Question and answers

The West Cumbria Supplies Project has been the largest engineering project we've ever carried out.  As we prepare to bring the new network online to start supplying Thirlmere water from spring 2022, we'll be in touch to provide regular updates. 

  • When you say West Cumbria, where do you actually mean?

    Most, but not all, of the people living in the districts of Allerdale and Copeland fall into our West Cumbria resource zone. This includes places like Whitehaven, Egremont, Ravenglass, Workington, Maryport, Silloth, Cockermouth and Wigton. It does not include Millom, Keswick or any of Carlisle. In total that’s about 150,000 people.

    Where will West Cumbria’s new supply come from?

    We consulted widely on several potential options and also carried out some additional research. The research indicated that most people in Cumbria favoured using Thirlmere Reservoir to provide the source of raw water.  

    Thirlmere reservoir will give the area a reliable, resilient supply capable of meeting the forecast demand for water in West Cumbria for at least the next 25 years.  It has more capacity than smaller local supplies to cope with any upsurge in water demand from tourism or industry.

    Why did you rule out the Kielder option?

    It’s a good option, that could deliver all the water West Cumbria needed, but it would have been expensive to build and run because of the expense of pumping such large amounts of water long distances. Also, it would have taken much longer to construct.

    Why did you rule out the local sources option?

    Although it would have been cheaper and easier to build, we believed there were too many uncertainties to guarantee that local sources would be able to meet West Cumbria’s demand for water in the very long term. For instance, some of the sources may themselves become more environmentally sensitive and the area would still be susceptible to short term droughts. 

    What impact will this have on the landscape and environment?

    Most of our new infrastructure is buried out of sight leaving no lasting visual impact. It will also mean we can return many other man-made features like weirs and intakes back to a more natural state. Not just in Ennerdale, but potentially at places including Crummock Water, Overwater and Dash Beck, which will no longer be used to supply water.

    Where would the new water treatment works be?

    Our new water treatment works has been built off the A595 near Redmain. We considered several possible locations including Bridge End, near Thirlmere; at Bothel Moor, near Aspatria;  at Cockermouth and at Bridekirk.

    How will you keep disruption to a minimum?

    This is a huge project, and we've taken steps to minimise the disruption for all areas where we've been carrying out construction work.

    Why could you not use sea water by building desalination plants?

    Desalination was considered, along with many other options, as part of our Water Resources Management Plan. It didn't form part of our strategy because the costs – including environmental and social costs – are about four times higher than the more traditional alternatives.

    How long has it taken to construct the new water infrastructure?

    This has been an extensive and challenging project with many land and environmental impacts to overcome. Although planning began many years before, we started the construction in 2017 and the area’s new water supply will be up and running in spring 2022.

  • How do you know Thirlmere will have enough water?

    Thirlmere is part of our integrated regional water supply system. When the new supply system comes on line we will be using more of the water from Thirlmere for customers in Cumbria, and use capacity at other sources in the south of our region to make up the difference.

    Our Water Resources Management Plan is an official document, in which we set out how much water we think our customers need and how much we have available over the next 25 years. Our experts have assessed and modelled all our water supplies and taken uncertain factors like climate change and licence changes into account. We are confident that there is more than enough capacity in Thirlmere to supply West Cumbria.

    Our plans were scrutinised by the Defra-appointed planning inspector which give the assurance that this project was the right solution for West Cumbria.

    How is taking water from Thirlmere any better than taking it from Ennerdale?

    Thirlmere is a man-made reservoir and was designed to supply water. It has an abundant supply and is already connected to our huge interconnected network of pipes which serves most of the rest of the North West.

    Will this project mean you change the current management agreement you have for Thirlmere with Keswick Flood Action Group?

    No, we can supply all of West Cumbria’s needs without changing the agreement we currently have with Keswick Flood Action Group. In fact, our modelling suggests that increased abstraction of water from Thirlmere might even provide some slight additional beneficial flood risk alleviation for communities downstream. 

  • Will the project create local jobs?

    During construction, we've employed in the region of 500 people throughout the supply chain, with approximately 200 of those being local. We're continuing to recruit local apprentices too.

    Have you used locally sourced supplies during construction?

    As much of the engineering equipment and local materials such as quarried stone, concrete and cement have been sourced locally during the project. 

  • Where are your water treatment works in West Cumbria and which areas do they serve?

