27th August 2022
In an earlier post we published questions put to SCDC cabinet by Hilary Stroude and Council Leader Bridget Smith’s response. Feeling these answers to be inadequate in many respects, Hilary subsequently sent a list of comments and follow-up questions to Ms Smith. A few words have been edited to suit the formatting of the online version.
To date, no response has been received to these additional questions.
Q1: ‘The mapping information received suggests that the completed system does not interfere with the RTD layer so the greenways should not result in conveyance of groundwater from the site’.
The H R Wallingford Report stated that two phases of dewatering had taken place on Phase 1, in 2015 and 2016. The photo below shows the Kingfisher Pond in the winter of 2015 -2016, less than 6 months before dewatering started out on the Phase 1 site. The damage caused by Northstowe works are clear for everyone to see.
The next two photos were taken in 2017 in January – February, approximately 6 weeks apart. The Kingfisher pond is empty yet there is clearly a considerable quantity of water in the greenway heading towards the Phase 1 lake (note the Pathfinder School in the distance). There should have been no dewatering taking place at this time so where has the water in the greenway come from and why are the RTD deposits not beginning to recharge by this time?
How is it possible to know whether the groundworks have deviated in any way from the original planning application when most of the drainage infrastructure has been buried under houses and roadways? It is for this reason that it was vital that SCDC inspected the site in 2016, when groundwater issues across Longstanton were first reported. What investigations have the officers carried out which allows them to be certain that there has not been significant departure from the plans?
It cannot be an excuse that LPA relied on advice and guidance from statutory bodies such as the Environment Agency. There was a fear of flooding for Longstanton but the unique hydraulic properties of the RTD deposits and its associated groundwater should have been considered. It was not up to LPC or local residents to ensure that all aspects of environmental protection from deep drainage and dewatering was considered, that was the role of the LPA. Failure to carry out due diligence or ask the right questions is also a failure of the LPA, who are experienced in dealing with planning matters. If you are going to build 10,000 houses largely on top of RTD gravel deposits and allow industrial scale dewatering in the driest part of the country – there are clearly going to be problems. You simply cannot dewater within a hydraulically connected area and expect that not to be the case. Maybe the site was simply not a sensible one to have chosen for such a large scale development. The implications of the developer’s proposals should also have been identified by the firm that wrote their drainage and groundwater planning documentation (which I think was WSP).
If there was a failure to carry out due diligence and a failure to identify the full impacts of the drainage and dewatering proposals, then SCDC as the planning authority should have taken action in 2016, prior to the second phase of dewatering. It was clear by then that environmental damage was resulting from Phase 1 works. Dewatering should have been stopped immediately until a proper assessment of the environmental impact was made and understood.
Q2. Why has an independent survey of the swales not been commissioned?
The scale of the environmental damage across Longstanton is so serious that this should be done as a priority. L&Q may provide ‘as built’ plans and although these have been compared with on-site positions it is simply not possible to determine whether buried infrastructure has compromised the integrity of the RTD Deposits. SCDC should not be relying on L&Q to provide information on this issue as the information provided is not impartial or independent and that is not giving Longstanton and its residents the independent representation that we need and expect.
The on-going survey worked organised by LPA is welcome but Longstanton residents would like to know who is carrying out this survey work – is it independent of the developer?
Q3. This is a main issue – I asked what mechanism the planning permission for filling the lakes was. As Leader of SCDC you should know this, it doesn’t need to rely on someone else making comments. We also wish to add an additional question here: “What mechanism is currently in place for filling the lakes”. These questions are simple and the answers should be known by SCDC – they will certainly be known by both L&Q and Homes England. We would like answers to these questions as soon as possible.
Q4. It is not possible to argue that Longstanton was environmentally safeguarded because surface water flooding risks were managed effectively. There is more to environmental safeguarding than that and LPA was notified from December 2015, that ponds were drying up and fish were dying! Why was no mitigation put in place immediately to safeguard Longstanton water features from the reported negative impacts of the Northstowe development? It is rather shocking to have it acknowledged that consideration of groundwater impacts were not fully considered from the start.
I do not agree with the part of the statement which says ‘As knowledge and understanding of the issues around groundwater have increased over the life of the development at Northstowe…..’ The impacts of the dewatering on ponds and wells across Longstanton was raised within months of work starting out on Northstowe Phase 1 in 2015. If the concerns of residents had been responded to immediately and in a timely manner there may have been an opportunity to have prevented the escalation of the environmental damage we have witnessed in the village. There is little point ‘extensive consideration’ being given to this escalating issue when it results in no action being put in place to safeguard Longstanton and our environment.
You have stated in previous answers that the initial plans for Northstowe focused on preventing floodingwell that has certainly been achieved! It is therefore clear that there were failings with regards the original focus and remit of the planning permission and these errors, omission or failings (call them what you will) need to addressed by revising the planned drainage scheme for the parts of Northstowe not yet built. It cannot be acceptable to continue with more of the same just because of flawed plans and decision making, which took place well over a decade ago.
Q6. This response does not answer the question posed. Local residents witnessed the water level in the Phase 2 lake being lowered manually so that the bridges could be installed. Since then there has been very little rainfall and none recently. Longstanton residents want to know how was the Phase 2 lake refilled as we do not believe that it can be from rainfall alone? If it does rely on rainfall alone then it will not be possible to ensure that the lake remains full of water in the summer. If you look at all attenuation ponds you will see that they lose considerable quantities of water through evaporation. If the stored surface water (meant to be kept at a minimum of 2 metres) evaporates during hot weather how is it being recharged if there is no rain? If the Phase 2 lake is in hydraulic connectivity with the RTD deposits so this minimum water level can be maintained – we would like to know.
