"Project Ground Water". - Find a freedom of information request

This FOI Request relates to the Council's 2023 project to investigate boreholes in the Lincolnshire.

In April 2023 Lincolnshire County Council issued a Press Release about "Project Ground Water". This project was one of 25 nationally funded by Defra as part of the £200m Flood and Coastal Innovation programme first announced in 2020.

The Press Release, picked up locally in the Bourne area, stated that Bourne would be included in the initial trials as there where between 37 and 74 wild boreholes that are continuously and uncontrollably discharging thereby causing flooding and loss of ground water from a water-stressed area.

1. The location, by grid references, of each of the wild boreholes included in the Project that are in the Bourne area;

2. Which ones, and how many, are on private property.

3. How the boreholes were selected for inclusion, including,

i). The full criteria used to select the boreholes to be included in the Project, including the criteria used to exclude any boreholes from the Project.

ii). Details of any public consultation process in drawing up the list.

iii) What bodies and agencies (including water companies) were involved in drawing up the list.

iv). Were any boreholes included because of previous complaints made to official bodies, including Lincolnshire County Council.

4.The current flow / discharge rate from each of those boreholes.

5. The acceptable flow / discharge rate from each of those boreholes.

6. The criteria, including, flow / discharge rates that is used to classify a borehole as "wild".

7. The flow / discharge rate from a borehole that the Council, or other relevant body, considers to be an acceptable loss

8. Timescales for the Project and the criteria to be used to assess its success and efficacy.

9. Total sum(s) to be received by Lincolnshire County Council, from both central government and County resources, for the work.

10. An explanation of the Council's powers and obligations, including right of entry (with a court order if appropriate) to private property, to investigate, to inspect and to order work to be carried out on boreholes suspected of being, or are, wild.

I can confirm that the information requested is held by Lincolnshire County Council. I have detailed below the information that is being released to you.

Relevant background information

The Lincolnshire Limestone is a major UK aquifer that occurs in a band that runs from Peterborough in the south to the Humber estuary in the north. The western edge of the Lincolnshire Limestone forms a scarp slope that runs through Lincolnshire and is most noticeable in Lincoln itself. To the east, the Lincolnshire Limestone dips underneath other geological strata meaning it is no longer found at the surface. In the vicinity of Bourne, the top of the Lincolnshire Limestone is approximately 30 m deep underneath various strata including the Oxford Clay which forms an impermeable cap to the Lincolnshire Limestone aquifer. This confining cap means that groundwater in the aquifer in the vicinity of Bourne is held under pressure such that, if a borehole is drilled down into the aquifer, groundwater overflows from the borehole without the need to be pumped. This is an artesian borehole. A well-constructed artesian borehole will be effectively sealed and capped with appropriate pipework (headworks) so that groundwater discharge is only allowed to occur as required for the borehole’s intended water supply. However, over time poorly maintained or abandoned artesian boreholes can deteriorate to the point that groundwater starts to discharge at ground level. This may be caused by gradual corrosion of the headworks or deterioration of the metal borehole casing at depth or due to physical damage to the headworks – for example, from agricultural machinery. Uncontrolled groundwater discharge from artesian boreholes can be quite minor or in some cases quite dramatic. There is no formal definition of a ‘wild borehole’ the term would typically be used to describe an artesian borehole from which it is visually evident that groundwater is discharging in an uncontrolled manner.

The first survey of ‘wild boreholes’ in the Lincolnshire Limestone was carried out in the 1970s which was followed up by a major programme of works in the 1990s to control 30 ‘wild boreholes’ in the fenland area in the vicinity of Bourne. The objective of these works, commissioned by the National Rivers Authority and implemented by Halcrow, was to conserve groundwater resources in the Lincolnshire Limestone aquifer for the purposes of public water supply and the environment (springs and baseflow into rivers). A further survey of ‘wild boreholes’ was undertaken by the Environment Agency in 2013.

