A new public water supply reservoir for the Fens

Today’s blog is written by Daniel Pullan, our Senior Conservation Officer for Cambridgeshire, Bedfordshire and Hertfordshire, on the opportunities for nature in the proposed Fens Reservoir.  

Anglian Water are proposing a new public water supply reservoir in the Fens. The RSPB wants your support to make sure that this once in a generation opportunity protects and enhances the area’s wonderful wetlands for people and for nature.  Please read to the end to find out how you can help by commenting on plans for this new Cambridgeshire located reservoir by the 21 December 2022 when the consultation closes. 

On 10 October, Anglian Water opened up their first public consultation on a proposed new public water supply reservoir at their preferred site near Chatteris, Cambridgeshire. 

The proposal is for a Grafham Water-sized reservoir, along with a sister reservoir project in Lincolnshire. If they go ahead, these will be the first public water supply reservoirs built in England for over 30 years. 

They are being proposed to meet the urgent need for more drinking water in the region. This demand is from an increasing population, along with an urgent need to reduce groundwater abstraction which is adversely affecting the region’s internationally important chalk streams. 

We have first-hand experience of this at our RSPB Fowlmere Reserve south of Cambridge, which holds the headwater springs of the River Shep. These springs would go dry most summers if the Environment Agency didn’t provide mitigatory groundwater pumping to keep the river flowing. However, this is often not enough to also keep our reserve wet, leading to a number of summers recently where our reedbeds, pools and swamps have gone dry. This situation is exacerbated by groundwater abstraction for public water supply in the area which depletes the aquifer. 

A nature opportunity in the Fens? 

The preferred reservoir site is not too far away from our RSPB Ouse Washes Reserve. This man-made washland stretches for nearly 21 miles across the Cambridgeshire Fens and its seasonally flooded wet grassland habitat holds internationally important populations of breeding waders such as black-tailed godwit and snipe. However, for the last 30 years, they have increasingly suffered from late spring flooding which drowns their nests and has led to rapidly decreasing populations. 

Snipe - Andy Hay/RSPB-Images

The new reservoir would take the majority of its supply out of the Great Ouse River system in the winter. But it could be designed so that it also takes water reactively out of the river system in the spring, so reducing the chances of flooding and safeguarding wader nests. If possible, this would be an amazing conservation success, and a real ‘silver bullet’ to an intractable problem. 

At the same time though, we will be working hard to ensure that the Ouse Washes is not threatened by the possibility of using the reserve for ‘emergency drawdown’ where water might be dumped onto the washlands in the unlikely event of a problem. 

The reservoir project might also provide other significant nature benefits. There is the possibility of new wetland habitats both as part of the reservoir, but potentially also off-site. If designed well, these could provide an important haven for some of the Fens’ iconic species and provide ‘stepping-stones’ to help connect existing wetlands in the area. 

Local well-being 

The reservoir could be designed to become a really fantastic destination for local Fens communities. Despite being surrounded by farmland, there are limited opportunities for local people to enjoy the great outdoors and experience nature first-hand. With appropriate infrastructure, the new site could connect local people with wet nature and provide a really important resource to bolster physical and mental well-being. 

Carbon 

As much of the Fens was wetland before it was drained for agriculture, its soils hold significant residual amounts of peat. The oxidation and erosion of this peat leads to significant carbon dioxide emissions from the Fens every year. It will be important that the project treats any peat on the site properly so it is not lost. It’s also really important that the construction and operation of such a large bit of infrastructure is done in the most carbon-efficient way possible, so we will be pressing for this as well. 

The RSPB sees the proposed Fens Reservoir as a significant opportunity for nature. We will be working with Anglian Water along with our partners to try and get the best result for wildlife. 

How can you help? 

If you are local to Cambridgeshire you can help us. We need you to comment on Anglian Water's public consultation for the design concept of the reservoir by 21 December 2022, and we've given you some step-by-step guidance on how to do that and guidance on responses below: 

• Click on https://www.fensreservoir.co.uk/our-proposals/our-proposed-site/ to access Anglian Water’s consultation page. 
• Go to the ‘The proposed site area – section 1 of 4’ column on the right-hand side 
• Question 1: Please fill in if you wish to. 
• Question 2: Please fill in if you wish to. 
• Question 3: Please indicate in your own words that the reservoir must not threaten the Ouse Washes as an emergency draw-down destination, with the possibility of water being dumped on to the washland during the breeding season. 
• Question 4: Please indicate in your own words that you want to see the reservoir help stop spring flooding on the Ouse Washes by taking water out of the river that might otherwise drown wader nests during the breeding season.  
• Question 5: Please fill in if you wish to. 
• Click ‘Add my feedback +’ box at bottom of this column to save your answers so far. A box will appear stating ‘View Your Progress’ See your feedback progress here. Ready to submit your feedback? Click Review feedback’. Click on Close. 
• Scroll down the page looking at left hand column for a box that says, ‘What the reservoir could deliver’. Click on that box to move to page 2. 
• On page 2, move to ‘Designs and features’ Section 2 of 4’ column on right hand side. 
• Question 6: Please indicate in our own words, the following two points:  
• That you would like to see new wetland habitats created on and off the reservoir that benefit nature and the breeding bird populations for which the Fens are important. 
• That you want the reservoir to be designed so that local people have a great place for outdoor recreation and contact with nature.  
• Question 7 please tick what you think is important, but include ‘wildlife enhancement and conservation’, ‘ecological enhancements’, ‘education facilities’ and ‘creating a recognised visitor destination’.  
• Click on ‘Add to my feedback +’ to save your responses. 
• Scroll down looking at left hand column. Click on ‘Consultation overview’ to go to page 3. 
• Move to right hand column, ‘General’ Section 3 of 4. 
• Question 8: Please indicate that the construction and operation of the reservoir must conserve peat soils and reduce carbon emissions to the minimum. Underneath that move to the ‘Consultation’ Section 4 of 4 section of the right-hand column. 
• Question 9: Please tick ‘notified by someone else’ as you were likely notified by us about this consultation 
• Question 10: Please comment if you wish to. 
• Question 11: Please comment if you wish to. 
• You have completed the four sections of feedback. 
• Click on the green ‘Feedback progress – 4/4 sections completed’ – Review Feedback’ button. A Review Your Feedback box pops up. Click Close. 
• You will be shown a table with your feedback next to each relevant question.  
• Scroll to the bottom of the table and click on the yellow ‘Please complete your details to submit your feedback’ button. 
• When filling in your details it asks if you are responding on behalf of an organisation. Click no, as you are not responding on behalf of the RSPB but are responding as an individual in response to the consultation. 
• When complete, click the blue ‘Review your feedback’ button 
• Another ‘Review your feedback’ box will appear. Click Close. 
• Scroll down the page that holds your answers and personal details and click the ‘I’m not a robot’ button.  
• Finally, click the blue ‘Submit your feedback’ button.
• A ‘Successful Feedback’ page should appear to confirm your feedback has been received safely.  

Thank you for taking the time to speak up for nature.