    There are four which currently supply the West Cumbria resource zone - Ennerdale, which supplies around 80,000 people in and around Whitehaven; Cornhow, which supplies around 45,000 people in and around Cockermouth and Workington; Quarry Hill, which supplies around 20,500 people in north-east Allerdale; and Buttermere, which supplies around 50 people in and around Buttermere.

    What effect will the project have for the future of your existing water treatment works?

    Our project involved the construction of a new water treatment works off the A595 near Redmain which will serve the whole of West Cumbria. 

    Once the project is completed, this means that the existing water treatment works will stop abstracting and treating water. They will be shut down while we complete work to decommission them, but no decisions have been made on the long-term plans for those sites.

  • What size will the pipe be?

    The pipework between Thirlmere and the new water treatment works will be twin 900mm diameter pipes laid side by side.  The width of our working area (easement) will be around 40 metres.

    The distribution pipe network which will take the treated water from Williamsgate will be between 400mm and 600mm in diameter with a working easement area of around 20 metres. 

    How long will my land be affected for?

    From taking entry to restoration of the top-soil and re-seeding will typically involve the loss of two growing seasons.  However, where possible we will aim to be quicker by using a specialist contractor to follow behind the main pipe laying contractor. We’ll ensure that your land is put back as it was before.

    At what depth will the pipe be laid?

    Our pipes are laid with 900mm of ground cover.  The large diameter trunk main, which is gravity fed, may require some sections which are deeper (up to 3-4 metres) however these sections should be relatively short.  Generally the distribution mains will be laid with 900mm of cover and some sections may be sliplined which is using our existing mains as a sleeve.

    I have extensive land drainage systems - how will these be reinstated?

    Under the Water Industry Act 1991 we must follow the Code of (best) Practice.  In accordance with this we will try to plan the route to avoid drainage schemes but this will not always be possible. Prior to starting we will, where possible, identify existing drainage schemes through consultation with landowners. Where it is known that we will affect a system of lateral drains, ADAS will prepare a drainage scheme which may involve the installation of a cut-off drain.  The cut-off drain will be installed by a specialist agricultural contractor as part of the preliminary works and will typically be laid outside the working area.  Where individual drains are encountered these will be cross-connected with the work photographed and where possible witnessed by the landowner.  Accurate records and as-laid plans will be maintained.  We will inform the landowner of any drains not previously known to exist. 

    I am anxious about surface water run off leading to soil erosion whilst the works are in progress

    As part of their Land and Drainage Report ADAS will assess the risk of soil erosion, (e.g. from steeply surrounding topography) and recommend mitigation measures. Another useful tool in controlling surface water erosion is not to soil strip too much working area in advance of construction.  Timely restoration by the specialist agricultural contractor will also reduce the duration that land is exposed to the risk of soil erosion.

    Do I need the services of a Land Agent?

    We will pay for you to be represented by a Land Agent whose fees will be paid in accordance with the standard Ryde’s Scale fee accepted by the industry.  Many Land Agents are highly experienced and will act in your best interest to mitigate the projects affects whilst preparing compensation claims and handling correspondence and meetings.  For a pipeline project of this size their services are recommended.

    How much compensation can I expect under the Water Industry Act 1991?

    We are obliged to assess compensation under Schedule 12 on the basis of any depreciation (reduction) in value to the land and any loss or inconvenience arising from the carrying out of the works.  Normally claims can be compartmentalised into Notional Easement, Crop Loss, Reinstatement and Disturbance.  Your Land Agent will be familiar with the Heads of Claim and their parameters under Compensation Law.  Please note a claimant is under a duty to mitigate his loss and should do so wherever possible.

    Will you make a good job of putting my land back as it was before?

    We will employ ADAS to prepare a technical Land Condition and Drainage Report.  Our Land Agent will also complete a Record of Condition for future reference following completion of our work and everything has been put back as it was before.  Our intention is also to engage a specialist agricultural contractor to erect the pipeline fencing and any agreed accommodation works (crossing points etc), including the installation of any drainage works e.g. cut-off drains that have been identified as being necessary.  The specialist agricultural contractor will also be responsible for stripping the top-soil and setting this to one side.  Following this the pipeline contractor will lay his pipe during which time the specialist contractor will be used to cross connect any drains with their position recorded, and if possible witnessed by the landowner. Once pipe laying is complete the specialist agricultural contractor will return to replace the top-soil, working only when conditions are appropriate to handle top-soil.  Re-seeding will then follow although in a few cases some landowners may prefer to re-seed their own land.  The timing of re-seeding is crucial and should not be too late in the season or too early using good quality seed applied at generous seed rates.

