Swellands Reservoir Discontinuance FAQs

Under the Reservoirs Act 1975 and related legislation, discontinuance means a qualified civil engineer certifies that a reservoir has been modified so it can no longer hold water above the designated legal limit. 

Canal & River Trust (the Trust) proposes to permanently draw down (drain) and discontinue Swellands Reservoir, located in a remote area high on the Pennine Moors above Marsden and Diggle in the Peak District National Park.

The reservoir was drawn down and water levels remain low as a precautionary public safety measure. Following a scheduled 10-year inspection in 2021, a number of safety works were identified as legally required to retain the reservoir, including the construction of a permanent access track to facilitate works to the dam and ensure access for ongoing inspections, maintenance and emergency works. 

Part of the access track was completed in 2023, but it has not proved practicable to complete the final section to the dam due to challenging ground conditions and environmental constraints. A further statutory inspection in 2023 instructed the Trust to keep the reservoir permanently lowered until the reservoir safety works have been completed. The Trust continues to maintain the reservoir in its lowered state. 

Without the full permanent access track, the reservoir cannot be operated legally or safely. After careful consideration of all factors, the Trust has determined it must pursue discontinuance. The reservoir is therefore being kept in its lowered state, with the intention that this will be made permanent through discontinuance.

Canal & River Trust has carefully considered all feasible options, including alternative designs and routes for completing the access track, as well as discontinuance. This has included engaging with Yorkshire Water, as the statutory water undertaker, to understand the implications for water supply. 

After careful consideration of all factors, including assessment of environmental impacts, the feasibility of required access works, and the reservoir’s role in water supply, the Trust has determined it must discontinue Swellands Reservoir in order to ensure public safety, avoid further environmental harm and improve biodiversity through habitat restoration and enhancement. 

As a result, the Trust is preparing a planning application seeking approval for the discontinuance works.

The Trust has considered a range of options to meet its legal safety duties at Swellands Reservoir. In practice, these came down to two possible ways forward: 

1. Completing the permanent access track to Swellands Reservoir to allow for ongoing inspections, maintenance and emergency works, or 
2. Discontinuing Swellands Reservoir in order to meet the Trust’s legal safety duties while avoiding further harm to the protected environment. 

The Trust has considered alternative options for the design and alignment of the remaining permanent access track, but these were found to have an even more harmful impact than the approved final section of track. Without the full permanent access track, the reservoir cannot be operated legally or safely. After careful consideration of environmental impacts, the feasibility of the required access works, and the reservoir’s role in water supply, the Trust has determined it must pursue discontinuance.

Canal & River Trust will be submitting a planning application to the Peak District National Park Authority in early 2026. Subject to planning permission being granted, the Trust expects to commence the work in mid-to-late 2026. 

It is anticipated that the works will be split into two phases. It would begin with preparatory works to enable the discontinuance works to be undertaken safely, followed by works to the dam to permanently reduce the reservoir’s capacity. The former reservoir area would then be restored through a habitat restoration and enhancement programme, allowing the majority of the site to return to upland moorland habitat in keeping with its surroundings.

Subject to planning permission, works to discontinue the reservoir are expected to begin in mid-late 2026 and must be completed by September 2028. This timetable aligns with the statutory date by which maintenance works and plans for more regular inspections and maintenance must be in place under the updated Reservoirs Act 1975.

Based on the current programme, which is subject to change, it is anticipated that the works will take approximately two years to complete.  

The programme is dependent on several factors, including weather conditions, the need to avoid sensitive bird breeding seasons, and the requirement to carry out key works in a continuous and safe sequence. Subject to planning approval, works are expected to begin in late 2026, following determination of the planning application by the Peak District National Park Authority, and to be completed by 2028.

The works will involve cutting a partial V-shaped channel through the embankment to make the current precautionary drawdown of the reservoir permanent. The channel at the base of the V-notch will be formed using reclaimed stone from the site, helping it integrate with the surrounding landscape. The design allows for several smaller pools and a single larger pool to be provided in the reservoir bed as habitat for moorland birds. It also allows small pools of water to form along channels in the reservoir bed, supporting wildlife, while preventing water levels rising in the former reservoir basin over time and allowing the majority of the area to return to upland moorland habitat. We will use the existing permanent access track and construct a new temporary access track in the bed of the reservoir from the western edge of Swellands Reservoir to the embankment to complete the works.

Yes. While the reservoir itself will be safely discontinued and the area restored to a more natural moorland landscape, some man-made features will remain.  

The historic embankment will be largely retained, with a partial V-shaped channel cut through it to make the lowered water level permanent, and the unusual Bull Pit structure will also be retained. The completed section of permanent access track needed to maintain Black Moss Reservoir will remain, and a short section of bog mat track will be kept as a turning point for operational vehicles. Existing spillways will no longer be used and are proposed to be infilled and left in place. Temporary or redundant works will be removed, and disturbed areas restored to integrate with the surrounding landscape.

The Trust has engaged with Yorkshire Water, as the statutory water undertaker, to understand the implications for water supply in considering the case for discontinuance. 

Yorkshire Water has confirmed that Swellands Reservoir storage is not included in its Water Resources Management Plan 2024, and that discontinuing the reservoir will not materially impact long-term public drinking water supply or the water supply to the Huddersfield Narrow Canal.

