YEAR SIX OVERVIEW
We have made significant progress towards net zero, continuing with a range of activities such as peatland restoration, woodland creation and renewable energy generation, which removed 10,397 tCO2e as part of our internal Net Zero Routemap (2025/26) carbon benefit assessment in Year 6. These activities delivered cost savings, supported source water quality improvements, increased biodiversity/natural capital across 733 ha (or over 1,000 football pitches) and improved our resilience to a changing climate and energy security risks.
Our reported annual operational greenhouse gas emissions – our total carbon footprint over the year – reduced by 16,000 tCO2e to 207,243 tCO2e, compared with 223,214 tCO2e last year. The emissions for 2025/26 have been updated from the earlier reported numbers after a review of population data. This underlying reduction was driven by a lower carbon intensity in grid electricity, alongside continued energy efficiency improvements, with around 4.5GWh of energy savings delivered during the year and renewable energy generation (3.88GWh). Further reductions were achieved through increased use of lower-carbon Hydrotreated Vegetable Oil (HVO) as an alternative to diesel.
We expanded the boundary of our reported operational emissions to include emissions linked to the chemicals used in our water and wastewater treatment processes. These are part of “Scope 3” emissions – indirect emissions generated through our supply chain, including the production and transport of materials we purchase and use to deliver services. This change reflects updated Scottish Government statutory guidance for public bodies, which now requires organisations to report a broader range of indirect emissions alongside those generated directly from their own operations.
By including emissions associated with chemicals used in our water and wastewater treatment processes this added an estimated 18,945 tCO2e to our operational footprint. As a result, the total reported operational footprint for 2025/26 was 226,188 tCO2e. With 2025/26 now established as the baseline year for these additional emissions, we will continue to work to identify opportunities to reduce and optimise chemical use, including the transition to lower-carbon alternatives.
Our carbon reduction activities are vital as a changing climate is threatening our ability to deliver essential water and wastewater services. We must, therefore, adapt our approaches and do everything possible to minimise the carbon emissions associated with our activities and maximise the positive contribution we can make.
We continued to make progress across all areas of our routemap and delivered actions which eliminated, reduced or captured emissions.
Highlights include:
We continue to review our progress and learn from our experiences.
We need to extend our knowledge on process emissions mitigation. After electricity they are our next biggest source of emissions, covering the methane and nitrous oxide associated with our wastewater service. During 2025/26, the UK Greenhouse Gas inventory adopted new emission factors for wastewater treatment process emissions. These are significantly higher than used previously, and the UK water sector is presently working to adopt these factors. We expect this could see an increase in the carbon emissions associated with this activity. We will begin reporting these updated factors from 2026/27. This is expected to have a material impact on the pathway to achieve net zero. This does not mean that the goal is not achievable. It means that we will need to undertake further work into the pathways, technologies and opportunities to mitigate emissions in future investment periods.
With the expansion of our operational emission reporting to include chemicals, we also need to improve our capabilities and identify further opportunities to reduce and optimise chemical use, including testing and transitioning to lower-carbon alternatives.
To reinforce the management, continuous improvement and learning required to embed net zero across all we do, we are continuing to maintain our certification with the PAS2080 (Publicly Available Specification) for carbon management.
We continue to keep our supply chain for HVO under review. HVO is now being used to support carbon emission reductions in the parts of our fleet that are currently unsuitable for Electric Vehicles (EVs) due to load or distance factors and we have now installed three fuelling stations at Daldowie (Glasgow), Henderson Drive (Inverness) and Juniper House (Edinburgh). The HVO we use is certified as not containing virgin palm oil. Following our ongoing scrutiny of our supply chain, we have no evidence to suggest that virgin palm oil has been used.
To address modern slavery concerns in solar panel materials, we have now established an ethical supply chain for solar panels. This is now working well on our large solar renewable schemes but is still taking time to implement for our smaller scale applications on construction sites.
Whilst it was a good year for peatland restoration, several projects still could not be completed due to challenges around gaining support from landowners/tenants in our water catchments.
We can only achieve our Beyond Net Zero ambition by working in partnership and we are continuing to strengthen and expand our activities in this area.
Our 10-year land management plan for Loch Katrine with Forestry and Land Scotland (FLS) was approved by Scottish Forestry (SF) in 2024. This supports the capture of up to 1 million tCO2e over the next 60 years by creating and regenerating 4,380 ha of woodland and restoring up to 400 ha of peatland. FLS continued work this year with 74 ha of woodland planted and over 32 ha of land assessed as reaching sufficient maturity and density through natural regeneration to be re-classified as native woodland this year. We also restored 94 ha of peatland.
One of the UK’s Largest Woodland Project Takes Shape at Loch Katrine
The Loch Katrine catchment also makes an active contribution to the Great Trossachs Forest – an initiative driven by FLS, Woodland Trust Scotland, Loch Lomond and the Trossachs National Park Authority and the Royal Society for the Protection of Birds (RSPB). This will see a rich and diverse mosaic of habitats full of wildlife stretching 16,500 ha from Callander in the east to the shores of Loch Lomond in the west.
Our partnership with the Royal Botanic Garden Edinburgh on their ‘plants with purpose’ programme is progressing well. They are examining and optimising planting schemes to support carbon reduction in blue-green infrastructure projects such as rain gardens and storm water planters and pilot planters have now been installed at the East Gate of the Edinburgh gardens.
Royal Botanic Garden Edinburgh: Plants with Purpose Partnership
One of the most exciting partnership opportunities is the “Pioneer Catchment” initiative, which seeks to set out exemplar approaches to managing water catchments in Scotland. Driven by the Public Services Reform (Scotland) Act 2010, it seeks to address the need for greater collaboration and targeting of investment and action across public bodies to secure cost-effective delivery of resilient and sustainable catchments.
Chaired by the Cairngorms National Park Authority and with a programme board comprising Scottish Water, SEPA, NatureScot, FLS, Scottish Forestry and Scottish Government, pilot work is underway in the River Dee and the Angus Glens / South Esk catchments. The work will engage landowners, farmers and operators across the catchments to implement improved water and land management, and nature-based approaches to deliver resilience whilst also improving biodiversity and capturing more carbon in nature.
And our Low Carbon Concrete Collective (LCCC) with Network Rail, SSE, Scottish Power and Transport Scotland is continuing to make progress. The Collective was established in 2022 to accelerate the development and adoption of the next generation of low carbon concrete in Scotland and is progressing the design and pilot of a product called Recycl8.
Recycl8 – Innovation in Construction
If you would be interested in partnering with us for example to:
please contact our Net Zero lead Elise Cartmell.