    Can I keep the pipeline fencing?

    On completion of the project and following re-seeding it is normal for pipeline fences to remain in place until light grazing pressure can be exercised on the working areas and the fences removed.  The normal arrangement is that in return for taking down the fences the landowner may keep the materials and temporary gates, all of which are normally of a good reusable quality.  In those situations where a landowner is unable to remove the fencing then the agricultural contractor will return to take it down and will remove from site.

    How close can I build to the pipeline?

    It will not be possible to build over the easement width for the pipeline which will typically be an area three metres either side of the pipeline.  On our large water pipe a wider easement may be required and this may necessitate a wider easement and greater protective area, possibly 5 metres each side of the pipeline. 

    Do I receive an annual wayleave?

    No. Payment is a one off capital payment.

    What rights do you have over my land?

    We have a right to operate and maintain our pipe through creation of a statutory easement when Notice is served under the Water Industry Act 1991.  It must however pay appropriate compensation under Schedule 12. If at any time we wish to subsequently alter, renew, or maintain the pipe we will serve a six week Notice.

    Will you make a Record of Condition?

    We will make a full photographic Record of Condition of the working area.  Any buildings in close proximity to the proposed pipeline may be subject to an independent structural survey.  The Record of Condition will help to ensure the land is returned to a condition as near as possible to what existed beforehand. 

    How will the work be supervised?

    We will make sure that anybody working on your land is properly supervised and do not stray outside the agreed working area.  If you have notified us of anything that requires special attention then we will ensure that it is brought to the attention of our contractors who may need to take it into account.

    How will you maintain access to my land?

    It is essential that you can maintain access to your property wherever possible and within reason we will let you have access to fields by provision of crossing points across the working area.  If it is necessary to sever some areas of farmland then we will discuss this with you. Where appropriate we will provide pedestrian crossings, gates and stiles to assist your access to the land.  Where possible we will ensure there is minimum interference with any existing accesses and especially access required for emergency vehicles. 

    How will you access the land for construction?

    Normally we gain access to our pipeline by working along the working area, however if access is required by any other route we will first consult you and include this additional access route on our Section 159 Notice plan. 

    How will you maintain the security of my property and of the working strip?

    Before the project starts we will discuss the type of fencing required to maintain a safe working area across your land.  If the working area affects livestock we will put up suitable stockproof fencing and ensure that this is maintained throughout the duration of the works and whilst your land is being put back as it was before.  If you have particular security concerns regarding your property we will discuss these with you.

    How will you ensure my top-soil is not lost or damaged?

    Following the Code of Practice we will preserve the structure of the soil.  Where top-soil is stripped from the land we will store it separately from other excavated materials such as sub-soil and rock. When the main pipeline work is finished by the pipe laying contractor, the specialist agricultural contractor will prepare the sub-soil prior to replacing the top-soil.  The top-soil we remove will be restored as far as possible to the condition it was prior to the work and replaced to the same depth and with any large stones excavated during the works not left near the surface. 

    Will you affect my trees and hedgerows?

    Wherever possible we will seek to avoid the felling or lopping of any mature trees, however if this is unavoidable we will consult with you first.  If any trees are subject to a Tree Preservation Order then we will consult with the relevant Authority and abide with the regulations. Any works required to replace hedges will also be discussed and any formal approvals required will be requested from the Local Authority. 

    How will you manage any fishing and sporting rights?

    Neither our staff nor agents will be allowed to carry firearms on the working area or bring animals onto the site (with the possible exception of guard dogs).  If there are any fishing or sporting rights adjacent to the working area we will use reasonable endeavours to see that our work minimises any interference with the enjoyment of them, and where interference is unavoidable we will discuss our works and their timing.

    How will you manage watercourses?

    Where our pipe crosses beneath a watercourse it will be laid in accordance with the requirements of the Environment Agency or the Local Authority.  In the absence of any such requirements the pipe will be at least 300mm below the original clear bottom of the watercourse.  In accordance with Environmental Law we will take precautions to ensure the watercourse is not adversely affected during the construction works e.g. by siltation.

    Do you make special provision for areas affected by disease?

