For more than 120 years, water for 80,000 homes and businesses in and around the towns of Egremont, Cockermouth and Whitehaven has come from local sources. But this area is also home to many rare and protected species.  The risk to wildlife, along with the growth of the population means we had to find sources other than Ennerdale Water, Crummock Water, Overwater and Chapelhouse Reservoir.

We worked with environmental stakeholders including the Environment Agency and Natural England and agreed to stop using these water bodies as a water source by the end of March 2023. From then, our West Cumbria abstraction licences are permanently withdrawn and the new water network utilising Thirlmere Reservoir as the water source is fully operational.

Bringing water to the 80,000 homes and businesses via the new 62-mile long pipeline from a more strategic water source, Thirlmere reservoir, means we can better meet the demands now and for future population growth, while also protecting the very precious local environments by not taking water from these smaller sources. 

We also have a legal agreement between ourselves, Natural England, Environment Agency and DEFRA (Department for Environment, Food and Rural Affairs) under the Habitats Directive to cease abstraction from these water bodies.

We have undertaken significant investment over the past 15 years and continue to do so, to enable more water to be moved around our network regions more readily. 

An example of one of these projects is the West East Link Main that connects Liverpool to Manchester, enabling Manchester to be supplied by alternative sources and is therefore less dependent on Thirlmere.

Thirlmere is a large strategic water source and part of our integrated regional water supply system.  When the entire new west Cumbria water network is operational, we will be using more of the water from Thirlmere to supply homes and businesses in Cumbria and use capacity at other sources in the south of our region to make up the difference. 

Our Water Resources Management Plan (WRMP) sets out how much water we think our customers need, how much we have available and how we will meet that supply and demand over the next 25 years. 

Experts assess and model what will affect the demand for water in the future and take into account factors like population growth and the impact of climate change.  Based on those assessments, which have also been subject to scrutiny by a DEFRA appointed planning inspector, Thirlmere is the right solution to meet the needs of the population now, and in the future. 

You can view our updated draft Water Resources Management Plan which defines our strategy to meet demand from 2025 to 2085. 

As part of the legal obligation in operating a reservoir, we are required to conduct regular weekly inspections, as well as a 10 year inspection undertaken by an independent Qualified Civil Engineer (QCE).  In the previous inspection by the QCE at Crummock Water, repairs and upgrade work was identified which needed to be carried out by 2028 to comply with the Reservoir Safey Act 1975.

The work would require replacement of the weir, improved overflow system and replacement of the wave wall.  In the event that Crummock Water was retained, significant construction and disruption would be required.  This would also introduce large expanses of new concrete and assets that would have a significant impact both visually, and to the environment.

The need for additional works is reviewed every 10 years in-line with current legislation, so there is no guarantee that if the weir was kept, the site may still require significant additional investment in 10 years time.

The weir at Crummock Water is not designed or operated as a flood risk management provision as the structure is designed to retain water for drinking water abstraction, above and beyond, the natural storage provision of the lake.  If the infrastructure was abandoned, someone would have to take ownership and responsibility under the Reservoir Safety Act to modify the infrastructure into a flood management system, combined with the liability of proactively managing flood waters. Re-naturalising these reservoirs is the most viable solution due to a reduction in flood risk, enhancements to the environment and cost.

We must demonstrate to the Environment Agency and Cumbria County Council that our assessment of flood risk is in accordance with National Planning Policy and that flood risk to, and from the proposed projects can be managed effectively without increasing risk to others.

We've engaged with specialists to carry out extensive hydraulic modelling studies to assess how the proposed work at all three sites may alter flows. The key findings are detailed below.

Crummock Water

Crummock Water is full nearly all of the time and flood flows are easily transmitted through the system and out into the River Cocker. Therefore, the weir does not currently provide any flood attenuation benefit to help manage flood risk downstream.

Removing the weir will lower the typical water level within Crummock by approximately 1.35 metres, creating greater natural storm attenuation capacity.

The new outlet from Crummock Water would consist of two naturalised river channels, each approximately five metres wide.  The two new outlet channels, combined with a natural 'rougher' surface act as a throttle, holding back water during a storm event and slow the flow of water passing forward from the lake in comparison with the existing forty metre wide smooth outlet weir.

Work at Park Beck would also contribute to reducing flood risk. The lower course of Park Beck is currently a straight concrete channel and provides an efficient way of transferring storm water into the reservoir. Our proposed work would remove this concrete channel and return the natural curves of the watercourse. This would reduce the rate at which the water enters into the reservoir, with multiple channels that would create several points of entry during high flows and remove the pathway for flood water to bypass Crummock Water and flow straight into the River Cocker. 

The combined effect of lowering the water level in Crummock Water, the two re-naturalised outlet channels and the re-naturalisation of Park Beck would all contribute towards reducing the risk of flooding.