To encourage knowledge sharing, our Net Zero Heroes network continues to go from strength to strength. We have around 90 people meeting together regularly from Scottish Water and our supply chain partners to share best practice. It includes people who have enabled and implemented carbon savings and carbon capture opportunities and others who have improved net zero reporting or delivered an exemplary project to help us with our sustainability ambitions. We have also initiated work with some of our key equipment suppliers to better understand how their products will decarbonise over time. This has allowed us to update our pathway to net zero investment emissions.
We are continuing to link in with community groups with woodland planting for our “Wee Woodlands”. In the Scottish Borders, Scottish Water partnered with the Woodland Trust to deliver a community and volunteer planting day at Knowes Dean Reservoir. Whilst at Cocksburn Reservoir in the Forth Climate Forest area over 50 volunteers came together to plant 1,300 native broadleaf saplings.
Volunteers Plant Hundreds of Trees at Borders Reservoir
Scottish Water and Volunteers plant hundreds of saplings at Cocksburn Reservoir
We continued to make progress across all areas of our routemap and delivered actions which eliminated, reduced or captured emissions.
Highlights include:
We continue to review our progress and learn from our experiences.
We need to extend our knowledge on process emissions mitigation. After electricity they are our next biggest source of emissions, covering the methane and nitrous oxide associated with our wastewater service. During 2025/26, the UK Greenhouse Gas inventory adopted new emission factors for wastewater treatment process emissions. These are significantly higher than used previously, and the UK water sector is presently working to adopt these factors. We expect this could see an increase in the carbon emissions associated with this activity. We will begin reporting these updated factors from 2026/27. This is expected to have a material impact on the pathway to achieve net zero. This does not mean that the goal is not achievable. It means that we will need to undertake further work into the pathways, technologies and opportunities to mitigate emissions in future investment periods.
With the expansion of our operational emission reporting to include chemicals, we also need to improve our capabilities and identify further opportunities to reduce and optimise chemical use, including testing and transitioning to lower-carbon alternatives.
To reinforce the management, continuous improvement and learning required to embed net zero across all we do, we are continuing to maintain our certification with the PAS2080 (Publicly Available Specification) for carbon management.
We continue to keep our supply chain for HVO under review. HVO is now being used to support carbon emission reductions in the parts of our fleet that are currently unsuitable for Electric Vehicles (EVs) due to load or distance factors and we have now installed three fuelling stations at Daldowie (Glasgow), Henderson Drive (Inverness) and Juniper House (Edinburgh). The HVO we use is certified as not containing virgin palm oil. Following our ongoing scrutiny of our supply chain, we have no evidence to suggest that virgin palm oil has been used.
To address modern slavery concerns in solar panel materials, we have now established an ethical supply chain for solar panels. This is now working well on our large solar renewable schemes but is still taking time to implement for our smaller scale applications on construction sites.
Whilst it was a good year for peatland restoration, several projects still could not be completed due to challenges around gaining support from landowners/tenants in our water catchments.
We can only achieve our Beyond Net Zero ambition by working in partnership and we are continuing to strengthen and expand our activities in this area.
Our 10-year land management plan for Loch Katrine with Forestry and Land Scotland (FLS) was approved by Scottish Forestry (SF) in 2024. This supports the capture of up to 1 million tCO2e over the next 60 years by creating and regenerating 4,380 ha of woodland and restoring up to 400 ha of peatland. FLS continued work this year with 74 ha of woodland planted and over 32 ha of land assessed as reaching sufficient maturity and density through natural regeneration to be re-classified as native woodland this year. We also restored 94 ha of peatland.
One of the UK’s Largest Woodland Project Takes Shape at Loch Katrine
The Loch Katrine catchment also makes an active contribution to the Great Trossachs Forest – an initiative driven by FLS, Woodland Trust Scotland, Loch Lomond and the Trossachs National Park Authority and the Royal Society for the Protection of Birds (RSPB). This will see a rich and diverse mosaic of habitats full of wildlife stretching 16,500 ha from Callander in the east to the shores of Loch Lomond in the west.
Our partnership with the Royal Botanic Garden Edinburgh on their ‘plants with purpose’ programme is progressing well. They are examining and optimising planting schemes to support carbon reduction in blue-green infrastructure projects such as rain gardens and storm water planters and pilot planters have now been installed at the East Gate of the Edinburgh gardens.
Royal Botanic Garden Edinburgh: Plants with Purpose Partnership
One of the most exciting partnership opportunities is the “Pioneer Catchment” initiative, which seeks to set out exemplar approaches to managing water catchments in Scotland. Driven by the Public Services Reform (Scotland) Act 2010, it seeks to address the need for greater collaboration and targeting of investment and action across public bodies to secure cost-effective delivery of resilient and sustainable catchments.
Chaired by the Cairngorms National Park Authority and with a programme board comprising Scottish Water, SEPA, NatureScot, FLS, Scottish Forestry and Scottish Government, pilot work is underway in the River Dee and the Angus Glens / South Esk catchments. The work will engage landowners, farmers and operators across the catchments to implement improved water and land management, and nature-based approaches to deliver resilience whilst also improving biodiversity and capturing more carbon in nature.
And our Low Carbon Concrete Collective (LCCC) with Network Rail, SSE, Scottish Power and Transport Scotland is continuing to make progress. The Collective was established in 2022 to accelerate the development and adoption of the next generation of low carbon concrete in Scotland and is progressing the design and pilot of a product called Recycl8.
Recycl8 – Innovation in Construction
If you would be interested in partnering with us for example to:
please contact our Net Zero lead Elise Cartmell.
To encourage knowledge sharing, our Net Zero Heroes network continues to go from strength to strength. We have around 90 people meeting together regularly from Scottish Water and our supply chain partners to share best practice. It includes people who have enabled and implemented carbon savings and carbon capture opportunities and others who have improved net zero reporting or delivered an exemplary project to help us with our sustainability ambitions. We have also initiated work with some of our key equipment suppliers to better understand how their products will decarbonise over time. This has allowed us to update our pathway to net zero investment emissions.
We are continuing to link in with community groups with woodland planting for our “Wee Woodlands”. In the Scottish Borders, Scottish Water partnered with the Woodland Trust to deliver a community and volunteer planting day at Knowes Dean Reservoir. Whilst at Cocksburn Reservoir in the Forth Climate Forest area over 50 volunteers came together to plant 1,300 native broadleaf saplings.
Volunteers Plant Hundreds of Trees at Borders Reservoir
Scottish Water and Volunteers plant hundreds of saplings at Cocksburn Reservoir
PROGRESS IN YEAR
During 2025/26 we made good progress across all four key strategic activity areas of our routemap:
BECOMING MORE
ENERGY EFFICIENT
Saved 4.51GWh of electricity in our water (0.28GWh) and wastewater (4.23GWh) services through 40 energy efficiency projects through pump refurbishment, variable speed drive (VSD) installations, air source heat pumps and LED lighting projects. The installation of air source heat pumps has also reduced the requirement for heating oil and we hope to have installed over 100 by the end of our current regulatory period (March 2027).