1. This Project Groundwater investigation looking at ‘wild boreholes’ in the Lincolnshire Limestone aquifer started with a list of 77 possible ‘wild boreholes’ compiled from locations listed in the Halcrow report (1993 - 20003247.pdf (freshwaterlife.org)) and the Environment Agency Survey (2013).

2. The majority of these boreholes are located on private property. Site surveys to date have focused on rural locations in the vicinity of Billingborough where boreholes are typically located on private farm land, including land owned by the Crown Estate.

3.1. There were no official criteria used to select boreholes for the investigation. As mentioned in Q1 the starting point was the borehole locations identified in the Halcrow and Environment Agency surveys. Subsequently some additional locations have been added from the borehole records held by the British Geological Survey and information gathered during site visits. Only boreholes that are deep enough to penetrate the Lincolnshire Limestone aquifer have been added.

3.2. There has not been an official public consultation process in compiling the borehole list. However, the National Flood Forum (NFF) have led on community engagement, making contact with landowners for the borehole locations to find out more information and enquire about access for site visits.

3.3. The borehole list has been drawn up by AtkinsRéalis with some input from Lincolnshire County Council and Anglian Water. In addition, there are many different project partners that are part of the steering committee for the Project Groundwater investigations in Lincolnshire, including South Kesteven District Council who register private water supplies in the Bourne area.

3.4. 2 of the 77 boreholes on the list were supplied by Anglian Water due to previous concerns made to them by affected residents.

4. Of the 25 borehole locations visited so far during the project (mainly Billingborough area), uncontrolled groundwater discharge was confirmed at 3 locations. It was possible to measure the discharge rate at 2 of these locations – 0.34 l/s and 0.37 l/s.

5. The primary purpose of this investigation is to assess the flooding risk posed by ‘wild boreholes’ which is not necessarily proportional to the discharge rate. For example, a large uncontrolled discharge from an artesian borehole in a farmland location may pose very little flood risk because the groundwater drains to an established network of field drains, whereas a smaller discharge from an artesian borehole in an urban location could pose a significant flood risk.

6. There is no formal definition for a ‘wild borehole’. For this investigation, any borehole from which it is visually evident that groundwater is discharging in an uncontrolled manner would be described as ‘wild’.

7. This investigation has not set out to assess what is an acceptable loss of groundwater from an artesian borehole. The primary purpose of this investigation is to assess the flooding risk posed by ‘wild boreholes’. However, discharge rates measured from any ‘wild boreholes’ during the field surveys undertaken during this study will be available to Project Groundwater stakeholders including Anglian Water and the Environment Agency. It should also be noted that although ‘wild boreholes’ represent a loss of groundwater from the aquifer, these long-standing discharges may have become integral to important local ecological habitats, particularly in rural areas.

8. By undertaking various field surveys this project aims to understand the current groundwater flooding risk posed by ‘wild boreholes’ and to understand how that flood risk may change in the future with climate change and changes to licenced groundwater abstraction. Modelling will be used to assess the impact of possible mitigation measures which could be implemented as part of a subsequent phase of Project Groundwater that is programmed to continue through to 2027. The success of the project will be judged against these key objectives.

9. The investigation into boreholes is part of the wider Project Groundwater Greater Lincolnshire programme, which is part of one of the 25 FCRIP schemes funded by Defra. This is a £7.5 million grant that has been awarded to tackle groundwater issues across all of Greater Lincolnshire with a budget allocation for borehole investigation across the county agreed by the board of £432,500 ie £400k for monitoring / modelling / evaluation and £32,500 NFF community engagement.

10. At present the Councils powers and obligations, including right of entry (with a court order if appropriate) to private property, to investigate, to inspect and to order work to be carried out on boreholes suspected of being, or are wild, is currently not fully understood.

Therefore, as party of this project we are engaging legal experts to explore and define the relevant councils, whether that be county or district, responsibilities and powers moving forward. It should be noted however that if water is flowing across the public highway then LCC as Highways Authority would have a responsibility to intervene under the Highways Act 1980 to manage and maintain highway drainage. If the water is as a result from a person rather than the highway authority, then the highway authority could consider taking legal action against that person for causing a nuisance.