The fact that a swimming platform is to be installed proves that this lake is not just being filled by groundwater runoff. The Kingfisher pond is now solely reliant on surface water runoff from the Western Park – there is virtually no water left and even if there was water the quality of it would be hazardous to health if anyone tried to swim there. A swimming lake needs to have a supply of clean and fresh water – where is that coming from? You have said that SISK has confirmed that no groundwater is being abstracted and that no water is being pumped into Beck Brook – that may be so but that does not stop the Phase 2 lake being filled naturally be a connection between the lake itself and the RTD deposits.
Q7. Clearly LPA is not taking the environmental destruction of Longstanton seriously. If it was it would not have given planning permission for Phases 3A and 3B until there was a full understanding as to what had gone wrong with the groundwater, and what design changes need to be made to ensure that further Northstowe development does not make the situation worse. Northstowe cannot be built at all costs and in total isolation to the damage it is causing the surrounding area. On the right is a photo of the Hatton House pond taken this week. Like the Kingfisher Pond in 2017 – this pond cannot be empty whilst the Northstowe lakes have water. There is simply a disparity here that cannot be explained by differences in rainfall between Longstanton and the lakes. Surely, it would have been expedient to have ensured that a new Environmental Impact Assessment was required for Phase 3 so that drainage of the site could have been designed to help rectify some of the damage that we are seeing?
Q8. ‘The advice of the EA has not been ignored’. The Environment Agency stated that if the Northstowe development was causing damage then that damage should be mitigated for. They wrote that in 2016, if action had been taken then we would not be dealing with such a large-scale environmental problem now. It is now over 5 years since that letter was written, time enough to have taken proactive steps to rectify the damage caused. There can be no excuse for a failure to take positive action to solve the problem.
Q9. Your response suggests some remediation measures to be enacted in the case of the groundwater being lowered on a longer term basis. It is ridiculous to suggest the drop in Kingfisher pond level is due to rainfall events (Ok it would be very low now due to reduced rainfall, but it emptied ages ago and has not refilled at all, if it were due to rainfall, fluctuations would certainly have been apparent over the last year). Therefore SCDC should be chasing the implementation of those actions, not still deciding whether they should be implemented or not.
The H R Wallingford also indicates the hydraulic connectivity through the RTD deposits, so it is inevitable that any work out on Northstowe Phase 3A upstream of Longstanton is going to have further impacts on this village and possibly Phase 1. H R Wallingford should have been commissioned to have investigated this matter further and any new report, and the ones carried out to date, should have formed part of the planning documentation for the Phase 3 planning application. It is irresponsible to give planning permission for a massive development phase whilst sitting back pondering whether any action should be taken as a result of the reports produced to date.
Q10. You state that ‘the Council does not consider the impact of reduced RTD water levels to be insignificant – and is focused on investigating the causes for it’. Why then was planning permission for Phase 3A given when the planning document (NORTHSTOWE Phase 3A Outline Planning Application ES Volume 1 – Main Report April 2020 Chapter 10: Ground Conditions, Contamination and Hydrogeology) contains table 10.11 and 10.12 which clearly states the developments effect on existing buildings, surface water and hydrology will be “Not significant”. The mitigation section of this document also includes nothing about water levels or availability; it only mentions mitigation of pollution and contamination. LPA should not have granted planning permission if it considered the findings contained within this document to be incorrect or inadequate. Failure to mention water levels or availability in the mitigation section is clearly a failure by LPA, as you have already acknowledged the increasing levels of awareness regarding the groundwater issue. There simply cannot be any justification for accepting this document and a new Environmental Impact Assessment should have been asked for.
Q11. The invitation to yourself, Bill Handley and Liz Watts still stands as it would be useful for everyone involved with the Homes and Communities brief and the Northstowe development to come and view Longstanton’s water features with residents whose properties have been damaged. It is only by a site visit to Larksfield Nursery, Hatton House, the Kingfisher pond, Ladywalk pond etc that the enormity of the environmental destruction is apparent. Local residents have property on the verge of being totally destroyed and they have a right to receive high-level representation. The interests of developers and Northstowe planning cannot override the interests of Longstanton and the other surrounding villages.
Q12. The Environment Agency letter of December 2016, made clear that damage should be mitigated for. Our recent meeting with the Environment Agency reiterated the fact that as the planning authority SCDC has to resolve this matter. It is easy to hide behind ‘advice’ being provided by these statutory authorities but, as illustrated by your initial response, the waterpark and drainage plans for Northstowe have been based on a flawed and blinkered single concept, which was to avoid flooding. There are simply no words that can justify the total failure of LPA to safeguard Longstanton from negative impacts of the Northstowe development.
And finally, consideration of H R Wallingford report and any recommendations as to whether the Kingfisher pond may require alternative engineering is simply not enough. Many of us who have been involved with the Longstanton groundwater issue did not agree with the narrow remit under which H R Wallingford was asked to work. However, H R Wallingford proved hydraulic connectivity across the RTD gravels and as a result Longstanton wishes to see the groundwater features across Longstanton given equal priority to the Kingfisher pond and mitigation measures put in place for all the private wells and ponds across this village. It is simply not acceptable for local residents to suffer damage to property and losses as a result of failures in the Northstowe planning process. Damage across Longstanton village needs to be repaired and residents compensated for any loss.