Completed 11 renewable energy projects with a generating capacity of 3.88GWh.
Case study – Solar Panels Power Up Forfar site
Case study – £1 million solar scheme completed in Fife
Case study – Solar Scheme Helps Power Fresh Water for Borders Homes
USING LOWER-CARBON
ENERGY PRODUCTS
Added a further 24 electric vehicles to our fleet, bringing our fleet to 212 electric vans and 562 electric cars supported by 475 charging points across our sites.
Deployed our first fully electric HGV tanker – one of the first in use in the UK.
Case study – HGV First fully electric tanker joins our fleet.
Deployed sustainable HVO, which has c.90% lower carbon emissions compared with diesel, with our investment programme partners and within our Scottish Water fleet and standby generators. Installed three HVO fuelling stations at Daldowie (Glasgow), Henderson Drive (Inverness) and Juniper House (Edinburgh) focused on refuelling our tanker and sampling courier fleet as these vehicles are not yet able to transition to electric.
Implemented a recycled aggregate framework for use in excavations, service reservoir overburden and other suitable construction applications, helping to reduce reliance on virgin materials and support a more circular approach to project delivery. By making recycled aggregate easier to specify and procure, the framework enables delivery teams to cut embodied carbon, reduce waste sent off site and lower transport impacts through more efficient reuse of materials where technically appropriate.
Continued the implementation of our low carbon kiosk framework with Ross Shire Engineering, Quinnshield and Capvond with 34 sites now using kiosks made of wood saving over 860 tCO2e.
embracing low
carbon construction
Appointed supply chain partners to our new Structural Steel and Fabrication Services framework to ensure that Scottish Water can now access steel manufactured using Electric Arc Furnace (EAF) technology. Steel is fundamental to our operational and capital programmes, yet conventional production methods carry a high embodied carbon impact. By enabling the use of EAF‑manufactured steel, we are significantly reducing, by around 70% embodied carbon, strengthening the resilience of our low carbon supply chain.
Signed the Advance Market Commitment for concrete which will see 20,000 cubic metres of low carbon concrete being procured over five years (c. 30% of annual usage).
storing away emissions that
cannot be avoided
Restored 478 ha of peatland predominantly in our Backwater and Loch Katrine water catchments capturing over 3,700 tCO2e.
Case study – Restoring natural carbon stores.
Planted 215 ha of native broadleaf woodland with oak, alder, hawthorn, rowan and birch trees and completed drone seeding at Talla Water Woods.
Case study – Pioneering Drone Technology Seeds Millions of Trees at Talla Reservoir.
Confirmed the establishment of 35 ha of natural woodland regeneration predominantly at Loch Katrine.
These activities improve source water quality and biodiversity and support our catchments becoming more resilient to climate change impacts.
KEY FUTURE OBJECTIVES
FOR YEAR 7: 2026/27
Year 7 in our routemap brings us to the end of our current regulatory Strategic Review of Charges 2021 – 2027 period (SRC21). Our plan is to continue our delivery focus on carbon reductions and to prepare activities for our next regulatory period Strategic Review of Charges 2027 – 2033 (SRC27).
In particular we will:
FOR OUR NEXT REGULATORY PERIOD 2027-2033
We will act across all key strategic goals in our routemap to:
Minimise Operational Emissions
Minimise Investment Emissions
Increase Carbon Capture on our land
GREENHOUSE GAS EMISSIONS BY SOURCE
Our operational greenhouse gas emissions – our carbon footprint – was 207,243 tCO2e compared with 223,214 tCO2e in 2024/25. The emissions for 2025/26 have been updated from the earlier reported number after a review of population data.
Reductions were driven by a lower carbon intensity in grid electricity, alongside continued energy efficiency improvements, with around 4.5GWh of energy savings delivered during the year. Further reductions were achieved through increased use of lower-carbon HVO as an alternative to diesel.
We expanded the boundary of our reported operational emissions to include emissions linked to the chemicals used in our water and wastewater treatment processes. These are part of “Scope 3” emissions – indirect emissions generated through our supply chain, including the production and transport of materials we purchase and use to deliver services. This change reflects updated Scottish Government statutory guidance for public bodies, which now requires organisations to report a broader range of indirect emissions alongside those generated directly from their own operations.
By including emissions associated with chemicals used in our water and wastewater treatment processes this added an estimated 18,945 tCO2e to our operational footprint. As a result, the total reported operational footprint for 2025/26 was 226,188 tCO2e. With 2025/26 now established as the baseline year for these additional emissions, we will begin work to identify opportunities to reduce and optimise chemical use, including the transition to lower-carbon alternatives.
As in previous years the footprint was successfully verified externally to ISO 14064-1.
The continued greening of the grid coupled with increased energy efficiency and renewables delivery has made a good contribution to our progress, but at 49% of emissions, electricity remains our biggest source.
At the same time, our emissions profile is becoming more complex. While grid electricity remains the single largest contributor, for the first time it now accounts for just under half of our overall emissions footprint. At 24%, process emissions from wastewater treatment are the next biggest source.
Process emissions cover the methane and nitrous oxide associated with the wastewater service. During 2025/26, the UK Greenhouse Gas inventory adopted new emission factors for wastewater treatment process emissions. These are significantly higher than used previously, and the UK water sector is presently working to adopt these factors. We expect this could see an increase in the carbon associated with these emissions. We will begin reporting these updated factors from 2026/27.
This is expected to have a material impact on the pathway to achieve net zero. This does not mean that the goal is not achievable. It means that we will need to undertake further work into the pathways, technologies and opportunities to mitigate emissions in future investment periods.
PROGRESS UPDATE
We have highlighted key milestones on the way to net zero in our routemap which covers all aspects of our emissions. Our milestones are supported by a range of actions and activities to build capacity and capability which we undertake to deliver specific goals over defined timescales to reach net zero.
Progress across our goals can be viewed in the sections below.
Electricity consumption is still our largest single source of emissions at 49%. We must reduce our consumption to reduce emissions and increase financial benefits, while enabling us to support other goals such as generating all the electricity we consume.
GOAL: Reducing our consumption of electricity – Goal 20% by 2040
GOAL: 100% of energy used is our own or hosted renewables by 2040
Process emissions, particularly nitrous oxide (N2O), remains the most challenging area for the water sector to address, requiring a focus on the science, measurement and management of emissions, as well as on technologies to reduce or eliminate the production of emissions.
GOAL: 20% reduction by 2040
Laighpark Wastewater Treatment Works – reducing nitrous oxide emissions.
