construction risks, and improve our understanding of how the reservoir could be built efficiently and safely.
The work would be closely monitored, including measurements of settlement and water pressure within the ground. We would also carry out clay compaction testing to understand the most suitable methods for using materials.
Doing this work at an early stage will help us make more informed decisions about the design and construction programme and reduce uncertainty before construction of the reservoir itself begins.
Find out more
Latest project news
We'll be providing regular updates about our proposals for a new reservoir in the Fens as they progress here.
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FAQs
Read our frequently asked questions for more information about the project, what we're proposing and what it could mean for you.