There will be no impact on the water supply to the Huddersfield Narrow Canal. 

Swellands Reservoir has not supplied the canal directly since the 1940s. Today, the canal is supplied both through a long-standing water-sharing agreement with Yorkshire Water and directly by other Canal & River Trust reservoirs, including Diggle, Slaithwaite and Sparth. Swellands reservoir storage now makes only a small contribution within this wider system. 

Yorkshire Water has confirmed that Swellands Reservoir storage is not included in its long-term water resource plan and that discontinuance will not materially affect canal or public water supply.

No. Swellands is a specific case driven by its individual safety, environmental and access constraints. The Trust continues to maintain and invest in its network of operational reservoirs supporting the Huddersfield Narrow Canal, and there are no plans to discontinue any others.

No. While Swellands Reservoir would be discontinued, the neighbouring Black Moss Reservoir, which the Trust also owns and operates, will be maintained and continue to operate as a reservoir using the section of permanent access track that has already been successfully completed. This will provide an ongoing source of open water in the local landscape.

The Trust is in the middle of a multi-million investment programme to increase the resilience and effective operation of the reservoirs and canals it is responsible for in the region. The Trust is investing a large amount of money in repairs to reservoirs such as Slaithwaite, Diggle, March Haigh, Brun Clough, Redbrook and Black Moss which has helped to secure the water supply to the wider canal network through direct water supply and a water sharing arrangement with Yorkshire Water for the feed of water into canals.

Discontinuing Swellands Reservoir will have a positive net impact on biodiversity and will deliver habitat restoration and enhancement that benefits the ecology and protected status of the local area. The majority of the former reservoir area will be allowed to return to upland moorland habitat, supported by a restoration programme focused on bringing back blanket bog and other appropriate moorland habitats, including wet boggy areas, grassy moorland and heathland. The scheme has been designed to align with the designated features of the South Pennine Moors SAC and the Dark Peak SSSI, while also providing more habitat for moorland birds, including species such as golden plover.

Some limited vegetation disturbance will be needed to safely carry out the discontinuance works. This will be localised and carefully managed as part of the overall works. Areas disturbed during construction, including those associated with the temporary access track, will be restored once the works are complete. More widely, discontinuing the reservoir will allow the majority of the area to return to upland moorland habitat through a habitat restoration and enhancement programme focused on bringing back blanket bog and other typical moorland habitats. Overall, discontinuance will have a positive net impact on biodiversity.

The site will recover through a combination of habitat restoration and natural regeneration, helping it return to upland moorland habitat in keeping with its surroundings. The restoration programme will focus on bringing back blanket bog and other typical moorland habitats, while supporting wildlife including moorland birds such as golden plover. Over time, the restored landscape will integrate with the surrounding moorland and deliver wider environmental benefits.

The reservoir has been drawn down since 2023 as a precautionary public safety measure and remains in its lowered state. Discontinuing the reservoir will make this permanent through works including cutting a partial V-shaped channel through the embankment, which will prevent water levels rising above the statutory threshold over time.  

The proposed works have been carefully designed and will be managed to ensure safety, with hydrology and flood-risk assessments informing the scheme and measures included to help manage downstream flows. Overall, discontinuance removes the risk associated with the reservoir continuing to hold a large volume of water.

There will be some temporary, localised disruption during construction, but public rights of way will largely remain available. In particular, the Pennine Way National Trail, where it crosses the construction access route, may experience short periods of disruption during daily construction activities. This will be managed by contractor staff who will be present to ensure public safety while works take place.

No wider closures of the Peak District National Park are proposed. Public access to the surrounding open moorland will continue during and after the proposed works.  

Temporary access restrictions will apply only to the footprint of the construction areas to ensure public safety and will be removed once the works are complete. Brun Clough Car Park will remain fully open to the public throughout the construction phase, although it may periodically experience additional traffic during normal working hours.  

There will also be some localised disruption to the Pennine Way where the access track intercepts it during construction, but this will be managed by contractor personnel standing by to ensure public safety.

Existing public rights of way, including the Pennine Way, will remain available, and public access to the surrounding open moorland will continue after the works are complete.  

Temporary access restrictions will apply only within construction areas during the works and will be removed afterwards. The temporary access track within the reservoir bed will also be removed and the land restored, helping to protect sensitive habitats and support ecological restoration.  

Black Moss Reservoir will be retained, meaning a body of open water will remain in the local landscape.

The Trust is undertaking a programme of community engagement to explain the proposals and address any questions.  

Information about the plans are for everyone to view at www.swellands-reservoir.co.uk. Questions and feedback can be directed to the project team via email, freephone or freepost. 

In addition, the Peak District National Park Authority will be undertaking a statutory consultation on our planning application, where members of the public can comment on the plans.

You can reach the team by email [email protected], freephone 0800 652 3504 or write to ‘Freepost SWELLANDS CRT’ (no stamp needed). These channels are monitored daily 9am to 5pm, Monday to Friday (excluding bank holidays), and the freephone has an answering facility for enquiries received outside of this time.

We will ensure that local communities living close to the Swellands Reservoir are kept up to date as the plans progress. We will continue to provide more information via our website www.swellands-reservoir.co.uk.