Reducing our reliance on fossil fuels across our sites is a key part of getting to net zero. This has proven a complex matter as we rely heavily in fuels for emergency and stand-by generators and extreme weather events are becoming more frequent and intense.
38.2GWh of energy was generated from bioresources in 2025/26 by Scottish Water and PFI partners.
GOAL: 100% reduction in gas and fuel oil consumption
Key Achievements:
Our fleet recorded travel of 23.2 million miles last year delivering services for customers. This is a slight increase on the previous year where improved telematics were fitted to all long-term hire vehicles for the first time.
Our strategy aims to minimise the miles we travel and find zero emissions ways to travel.
GOAL: 50% reduction in the distance we travel
GOAL: 100% Zero Emissions Fleet
We were the first UK water company to include investment emissions within our Beyond Net Zero ambition, recognising that the carbon associated with the design, construction and maintenance of our assets is one of our largest sources of emissions. We continue to embed carbon management throughout project development and delivery, maintaining PAS2080 certification and strengthening the application of the Five Client Carbon Commitments across our capital programme.
GOAL: 75% reduction in carbon intensity of investment
GOAL: 75% reduction in carbon intensity
Achieving our ambition to reduce the carbon intensity of investment by 75% will only be possible through strong collaboration with our delivery partners and supply chain. We continue to work closely with suppliers, contractors and industry partners to accelerate the adoption of lower-carbon materials, innovative construction techniques and new technologies that reduce emissions across the whole asset lifecycle. Through early engagement, shared objectives and a focus on carbon-informed decision making, our supply chain is helping to embed lower-carbon solutions into project design, procurement and delivery.
Our delivery partners are playing a key role in identifying and implementing opportunities to reduce embodied carbon through material reuse, design optimisation and the adoption of lower-carbon products. Suppliers are supporting the transition to lower-carbon concrete, greater use of recycled and reused materials, alternative fuels, electric plant and emerging zero-emission construction technologies. These collaborations are helping to demonstrate that carbon reduction can be delivered alongside improvements in cost, efficiency and project outcomes.
By continuing to strengthen relationships with our supply chain, share innovation, support trials and pilots, and create confidence for investment in low carbon products and technologies, we are helping build the capability and capacity needed to deliver sustained reductions in the carbon intensity of investment and support our Beyond Net Zero ambition.
Examples of supply chain collaboration:
Glenkiln Siphon Project – Delivering Carbon Reduction Through Collaborative Innovation.
Across the 24,000 ha of our land, we can contribute to the natural, social and economic sustainability of Scotland’s landscape by working to increase carbon storage and biodiversity.
GOAL: Improve carbon dioxide storage on our land to support net zero emissions
Electricity consumption is still our largest single source of emissions at 49%. We must reduce our consumption to reduce emissions and increase financial benefits, while enabling us to support other goals such as generating all the electricity we consume.
GOAL: Reducing our consumption of electricity – Goal 20% by 2040
GOAL: 100% of energy used is our own or hosted renewables by 2040
Process emissions, particularly nitrous oxide (N2O), remains the most challenging area for the water sector to address, requiring a focus on the science, measurement and management of emissions, as well as on technologies to reduce or eliminate the production of emissions.
GOAL: 20% reduction by 2040
Laighpark Wastewater Treatment Works – reducing nitrous oxide emissions.
Reducing our reliance on fossil fuels across our sites is a key part of getting to net zero. This has proven a complex matter as we rely heavily in fuels for emergency and stand-by generators and extreme weather events are becoming more frequent and intense.
38.2GWh of energy was generated from bioresources in 2025/26 by Scottish Water and PFI partners.
GOAL: 100% reduction in gas and fuel oil consumption
Key Achievements:
Our fleet recorded travel of 23.2 million miles last year delivering services for customers. This is a slight increase on the previous year where improved telematics were fitted to all long-term hire vehicles for the first time.
Our strategy aims to minimise the miles we travel and find zero emissions ways to travel.
GOAL: 50% reduction in the distance we travel
GOAL: 100% Zero Emissions Fleet
We were the first UK water company to include investment emissions within our Beyond Net Zero ambition, recognising that the carbon associated with the design, construction and maintenance of our assets is one of our largest sources of emissions. We continue to embed carbon management throughout project development and delivery, maintaining PAS2080 certification and strengthening the application of the Five Client Carbon Commitments across our capital programme.
GOAL: 75% reduction in carbon intensity of investment
GOAL: 75% reduction in carbon intensity
Achieving our ambition to reduce the carbon intensity of investment by 75% will only be possible through strong collaboration with our delivery partners and supply chain. We continue to work closely with suppliers, contractors and industry partners to accelerate the adoption of lower-carbon materials, innovative construction techniques and new technologies that reduce emissions across the whole asset lifecycle. Through early engagement, shared objectives and a focus on carbon-informed decision making, our supply chain is helping to embed lower-carbon solutions into project design, procurement and delivery.
Our delivery partners are playing a key role in identifying and implementing opportunities to reduce embodied carbon through material reuse, design optimisation and the adoption of lower-carbon products. Suppliers are supporting the transition to lower-carbon concrete, greater use of recycled and reused materials, alternative fuels, electric plant and emerging zero-emission construction technologies. These collaborations are helping to demonstrate that carbon reduction can be delivered alongside improvements in cost, efficiency and project outcomes.
By continuing to strengthen relationships with our supply chain, share innovation, support trials and pilots, and create confidence for investment in low carbon products and technologies, we are helping build the capability and capacity needed to deliver sustained reductions in the carbon intensity of investment and support our Beyond Net Zero ambition.
Examples of supply chain collaboration:
Glenkiln Siphon Project – Delivering Carbon Reduction Through Collaborative Innovation.
Across the 24,000 ha of our land, we can contribute to the natural, social and economic sustainability of Scotland’s landscape by working to increase carbon storage and biodiversity.
GOAL: Improve carbon dioxide storage on our land to support net zero emissions
ENABLERS
We cannot achieve our ambitious goals alone and we assume that required future investment funding is available. On our journey to net zero there are some key enabling activities which we have progressed in the last year.
PEOPLE
GOVERNANCE
POLICY AND REGULATION
We continue to share and develop best practice with partners and stakeholders and Scottish Water takes an active role in a number of external groups addressing the climate and nature crises including:
PROCUREMENT
INNOVATION
NET ZERO RESEARCH AND INNOVATION
This section provides an overview of projects underway during 2025/26.
AMMONIA RECOVERY TRIAL
Progression of a 5m3/day ammonia recovery technology has continued with programme and contracts being finalised. Started on site in Autumn 2025.