The modelling is also assessing the impact for both flow and flood level throughout the River Cocker catchment and into the River Derwent at Cockermouth.

Chapelhouse Reservoir and Overwater

Chapelhouse and Overwater reservoirs, like Crummock Water, are not designed or operated as a flood management provision.

The weir at Overwater was designed to retain a larger volume of water than would have been stored in the natural lake.  The dam at Chapelhouse was designed to create a body of water in the natural valley of the River Ellen (that is diverted around, and perched above the reservoir) to then allow water to be abstracted for drinking water purposes. 

Chapelhouse does not route flood waters through it, this is done naturally along the River Ellen.  The reservoir is nearly full all of the time which provides little flood attenuation provision as it acts to store and retain water 'offline' for water supply and abstraction. 

Removal of Chapelhouse does little to change the natural hydrological regime. Our modelling is also assessing the impact for both flow and flood level throughout the catchment down to Maryport.

Click the links below to take a look at graphics and aerial images which help to demonstrate the existing and proposed top water levels at Crummock Water and Overwater.

Aerial images: Crummock Water and Overwater

Graphics: Crummock Water and Overwater

We understand that these reservoirs are valued spaces and an important landscape for visitors and the surrounding communities.  We're working closely with the Environment Agency, Natural England and our specialist ecology contractor to carry out a wide scope of surveys and assessments.

The projects would deliver several environmental benefits including;

• The restoration of natural salmon habitat
• Removing barriers to fish and eel movement
• Restoring natural flows and sediment transportation
• Habitat enhancement such as tree planting, which form an integral part of our planning applications.

How will the project impact Arctic charr?

The removal of the weir should have a positive impact because a physical barrier has been removed, increasing migration opportunities for the fish community and allowing them to move more freely in, and out of Crummock Water, increasing population numbers.

An assessment of the substrate in shallow spawning activities has been carried out. Effectively, there will be a temporary reduction in the optimum spawning habitat and an increase in sub-optimal habitat for Arctic Charr.  With time, the substrates (stone sizes) will naturally start to return to their previous state and provide an ideal spawning habitat.

The removal of the weir will have other more subtle changes relating to lake hydromorphology, changes in water level and silt deposition may have both positive and negative impacts on the spawning activities of Arctic Charr.  Other changes relating to the wider fish community may also influence Arctic Charr communities such as restoring connectivity for other species like brown trout and salmonids.

We'll ensure that contractors appointed to carry out the work are experienced at working in sensitive locations, following practices during the construction period to protect the local landscape and habitats including sediment control to reduce impact to rivers, streams and lakes with measures in place to reuse materials in the wider scheme.

During the construction phase access to several areas around Crummock Water will be restricted, along with closures of some access routes, as safety is of utmost importance. 

We're working to establish the most appropriate solution to allow safe access to be returned to users as quickly as possible.  We will also look to provide alternative routes, where feasible, to maintain access to the areas which would not be impacted by the proposed work. 

There would be a need to undertake some permanent Public Rights of Way diversions.  We're working closely with the Lake District National Park and National Trust to make sure that following the work pedestrian access is not restricted and impacts are minimised as much as possible. 

It is likely that the use of the National Trust car park at Lanthwaite Wood will be restricted while the work is carried out.  We are looking at the provision of alternative parking during the proposed work.

The use of Crummock Water for swimming and other water based activities (excluding powered crafts) is the responsibility of the land owner, National Trust.  We are not aware of any plans to change the current recreational activities following completion of our proposed work.  However, the lowering of the water level will widen the lake margin, which in turn could potentially change recreational access to the water from the gravel shoreline. 

Following queries at our community drop-in sessions, we have carried out assessments to better understand the shoreline gradients and, by lowering the water level, whether this would significantly impact access to the water for recreational activities.  View these heat maps which show the shoreline lake margin gradients against both the existing and proposed water levels.  

Further information regarding access, activities permitted in which lake and swimming in the Lake District can be found on the Lake District National Park website

We're also carrying out feasibility studies to explore a range of options to help evaluate and develop our long-term plans for Ennerdale Water - using the knowledge and learning from the projects at Crummock Water, Chapelhouse Reservoir and Overwater will be invaluable.

The plans are very much in the early stages and there are lots of things to consider including:

• Impact on the environment
• Protecting and enhancing habitats
• Flood risk

As we work through the feasibility studies and investigations we'll be holding further sessions about our plans for all these water bodies.

We hope you have found this information about our proposed long-term plans helpful, we'll continue working to develop these and our team will be holding further drop-in information sessions in September 2023 between 1pm and 7pm at the following venues.

The Kirkgate Centre, Cockermouth on 26 September, Loweswater Village Hall, Cockermouth on Wednesday 27 September and The Globe Hall, Ireby on Thursday 28 September. 

If you have any queries, please complete our feedback form

You can view the EIA Scoping Opinion for Crummock Water and associated documents on the Lake District National Park website