     If you advise us that an area in which we have to work has previously been infected by a disease notifiable under the Animal Health Act 1981 (e.g. foot and mouth) we will follow the requirements of Defra.  Additionally if Defra has imposed requirements to avoid spreading soil born pests and diseases we will comply with them. 

    Can I make private agreements with the contractor?

    If you make any agreements directly with our contractors you should note that we will not be responsible for any consequences, nor intervene in any such agreements.

    Will I have surface structures on my land?

    The operation of a pipeline nearly always requires creation of Air Valves and Washouts at high and low points along the pipeline route respectively.  The construction of these chambers should be identified on the plan accompanying the Notice and where possible we will try to locate them at field boundaries where they do not interfere with farming operations. The finished level of the chambers and their location can be varied (typically flush with ground level) and should be discussed and agreed with our Land Agent/Contractor’s Technical Officer before work starts.

  • Why have you used ground water sources if you're linking into Thirlmere?

    We had to reduce the amount of water we take from Ennerdale until the new pipeline and infrastructure to use Thirlmere as the water source for homes and businesses was completed.  The ability to use additional ground water sources, and the other projects we’ve carried out helped us to reduce the amount of water we abstracted from Ennerdale.

    South Egremont ground water extraction

    There are five ground water extraction points which are linked to Ennerdale Water Treatment Works via a new 13km pipeline. Work also included new pumps and treatment units at Ennerdale treatment works.

  • What work has been carried out at Ennerdale?

    We've carried out work to improve the fish pass on the weir at Ennerdale, so that salmon can migrate from the river to the lake and back again more easily.

    There are some temporary pumps in place which help to keep the River Ehen topped up.  These will be removed once work has been completed on the permanent underground pumps.

    What difference will that make?

    Salmon are an important host species for the River Ehen’s baby freshwater mussels.

    What will happen to the fish pass and weir when you no longer abstract from Ennerdale Water?

    This is something we’re currently looking at and reviewing, but it will be essential for at least five years and possibly more.

  • Why don't you tackle leaks?

    We are continually tackling leakage. In West Cumbria leakage has fallen steadily over the last three years and it continues to fall. Because water stocks here are more sensitive, it’s an area where we are investing more in leak detection and repair than in other parts of our region.

    Across the North West as a whole we have halved leakage over the last 20 years and have met the leakage targets set by our regulator Ofwat for the last seven years in a row. 

    You can help us, if you spot a leak let us know by calling our 24-hour leakline number 0800 33 00 33 or visiting Whenever you report a leak to us, this is what's going on behind the scenes to fix it.  

    If you stopped leakage, West Cumbria wouldn't have a water problem at all would it?

    Unfortunately it’s not as simple as it sounds.  You can never stop all leaks and we estimate that about a third of the water is lost from leaks on customers’ own pipes and not pipes belonging to us. Still we are working on it and the situation is improving all the time.

    What exactly are you doing about it?

    Initiatives like smart water pressure management, which are saving about 600,000 litres a day, have made a big impact. We have also more than doubled the number of leak detection and repair teams and are working with an industry experts on more than 30 new initiatives to find out exactly where the water is going and devise new strategies to cut the amount being lost.

  • Will the alterations to Ennerdale increase downstream flooding?

    Detailed hydraulic modelling has shown that neither returning more water to the River Ehen now, nor restoring Ennerdale to its natural state, will have any negative flood impact on communities downstream.

    Was Thirlmere responsible for the flooding which occured in 2009 and 2015?

     No. The flooding was caused by exceptional rainfall and not the operation of Thirlmere.

    Didn't you open the floodgates at Thirlmere to protect the dam?

    No. Thirlmere is managed in consultation with a number of local stakeholders including Keswick Flood Action Group. 

    Why don’t you operate Thirlmere to protect Keswick from flooding?

     We have an agreement with Keswick Flood Action Group to use the reservoir as much as we can to provide some flood attenuation for communities downstream during heavy rains. That means trying to keep some space in the reservoir when we can to absorb the rain. The amount of space we can make available depends on the time of year and how much it rains. It is a delicate balance because the reservoir is vital in the supply of 700,000 people’s water.

    Will this project mean you change the current management agreement you have for Thirlmere with Keswick Flood Action Group?

     No, we can supply all of West Cumbria’s needs without changing the agreement we currently have with Keswick Flood Action Group. In fact, our modelling suggests that taking more water out of Thirlmere might even provide some slight additional beneficial flood risk alleviation for communities downstream.