We will test the Ammonium sulphate liquid produced for all European fertiliser regulation requirements to ensure the quality of the output material meets specifications required and can potentially be reused.
NITROUS OXIDE CAPTURE AND DESTRUCTION TECHNOLOGY
We are planning a trial of an activated sludge plant cover and destruction technology with Powerplastic and Suez. This will utilise an odour control style cover which collects the off gases and then actively blows the gases into a photocatalytic destruction box with tuneable UV and catalyst concentration.
Preliminary designs complete and final designs underway with the potential to capture ? tonnes CO2e.
DIGITAL AND ANALYTICAL TOOLS – METHANE MEASUREMENT AND LiDAR
A short scale trial for methane leak identification and whole site quantification has been undertaken utilising QLMs technology on a trailer.
This trial allowed Scottish Water to identify areas for potentially high-level emissions which were in line with assumptions made prior to the trial.
DIGITAL AND ANALYTICAL TOOLS – LiDAR TO EXAMINE NATURAL REGENERATION OF WOODLAND
Completed a LiDAR (Light Detection and Ranging) study with the Hydro Nation Chair to monitor natural regeneration of woodland at Loch Katrine.
This study examined tree cover greater than 1.5m above ground, across > 500 ha of targeted sites in the region of Glen Gyle at the head of Loch Katrine.
MATERIALS RESEARCH
Concrete Collective (LCC) with Network Rail, SSE, Scottish Power and Transport Scotland is continuing to make progress. The Collective is progressing the design and pilot of new concrete materials including:
HYDROGEN PRODUCTION
Supported by the Scottish Government, Scottish Water Horizons have been collaborating with the NHS to establish whether waste water heat recovery from Scottish Water’s sewerage network can be utilised to help heat NHS facilities to reduce their carbon footprint. This is showing positive results and work is ongoing to carry out flow and temperature measurements to establish the available energy. One site has progressed to the stage of carrying out a detailed engineering study.
Progression of a 5m3/day ammonia recovery technology has continued with programme and contracts being finalised. Started on site in Autumn 2025.
We will test the Ammonium sulphate liquid produced for all European fertiliser regulation requirements to ensure the quality of the output material meets specifications required and can potentially be reused.
NITROUS OXIDE CAPTURE AND DESTRUCTION TECHNOLOGY
We are planning a trial of an activated sludge plant cover and destruction technology with Powerplastic and Suez. This will utilise an odour control style cover which collects the off gases and then actively blows the gases into a photocatalytic destruction box with tuneable UV and catalyst concentration.
Preliminary designs complete and final designs underway with the potential to capture ? tonnes CO2e.
A short scale trial for methane leak identification and whole site quantification has been undertaken utilising QLMs technology on a trailer.
This trial allowed Scottish Water to identify areas for potentially high-level emissions which were in line with assumptions made prior to the trial.
Completed a LiDAR (Light Detection and Ranging) study with the Hydro Nation Chair to monitor natural regeneration of woodland at Loch Katrine.
This study examined tree cover greater than 1.5m above ground, across > 500 ha of targeted sites in the region of Glen Gyle at the head of Loch Katrine.
Concrete Collective (LCC) with Network Rail, SSE, Scottish Power and Transport Scotland is continuing to make progress. The Collective is progressing the design and pilot of new concrete materials including:
Supported by the Scottish Government, Scottish Water Horizons have been collaborating with the NHS to establish whether waste water heat recovery from Scottish Water’s sewerage network can be utilised to help heat NHS facilities to reduce their carbon footprint. This is showing positive results and work is ongoing to carry out flow and temperature measurements to establish the available energy. One site has progressed to the stage of carrying out a detailed engineering study.
INTRODUCTION
TRANSFORMATION
ELECTRICITY
PROCESS
EMISSIONS
GAS &
FUEL OIL
TRANSPORT
& TRAVEL
INVESTMENT
STORING
CARBON
A novel end of pipe nitrous oxide destruction test bed has been installed at Hawick Wastewater Treatment Works with first trials of photocatalysis undertaken. Initial results have demonstrated low efficacy but onsite checks are being completed to establish the cause and to see if this can be improved.
Primarily focused on adaptation, Scottish Water recently took on the co-chair role for the UK wide group that brings together key stakeholders in the sector with agencies such as the UK Climate Change Committee, regulators and government. During 2025/26, Scottish Water contributed to outputs around catchment management for carbon, nature and climate resilience, and is presently focused around the development of policy advice for the sector on climate resilience.
May 2025 saw the formal launch of the CRIS organisation, co-chaired between Scottish Water and Network Rail, bringing together key water, energy, transport, communications and other sectors with key interdependencies. Primarily focused on climate resilience, this will also build engagement in how we make long term, sustainable decisions across interdependent infrastructure to support resilient, low carbon outcomes.
For the past 5 years Scottish Water has vice-chaired the Sustainable Scotland Network of public bodies in Scotland. The SSN has over 140 public bodies as part of its membership, including all Local Authorities and key public agencies in Scotland. Part funded by Scottish Government and Local Authorities the network develops and shares good practice in carbon, climate and sustainable development, and in 2025/26 was awarded the contract to manage the annual reporting of performance on carbon and climate change mandated for all public bodies in Scotland.
During 2025/26, the Scottish Government published the Statutory Guidance to Scottish public bodies on compliance with the duties set out in the Climate change Act. This was developed with SSN, and Scottish Water made significant contributions to the sections on adaptation, embodied emissions and land carbon management.
Since launching in 2018, the network has saved the equivalent of 21.3 million single-use 330ml plastic bottles – with 6.5 million of those saved in the last year alone. We now have 132 taps, from Lerwick, Shetland in the North to Kirkcudbright, Dumfries & Galloway in the South.
We continue to inspire young responsible water citizens through our Generation H2O programme. This year 626 teachers registered across 300 schools engaging 55,575 young people through downloaded content. This was further enhanced with 60 facilitated school visits by Scottish Water volunteers, making a difference in classrooms across Scotland. To date 43% / 1,091 of Scottish schools have registered for Generation H2O reaching 114,141 young people.
Working in partnership with Aberdeen Science Centre, Dundee Science Centre, Dynamic Earth, Glasgow Science Centre and Science Skills Academy, over 2,400 young people have engaged in our interactive Water Cycle Workshop which inspires curiosity, Science, Technology, Engineering and Maths (STEM) skills and responsible water citizens. 82% of pupils learnt something new through the workshop and 76% of pupils increased their knowledge of ways to save water.
Feedback told us that the funded workshops for some schools meant the difference between being able to go on an out of school trip, or not. Teachers also said:
“The water cycle experiment was really engaging with a lot of hands-on resources that the pupils really enjoyed working with.”
“It was fun and interactive while also letting the children learn something new.”
