Statera Energy is proposing to upgrade the existing weir structure, to help unlock the potential of pumped storage hydro in the Highlands while safeguarding the navigability of the Caledonian Canal. 

Improving the function of Ness Weir would allow water levels in Loch Ness to be more effectively managed. Ensuring water resilience for all those who depend on the loch. 

• Supporting clean energy by reducing curtailment of pumped storage hydro during low water levels
  
  Pumped storage hydro (PSH) is a vital part of Scotland’s clean energy infrastructure, acting like a giant battery that stores excess renewable energy and releases it when demand is high.
  
  By improving water management and resilience, Ness Weir II will help ensure that PSH projects can continue to operate without interruption, reducing curtailment (wasted renewable energy) and supporting grid stability with low-carbon power.

• Protecting Loch Ness by improving water resilience for all users and sensitive habitats
  
  Loch Ness is not only iconic but ecologically and economically important. Enhancing water resilience means ensuring a more stable and sustainable water supply for everyone from local communities and tourism operators to wildlife and fragile ecosystems. This upgrade supports biodiversity, helps mitigate the effects of climate change, and ensures that the loch remains a healthy and vibrant resource for generations to come.

• Reduce flood risk to Inverness based on the proposed operation of Ness Weir II
  
  The proposed Ness Weir II would be operated in a way that helps regulate water flow more effectively, especially during periods of heavy rainfall. By controlling water levels upstream, the weir can reduce the risk of flooding in Inverness and surrounding areas. This not only protects homes and infrastructure but also reduces long-term costs associated with flood damage and insurance, while improving public safety.

• Enabling greener construction by allowing freight to move via the Caledonian Canal, easing pressure on local roads.
  
  Using the canal network for transporting construction materials and equipment offers a low-carbon alternative to road freight. This shift reduces traffic congestion, lowers emissions, and minimises wear and tear on local roads. It also supports more sustainable construction practices, aligning with Scotland’s net-zero goals and improving air quality for nearby communities.

Ness Weir II presents a major opportunity to attract investment into the Highlands, not just in infrastructure, but in green jobs, tourism, and innovation. By aligning with Scotland’s energy transition goals, it positions the region as a leader in sustainable development. At the same time, it ensures that environmental stewardship remains central, safeguarding Loch Ness and its surroundings for future generations.

The Loch Ness catchment area is a vast and complex hydrological system, supporting a wide range of users including communities, businesses, and energy infrastructure. Most notably pumped storage hydro. This system relies on consistent water availability to function effectively. 

Over the past 40 years, the Scottish Environmental Protection Agency (SEPA) has carefully monitored how much water flows into the Loch Ness catchment. Their data shows that water levels are changing, with more extreme events predicted based on the Regional Climate Models (RCM) from the Met Office’s UK Climate Projections (UKCP), the Ness catchment is likely to experience wetter winters and drier summers, thus increasing the likelihood of water stress. 

Through discussions with existing operators of leisure craft on the Caledonian Canal, Statera is aware that low water levels in Loch Ness have resulted in damage to vessels passing through the canal system. Increasing the average summer water levels will reduce the likelihood of lower water levels occurring and, in turn, reduce the chance of disruption to tour boats and commercial operators alike.

The Loch Ness catchment area is a vast and complex hydrological system, supporting a wide range of users including communities, businesses, and energy infrastructure. This system relies on consistent water availability to function effectively.

In 2017 Scottish Canals, as custodians of the existing weir, reinforced the structure with steel piling. This work was necessary for the weir to continue to function as it does today.

The modifications to the weir proposed by Statera are to future-proof Ness Weir, to allow for the optimised operation of future and planned pumped storage hydro projects, as well as protect Loch Ness and the Caledonian Canal against the predicted impacts of climate change.

The predictions of twelve Regional Climate Models (RCM’s) are shown below, the white line shows the historic average monthly flow rate (from 1981 to 2022), and the red line shows what we expect in the future if no changes are made. The shaded area between the two lines highlights the difference in water flow showing how much lower summer flows if no action is taken.

Figure 1: Ness Catchment Monthly Flow Variations based on 12 no. Regional Climate Models (RCM) based on 2051-2080 predictions.

Statera is willing to play a major part in delivering the structure if consented. However, we also recognise that there has long been a desire to take a collaborative approach to water levels in the Great Glen, working alongside all stakeholders who have an interest in this. Statera sees the management of this asset as best held by an independent strategic body. We are committed to working with all stakeholders involved to deliver a long-term solution on this matter.

The Ness Weir II proposal warrants its own application and consultation, given the potential impacts and benefits extend to those beyond the Loch Kemp Storage programme.

The project is proposed to assist with the operation of the Loch Kemp storage project. However, Ness Weir II alone will also deliver significant benefits to Loch Ness, safeguarding the Loch’s long-term future.

Once operational, the modified weir can reduce flood risk both upstream in Loch Ness and downstream in the River Ness. It is predicted that the modification of the weir will lead to a modest increase in the average annual water level of Loch Ness, from its current median level of 15.82 (mAOD) to 15.94 (mAOD), an increase of 12cm. This prediction accounts for all hydrological conditions experienced within the catchment, including current and future pumped storage hydro projects.