  • We have agreements in place to fluoridate the water to customers currently supplied from our existing water treatment works at Cornhow and Ennerdale, and we will continue to fluoridate water supplies to these customers as directed by local and national health authorities.  

  • Ennerdale

    • Ennerdale Water is the name of the lake. It is not a reservoir. It is a natural lake whose level has been raised using a weir at the western end. It is owned by United Utilities
    • Water has been taken from Ennerdale on a large scale since 1849
    • It supplies about 80,000 people in Whitehaven and the surrounding areas
    • Legal restrictions and conditions (consents) govern how much water we can take from the lake and how much we must put back to keep the River Ehen flowing. These are set by the Environment Agency to protect the environment
    • Our consent to abstract water from Ennerdale will be revoked completely in 2022.
    • Ennerdale Water was designated an (Site of Special Scientific Interest) SSSI  in 1964 and the valley is considered to be England’s last wilderness
    • The River Ehen flows out of Ennerdale Water. It was designated an SSSI in 1997 and a Special Area of Conservation in 2005
    • Ennerdale is the most westerly of the lakes and the most remote
    • Ben Gill is a headwater stream draining the high fells southwest of Ennerdale Water and flows into the River Ehen just below the Ennerdale Weir
    • Ennerdale is a deep glacial lake, 2.5 miles long 3/4 mile wide and 148 feet deep
    • The water is exceptionally clear, and contains a variety of fish
    • It’s the only lake in The Lake District that does not have a road running alongside it
    • The closing sequences of the movie 28 Days Later (2002), directed by Danny Boyle, were filmed around the Ennerdale area, and include a sweeping panoramic view of the lake

    West Cumbria water resource zone

    • The West Cumbria resource zone is the name given to the network of pipes which supply about 150,000 people in Copeland and Allerdale with their water
    • The zone covers all of Copeland and Allerdale council areas except Keswick, Borrowdale, Millom and Silecroft
    • Unlike the rest of the North West, it is not currently connected to the huge network of pipes (called the Integrated Resource Zone) which are supplied by our largest reservoirs
    • Being linked to the Integrated Resource Zone , because water can be moved around from where it’s abundant to where it’s most needed
    • As well as Ennerdale, the current main sources of water in West Cumbria are Crummock WaterOverwater and Chapel House reservoir. There are also a few boreholes and streams where we take water. 
    • West Cumbria is home to some very special landscapes and habitats which support species like freshwater mussels, char, Atlantic salmon and lamprey
  • Abstraction

    Water abstraction is the process of taking water from any source, either temporarily or permanently. Environmental controls may be placed on abstraction to limit the amount of water that can be removed. We will need to stop using Ennerdale as a source of water by 2022, as the Environment Agency has confirmed that it will withdraw the abstraction licence for Ennerdale.

    Slip lining

    A new pipe with an outside dimension smaller than the inside dimension of the host pipe is either pulled or pushed into the host pipe. We are slip lining parts some parts of the new network pipeline.


    We need to ensure that we have sufficient water available to support Cumbria's growing tourist industry and water demand, now and in the future.


    Thirlmere, a man-made lake, was constructed in the 19th Century to provide the burgeoning industrial city of Manchester. Thirlmere is filled up entirely by rainwater, the streams bringing it down into the lake.

    Thirlmere Aqueduct

    Completed in 1894, the Thirlmere aqueduct is a feat of Cumbrian Victorian engineering, originally built to deliver water to industrial revolution Manchester. Thirlemre provides about 11 per cent of the North West's water, supplying about 800,000 people.


    A borehole is a narrow shaft bored in the ground, either vertically or horizontally. A borehole may be constructed for many different purposes, including the extraction of water or other liquids.


    A legal right to use property owned by another party for a special purpose.


    The meeting of two or more bodies of water. It refers either to the point where a tributary joins a larger river, called the main stem, or where two streams meet to become the source of a river.

    Wastewater Treatment Works (WwTW)

    Sewage, from household wastewater and surface runoff is collected and treated so that it's suitable to be returned into rivers and seas or reused for fertiliser.


    We will need to stop using Ennerdale as a source of water by 2022, as the Environment Agency has confirmed that it will withdraw the abstraction licence for Ennerdale.

    Castle Rigg Stone Circles

    Among the earliest British sites, the stones were raised in about 3000 BC during the Neolithic period. Our pipeline was designed to ensure we did not impact on such a precious part of our countries history