Engaging communities has remained an important part of Scottish Water’s woodland creation programme. During 2025/26, we continued to engage with key stakeholders and communities around our proposed plans for woodland projects across the country, including at Talla Reservoir where community feedback helped inform the development of our proposals.
Alongside this, volunteer tree-planting events such as those at Knowes Dean and Cocksburn reservoirs enabled local people, environmental partners and Scottish Water employees to make a direct contribution to woodland creation projects.
By involving communities in hands-on planting activities, these projects helped build understanding of how woodland creation supports biodiversity, protects water quality and captures carbon as part of Scottish Water’s journey to net zero.
Through the Water Resilient Dundee partnership, Scottish Water has worked alongside Abertay University, local schools and community groups in the St Mary’s area of Dundee to build understanding of sustainable drainage, flood resilience and nature-based solutions. Engagement was centred around St Mary’s Community Centre, St Andrew’s Primary School and Craigowl Primary School, helping pupils and local residents learn how natural features can help manage rainwater and support biodiversity.
Rather than relying on traditional consultation events, the Scottish Government funded project embedded engagement within school programmes and community centre events. This enabled Scottish Water to reach a wider audience and make climate adaptation and rainwater management more accessible and relevant to the community, ahead of larger-scale work planned with partners through the Strathmartine Connections project.
As part of the programme, rainwater planters, wetlands, weather stations, outdoor learning features and rain gardens were developed with schools and community users, supporting STEM learning while demonstrating practical approaches to managing rainwater and creating greener, more resilient neighbourhoods.
The Glenkiln Siphon project demonstrates how early collaboration between Scottish Water, its delivery partner and the wider supply chain can unlock significant carbon reductions whilst continuing to deliver essential water infrastructure. The project team challenged traditional pumping approaches and applied the principles of PAS2080 carbon management to identify a lower-carbon solution from the earliest stages of project development.
Rather than focusing solely on material substitution or construction efficiencies, the project team considered how the overall solution could be redesigned to minimise emissions. An alternative siphon solution was developed that reduced the need for more carbon-intensive construction activities and temporary pumping arrangements. This approach demonstrated the value of considering carbon alongside cost, risk and performance when making project decisions.
The project also serves as a practical example of the PAS2080 hierarchy in action, demonstrating that the greatest carbon savings are often achieved by avoiding emissions through better design rather than simply reducing emissions from construction activities. The success of Glenkiln has helped showcase the benefits of embedding carbon management into decision-making processes and provides a model for future projects seeking to reduce whole-life carbon emissions across the capital programme. The lessons learned continue to support wider efforts to integrate low-carbon thinking into project development, procurement and delivery, helping Scottish Water and its partners move towards the target of significantly reducing the carbon intensity of investment.
Key Outcomes
Scottish Water’s first fully electric HGV has hit the streets of Glasgow to provide waste water services to customers in the city.
The tanker represents a key milestone in the publicly owned utility’s transition of its fleet to net zero, joining 187 fleet vans, and 500 fully electric cars delivered.
The vehicle, which can charge at 240kW per hour and be fully powered in under three hours, will be operated during the day and charged overnight. It is the first in the UK to be delivered by Scania.
Mark Hunter, Development Services General Manager at Scottish Water, said: “We did a pilot several months ago working with all the teams involved in operating the tanker, to make sure that this vehicle would be fit for purpose.
“It is vital that as well as helping Scottish Water reach its net zero targets, that it is a functional vehicle for the teams that use it and can deliver what they need – which I’m very pleased to say it does.”
Scottish Water Fleet Manager, Elaine Pringle, said: “The addition of our first fully electric HGV to our fleet is a key milestone in our transition journey, helping us to make the leap from decarbonising the smaller vehicles used across Scottish Water to focusing on the next steps that we need to take in order to reach net zero.
“There was a lot of work done to ensure that we ended up with a vehicle that the waste water team could have confidence in using on a daily basis and I’m delighted to see the tanker now in operation and helping to deliver vital services to our customers in Glasgow.”
In addition to the electric vehicles on its fleet, Scottish Water has installed 374 electric vehicle charging points across the country which are increasingly using renewable energy generated on sites.
It has also begun trialling the use of hydrotreated vegetable oil (HVO) in its commercial vehicle fleet.
Laighpark Wastewater Treatment Works was selected for a short process optimisation trial to test whether reducing dissolved oxygen (DO) setpoints could lower nitrous oxide emissions without affecting compliance or treatment performance.
Based on N2ORisk DSS insights (a software platform from Cobalt Water Global), the DO setpoint was reduced to a target of around 1.8 mg/l, within a 1.5–2.0 mg/l range, from 27 January to 11 February 2026. The site was closely monitored before, during and after the change.
The clearest benefit was seen in at the beginning of the aeration part of the process, where N₂O emissions reduced by around 30% during the effective mitigation period. The latter section of the aeration zone showed a smaller reduction of around 20%, with fewer high-DO risk peaks and more stable performance. When extrapolated against 2025 baseline emissions, the trial indicated a potential reduction of around 47 tonnes CO₂e per year, equivalent to a 27% overall reduction.
No negative impact on compliance, final effluent ammonia or energy use was identified during the trial. The results support extending the approach through longer and seasonally repeated trials, with monthly monitoring and DO adjustments to reflect changing process conditions.
Scottish Water has completed a UK-first drone seeding trial at Talla Water Woods, working with forestry delivery partner Bell Ingram, Autospray Systems and Anglia Ruskin University to explore innovative ways of restoring woodland in challenging upland terrain. The trial, delivered in November 2025, used a beyond-line-of-sight drone licence for drone seeding for the first time in the UK. Despite variable weather and difficult high-elevation conditions, Autospray Systems successfully seeded 20 ha as part of Scottish Water’s wider ambition to increase woodland cover across the 300 ha site to more than 200 ha over the next three years. Seeds pelletised by Anglia Ruskin University were used to support germination and improve dispersal, with a mix of approximately 50% rowan and 50% birch chosen for their suitability as colonising species. The project will continue to be monitored to assess seedling germination and survival rates, supporting future decisions on woodland creation and restoration. The work forms part of a wider multi-method approach at Talla Water Woods and aligns with neighbouring landscape restoration efforts, including those led by the Borders Forest Trust.
A peatland restoration programme at Backwater Reservoir in Angus is delivering large-scale environmental and operational benefits.
More than 338 ha of degraded peatland have been restored across the site to date, with further phases planned to extend this to over 500 ha. This work is helping to reinstate peatland as a functioning carbon store, reducing emissions associated with degraded soils while enhancing biodiversity and ecosystem health. Beyond carbon, the restoration plays a critical role in water management. By improving the ability of peatland to retain water, the project helps to slow runoff during periods of heavy rainfall and reduce the amount of dissoved organic carbon entering raw water sources.