The new control structure will allow for more dynamic management of water levels in Loch Ness. The control system planned for the project will use a pre-release and flood forecasting system to predict and manage high-water events, such as predicted high rainfall or snowmelt, and will also use operational information from the pumped storage hydro schemes. This means the control gates can be gradually lowered to reduce water levels in Loch Ness and Loch Dochfour, in advance of any planned and or forecasted event.

The impact on the potential increased frequency and duration of higher and lower water levels within Loch Ness, and the subsequent flows in the River Ness, will be carefully managed to minimise the impacts during both operation and flood events.

Statera Energy is working closely with the Scottish Environmental Protection Agency (SEPA) to develop a robust approach, which will follow all relevant regulations, including the Reservoirs (Scotland) Act.

A detailed Flood Risk Assessment (FRA) will be submitted as part of the full planning application for Ness Weir II.

The project is being designed to enhance water level management while protecting local ecology. Environmental impacts are being carefully assessed and mitigated through design, construction planning, and long-term monitoring. 

Fish and Aquatic Ecology

• Loch Ness and the River Ness are vital for atlantic salmon, sea trout, arctic charr, eels, and lamprey.

• The existing fish passage structures are being upgraded or replaced with modern designs to improve upstream and downstream migration.

• A small increase in the median water level by 12cm will help reduce low water events, supporting aquatic life.

• Construction will be carefully managed to avoid sediment disturbance and maintain fish passage. A Construction Environmental Management Plan will be in place.

• Ongoing monitoring and adaptive management will ensure fish habitats and water quality are protected. 

Terrestrial Ecology

• The area around Loch Ness and Loch Dochfour includes ancient woodland, riparian habitats, and agricultural land. Protected species such as otters, bats, pine martens, red squirrels, and amphibians are present.

• Ecological surveys are being conducted to access the project impacts on each species. The result of which will be included within the full planning application.

• The project may cause temporary disturbance during construction and more frequent shoreline inundation during operation. However, most sensitive habitats lie above the normal water level range and are unlikely to be significantly affected.

• Mitigation measures and biodiversity enhancements will be implemented, with ongoing monitoring and consultation with NatureScot. 

Birdlife (Ornithology)

• Surveys recorded 40 bird species, including osprey and several Birds of Conservation Concern.

• Ornithology surveys are being conducted to assess the projects impact on the 40 bird species. The result of which will be included within the full planning application.

• Construction may temporarily disturb nesting and feeding areas near the weir, but long-term impacts are expected to be minimal.

• Birds in low-lying areas around Loch Ness are unlikely to be affected by the modest water level changes. Overwintering marine and wading birds are not expected to be impacted.

We’re still in the early stages of consultation, but we’ve already had encouraging conversations with canoeists and kayakers familiar with the weir during our first events in November 2024. Their feedback is helping shape a design that supports safe and enjoyable access to the water.

We’re working closely with local water sports groups to ensure the scheme maintains and enhances recreational use. Key features include: 

• Continued access during high and low water levels: Canoeists and kayakers will still be able to slide over the service weir, just as they do now.

• A new route via the fish pass: The fish pass will also serve as an additional safe passage from the loch or canal system to the River Ness.

• Safety built into the design: Gradients and flow conditions are being carefully engineered to support both ecological needs and recreational activities.

At this stage, the Ness Weir II proposal is still in development, and the construction approach may evolve as plans are refined. We are committed to keeping the community informed and involved as the project progresses, and we welcome feedback throughout the consultation process. However, based on current expectations, engagement with contractors, and experience from the design consultants, the following steps are likely to be involved:

Cofferdam installation

To allow safe and dry working conditions, a cofferdam (a temporary watertight enclosure) would be installed around both the upstream and downstream sections of the existing weir. Water would be pumped out of this enclosure to expose the riverbed, enabling the installation of a new control structure within the existing weir.

Temporary fish passes

To maintain fish movement during construction, temporary fish passes will be installed. This ensures that aquatic life can continue to navigate the river while works are underway. 

Environmental timing and controls

All in-river works will be carried out during designated periods approved under the project’s Controlled Activities Regulations (CAR) licence, which would be issued by the Scottish Environmental Protection Agency (SEPA). These timings are informed by guidance from the local fisheries board to protect fish populations and river ecology.

Minimising disruption

We are committed to reducing the impact of construction on the local community. Where possible, we will make use of the Caledonian Canal to transport large and heavy materials, helping to alleviate pressure on the local road network and reduce traffic related disruption.

Project duration

Due to the seasonal restrictions and the complexity of the works, the construction phase is expected to take between 2 and 4 years to complete.

Our first round of public exhibitions was held in November 2024, which saw approximately 130 people attend our five events over three days. We are grateful for the interest and range of feedback received during this consultation from different stakeholders. 

We have taken the feedback on board and are now presenting our updated proposals to the local community. We are confident that this reflects both the technical requirements of the proposal and the valuable input of stakeholders during earlier consultations, ensuring a solution that is robust, sustainable, and aligned with community and environmental priorities. 

The timeline below sets outs the next steps for the project. 

Proposal of Application Notice (PAN) submitted
October 2025 

First round of public consultation
November 2025 

Second round of public consultation
December 2025 

Application submission
Q1 2026 

Construction begins
2027 

Weir fully operational
2030