28 July, 2022
Photos taken during winter 2014 – 2015 (one of which can be seen below) show the Kingfisher pond full of water. At this time the level of water in the pond could only be reduced using an overflow pipe set in the bank. This overflow pipe would keep the water at a safe level to avoid flooding of the surrounding land. The exposed bank enabled the Kingfishers to nest and a former resident and wildlife photographer took many photographs of the birds when they nested at the site.
The Kingfisher pond and all the ponds and well across Longstanton are ground fed water features. Water from an underground aquifer passes through ancient River Terrace Deposits, commonly known as gravels. When water levels in the aquifer were high the water level in the ponds and wells would naturally rise. In periods of low rainfall the depth of water in these ponds would naturally fall. However, it is worth noting that many residents have lived in the village over 30 years and we can confirm that pre-Northstowe these water features never dried out, not even in the drought of 1976.
We have to remember that all the water features in the River Terrace Deposits are hydraulically connected. This means that if you pull water out of one part of the gravels it sucks water through the system – a bit like sucking up liquid through a straw. If you suck the water out at a faster rate than it can be replenished then the water level goes down. If you continue to suck more and more water out there gets to the point where water levels in the aquifer are below the bottom of our ponds and wells. Once this happens – the pond or well in question will run dry as there is no longer any water coming up from the ground. Longstanton is set on a slight hill with both our churches standing approximately 15 metres above sea level. Northstowe houses and the lakes are at a much lower elevation than Longstanton which means that if you dewater to reduce the groundwater to a level where you can build Northstowe houses with no flooding or the necessity for pile-driving, of course the water level of the River Terrace Deposits will collapse to below the bottom of Longstanton’s wells and ponds.
Why do we keep talking about the Kingfisher pond?
We talk about the Kingfisher pond for two main reasons as it needs to be viewed as a barometer for what is happening across Longstanton. This pond is easily accessible being within the Northstowe development area – whilst, with the exception of the well at St Michael’s church, the ponds and wells in Longstanton are privately owned and the damage to them is taking place behind fences and hedge and is therefore not so clear to see. However, make no mistake they are getting damaged just as much as the Kingfisher pond and in many cases the damage is worse. The independent report carried out by H R Wallingford confirmed that all the Longstanton water-features are hydraulically connected with the Kingfisher pond. This proven link means that what is happening to the Kingfisher pond is happening across the village.
The other reason why there is so much discussion about the Kingfisher pond is that this is the only pre-Northstowe pond that lies within the Northstowe Phase 1 area, and the planning permission for that Phase specifically retained the Kingfisher pond as a pond and a natural heritage asset for Northstowe community. This means that the planning authority should have leverage over the developer to restore this pond to the condition it was in when the planning permission was granted. This permission did not allow for the Kingfisher pond to become the stinking, neglected and dry wasteland that we see today. Because we know that Longstanton’s ponds and well are hydraulically connected to the Kingfisher pond it goes without saying that if development works have damaged the Kingfisher pond then those same works are responsible for the damage that is being reported
across Longstanton.
So how have we got to this point where the Kingfisher pond and the other ponds and wells across Longstanton were full at the start of 2015, but are empty now whilst the Northstowe lakes contain substantial quantities of water?
Drainage and groundworks began out on Northstowe Phase 1 in 2015, with industrial scale dewatering taking place in both 2015 and 2016, and this has been confirmed in the H R Wallingford report. However, within months of dewatering starting on site one of Longstanton’s ponds near to Phase 1 dried out and all the fish died. I emailed the SCDC planning authority to advise them of this in December 2015. By 2016, the situation was worsening across the village and residents were expressing serious concerns to both the planning authority and the Environment Agency (EA). Residents and others went on a site visit to Phase 1 during this period and witnessed water running through drainage channels on the site.
At Northstowe Forums held over the next couple of years the developer stated that the collapse in groundwater across Longstanton was due to ‘a lack of rainfall’ and it was nothing to do with any work being carried out on site. The Environment Agency came out to visit the site at the request of local residents and made clear that SCDC as the planning authority should take action if the development was causing damage. This was reiterated in a letter from EA to SCDC planners in December 2016. By 2017, the Kingfisher pond was dry (as can be seen by the photograph below) and yet video filmed by drone in the same month shows the Northstowe lakes had plenty of water in them. Link to drones video on YouTube.
Under pressure from residents the developers commissioned what was said to be an independent report. This Interim Report concluded that the Kingfisher pond was empty because of lack of rainfall. Requests made by local residents for groundwater monitoring off site across Longstanton were rejected. The Interim Report’s conclusion has been proved by the H R Wallingford report of 2021 to be wrong – the disparity in water levels between the Kingfisher pond and the Northstowe lakes was not caused by lack of rainfall..
Since 2017, the situation has got progressively worse and Longstanton residents and the Parish Council have become increasingly alarmed as more ponds have dried out, fish have died or have had to be located, trees have died, and some buildings have cracked and gardens have subsided. This concern led to the commissioning of the H R Wallingford Report in 2021, by Longstanton Parish Council with the support of SCDC. This report had a limited remit and as yet its recommendations have yet to be implemented to the satisfaction of local residents.
De-watering of the Northstowe site was officially meant to have stopped after 2016, but the aquifer in the River Terrace Deposits has not recovered and the situation is worsening. It is easy to look at the dry and hot conditions of 2022 and blame Longstanton’s problems on the weather or climate change but this cannot be the case; we have the evidence to show that the village has faced this problem since work started out on Northstowe in 2015. Longstanton had plenty of water in our ponds and wells six months before this work started and now we have none! Where is the water coming from to fill a lake so that people can swim in it? The situation could get worse still. Now we have the prospect of Phase 3A (upstream of Longstanton) dropping the groundwater level by another 2 – 3 metres. The damage that this could do to Longstanton is the reason why this new group has been created.
Hilary Stroude is the secretary of the Longstanton & District Heritage Society.