This in turn supports more efficient treatment processes, reducing energy demand and improving overall system performance.
Delivering work at this scale presents challenges, including operating in remote and environmentally sensitive locations and managing complex hydrological conditions. However, the long-term benefits–both environmental and operational–make peatland restoration a key component of Scottish Water’s net zero and climate resilience strategy.
Scottish Water’s first fully electric HGV has hit the streets of Glasgow to provide wastewater services to customers in the city.
The tanker represents a key milestone in the transition of our fleet to net zero, joining 187 fleet vans, and 500 fully electric cars delivered.
The vehicle, which can charge at 240kW per hour and be fully powered in under three hours, will be operated during the day and charged overnight. It is the first in the UK to be delivered by Scania.
In addition to the electric vehicles on our fleet, Scottish Water has installed 374 electric vehicle charging points across the country which are increasingly using renewable energy generated on sites.
We have also begun trialling the use of hydrotreated vegetable oil (HVO) in our commercial vehicle fleet.
A new solar scheme is now helping to power essential water services in the Scottish Borders, helping to lower operational costs and supporting Scottish Water’s drive to cut carbon emissions.
The £371,000 investment has seen the installation of 450 tank-top mounted solar panels at Roberton Water Treatment Works near Hawick, which will generate around 0.21GWh of green electricity annually.
65% of the energy generated will be used directly on site, meeting a quarter of the site’s total energy demands. The surplus is exported to the national grid, making renewable energy available to other customers in the region.
This investment will not only reduce the operational costs of running the Roberton site but will also provide resilience against the volatility of grid electricity prices, ensuring lasting value for Scottish Water’s customers for over 30 years.
In addition to the financial savings, the project will cut carbon emissions by around 43 tonnes of CO2 equivalent each year, making the water treatment process at Roberton less carbon intensive and bringing the publicly-owned utility company closer to its goal of net zero emissions by 2040.
The project has been led by Scottish Water Horizons and delivered by renewables specialists R&A Group.
A £1 million solar scheme is now complete at a Scottish Water Horizons’ owned facility linked to Levenmouth Wastewater Treatment Works in Fife.
Over 1,700 ground mounted solar panels have been installed at the site in Cowdenbeath, which safely receives and stores commercial liquid waste before transferring it to the wastewater treatment works for treatment and disposal.
The project is expected to generate 0.53 GWh of green electricity a year, 60% of which will be used on site to meet 29% of the site’s total energy needs and help to reduce operating costs. The other 40% will be exported to the grid.
The system, which was designed to ensure both environmental and financial value, will continue delivering savings for over 30 years – providing resilience against the volatility of grid electricity prices.
It will also save around 109 tonnes of carbon dioxide equivalent each year, the same as flying from Edinburgh to New York and back 222 times, making the treatment process at the site less carbon intensive and helping Scottish Water get closer towards meeting its goal of net zero emissions by 2040.
The project has been led by Scottish Water Horizons and delivered by renewables specialists Absolute Solar and Wind.
A Scottish Water site in Forfar is now partially powered by renewable energy after more than 600 solar panels were installed on land at the treatment works.
A total of 18.5% of the power needed to run Forfar Wastewater Treatment Works is now provided by solar energy, with the 631 ground mounted panels producing around 0.23GWh of power each year.
The project will help to lower operational costs at the site, provide resilience against the volatility of grid electricity prices and support Scottish Water’s drive to cut carbon emissions.
Around 63 tonnes of carbon dioxide equivalent will be saved each year by using the onsite renewable energy – the same as 35 return flights between Aberdeen and New York.
The project has been led by Scottish Water Horizons, the commercial subsidiary of Scottish Water, and delivered by OCS Energy Services.
Over 50 volunteers worked together to plant hundreds of native broadleaf saplings at a popular Stirlingshire reservoir.
Over the course of three days, the volunteers – including Scottish Water staff, members of the public and employees from local company iGii – planted around 1,300 oak, hawthorn, birch, rowan, hazel and alder saplings on land surrounding Cocksburn Reservoir.
The new scheme forms part of Scottish Water’s wider woodland creation programme, which aims to improve biodiversity and lock up carbon emissions, while also helping protect source water quality against climate change at operational reservoirs across the country.
Once complete, the Cocksburn scheme will see over 4,000 saplings planted over a 2.5 hectare area at the reservoir. Over the next 60 years, it is estimated that the new woodland will capture around 1,350 tonnes of carbon dioxide equivalent – the same as 364 return flights between Glasgow and Tokyo.
The Low Carbon Concrete Collective is working on using the RECYCL8 product on Scottish Water manholes (see photos), Network Rail cable troughs and foundations with SSE.
Photos are of low carbon RECYCL8 concrete manholes in production.
Volunteers came together at a Scottish Water reservoir in the Borders to plant hundreds of native trees at the site.
Over 20 volunteers from the local community and Scottish Water took part in the event, which was led by the Woodland Trust at Knowes Dean Reservoir near Galashiels, with around 300 saplings being planted ranging from downy birch and hazel to holly and rowan.
The work will improve biodiversity in the area by helping to link up vital habitats, acting as a stepping stone for wildlife movement and providing food, shelter and breeding sites for a variety of species.
The woodland will also help to store carbon and forms part of the wider woodland creation programme that Scottish Water is delivering across the country.
Scottish Water is partnering with the Royal Botanic Garden Edinburgh (RBGE) through its Plants with Purpose programme, a five-year research and innovation initiative exploring how plants and nature-based solutions can help address challenges such as surface water flooding, biodiversity loss and climate resilience in urban areas.
The partnership brings together scientific research, practical trials and public engagement to improve understanding of how sustainable drainage systems (SuDS) and other blue-green infrastructure can deliver multiple benefits for people and nature. Through the programme, Scottish Water is supporting collaborative research, site-based demonstrations and monitoring activities that are helping to build the evidence base for more effective nature-based approaches to water management.
Over the past year, RBGE has installed and monitored innovative SuDS Planters within the Edinburgh Garden. These systems slow the flow of rainwater from entering the combined sewer network while providing opportunities to study plant performance and biodiversity benefits. Their performance is continuously monitored using soil moisture sensors and outflow tipping buckets, providing valuable data on how water moves through the system and the volume of runoff diverted from the combined sewer network during rainfall events. The installations also demonstrate nature-based solutions in practice, engaging thousands of visitors and professionals each year.
The partnership also supports research into how different planting approaches influence the performance of rain gardens, including their ability to manage rainfall, support healthy vegetation and enhance biodiversity and place-making. A series of experimental rain gardens in RBGE’s plant nursery is being monitored to assess the contribution of different planting mixes, including turfgrass, herbaceous perennials and shrubs, to the long-term performance of sustainable drainage systems. In parallel, surveys of rain garden sites across central Scotland are helping to establish which plants are being used, how they are performing and the benefits they provide for people and nature.
Findings from this work will contribute to the development of practical guidance and evidence to support the wider adoption of nature-based solutions across Scotland.
By combining research, demonstration and public engagement, the partnership is helping to build the evidence and confidence needed to accelerate the use of nature-based solutions that support climate resilience, biodiversity and sustainable water management.
Hundreds of hectares of native woodland are now regenerating at Loch Katrine as a once-in-a-generation project to transform the landscape above one of Scotland’s most important water sources gathers pace.
The project, delivered in partnership by Scottish Water and Forestry and Land Scotland, will restore more than 4,000 ha of native woodland across the catchment by 2040, helping to protect the water supply for over a million people in Glasgow.
Two years on from the start of delivery, the project is already taking shape on the ground – around 600 ha of native woodland are regenerating on the hills above the loch, alongside 100 hectares of new tree planting and the installation of more than 25km of deer and seed island fencing. Over a million new trees are expected to be growing at Loch Katrine by 2030 as work progresses.
Combining large-scale planting with natural regeneration, it is one of the most ambitious woodland creation programmes in the UK and forms a key part of Scottish Water’s commitment to improve the resilience of vital water sources, tackle the impacts of climate change and enhance biodiversity.
One of UK’s Largest Woodland Projects Takes Shape At Loch Katrine.
Supported by the Scottish Government, Scottish Water Horizons have been collaborating with the NHS to establish whether waste water heat recovery from Scottish Water’s sewerage network can be utilised to help heat NHS facilities to reduce their carbon footprint. This is showing positive results and work is ongoing to carry out flow and temperature measurements to establish the available energy. One site has progressed to the stage of carrying out a detailed engineering study.
Concrete Collective (LCC) with Network Rail, SSE, Scottish Power and Transport Scotland is continuing to make progress. The Collective is progressing the design and pilot of new concrete materials including:
Progression of a 5m3/day ammonia recovery technology has continued with programme and contracts being finalised. Started on site in Autumn 2025.
We will test the Ammonium sulphate liquid produced for all European fertiliser regulation requirements to ensure the quality of the output material meets specifications required and can potentially be reused.
We are planning a trial of an activated sludge plant cover and destruction technology with Powerplastic and Suez. This will utilise an odour control style cover which collects the off gases and then actively blows the gases into a photocatalytic destruction box with tuneable UV and catalyst concentration.
Work has been completed on a £2.3 million solar power and battery energy storage scheme at Howden Water Treatment Works near Selkirk which is set to save around 169 tonnes of carbon annually.
The scheme consists of 2,112 ground-mounted solar panels and 15 racks of batteries to store the power generated – which will meet over a third of the site’s power usage and support Scottish Water’s drive to reach net zero emissions by 2040.
The battery energy storage system, the first of its kind on a Scottish Water water treatment asset and only the second on a Scottish Water site to date, means 100% of the renewable power generated by the scheme can be used on site whenever it is needed.
Recognising the importance of safety in such an innovative project, rigorous measures were implemented including remote fault detection, automatic shutdown systems and fire suppression within the battery cabinets.
A pioneering new type of hydro energy generation scheme is now in place at Whiteadder Reservoir in East Lothian, believed to be the first of its kind in Europe.
The £3million scheme is expected to offset almost a third of the energy used by one of East Lothian’s largest pumping stations, named Hungry Snout, which takes around 32 million litres of water per day to Castle Moffat Water Treatment Works before it goes on to supply most of the East Lothian region with drinking water.
The project allows green energy to be generated whilst also accurately controlling the level of the reservoir during seasonal fluctuations in weather.
Through the use of siphon technology, water is drawn up through the intake and over the top of the dam before running down through the siphon, through the hydro turbine, and back to the natural environment.
The investment at Whiteadder will significantly reduce the carbon emissions from the pumping station, saving approximately 111 tonnes of carbon each year, the equivalent of a passenger jet flying from Edinburgh to Sydney, Australia 40 times.
It is expected to generate 0.82GWh of renewable energy per annum from the 199kW turbine.
The project has been led by Scottish Water Horizons, the public utility’s commercial subsidiary, and delivered by renewable energy specialists Emtec Energy.
A short scale trial for methane leak identification and whole site quantification has been undertaken utilising QLMs technology on a trailer.
This trial allowed Scottish Water to identify areas for potentially high-level emissions which were in line with assumptions made prior to the trial.
Having visual data showing that uncovered sludge tanks and cake pads are a source of significant CH4 emissions will enable the quick wins to be identified and the emissions mitigated to gain the biggest reductions.
The technique can also be deployed for routine leak detection and repair (LDAR).
The results have been shared with the teams responsible for industrial emissions compliance and bioresources teams for decision on whether to deploy at bioresource sites.
Completed a LiDAR (Light Detection and Ranging) study with the Hydro Nation Chair to monitor natural regeneration of woodland at Loch Katrine.
This study examined tree cover greater than 1.5m above ground, across > 500 ha of targeted sites in the region of Glen Gyle at the head of Loch Katrine. A novel approach for surveying woodland regeneration, LiDAR creates highly accurate 3D models and maps, enabling detailed analysis of terrain, vegetation, and infrastructure, crucial for applications like autonomous vehicles, environmental monitoring, and infrastructure planning. The aim of this project was to deliver analysis of woodland regeneration along with efficacy testing of the methodology to capture the required density to determine woodland regeneration.
The approach adopted, conducted over 6 days, used a DJI Matrice 350 Unmanned Aerial System with attachable DJI Zenmuse L2 Lidar payload. Flying at 60m-80m above ground, the LIDAR survey yielded a point cloud density of ~500 returns / m2 . Data was processed using DJI Terra 4.4 and the lidR package (4.1.2) of the R language (4.4.2). Maps and spatial analysis were produced using QGIS Desktop 3.34 and ArcGIS Pro 3.1. The resulting point clouds were filtered for noise, normalised and used to produce a Digital Terrain Model (DTM), Digital Surface Model (DSM) and Canopy Height Model (CHM) at 0.5m spatial resolution.
In total, the survey successfully captured low vegetation across 634 ha, with total canopy cover over the survey area found to be 93.2 ha. The data and evidence resulting from the LiDAR surveys demonstrate that the LiDAR methodology is appropriate and effective for monitoring early woodland creation and re-establishment.
Completed a LiDAR (Light Detection and Ranging) study with the Hydro Nation Chair to monitor natural regeneration of woodland at Loch Katrine.
This study examined tree cover greater than 1.5m above ground, across > 500 ha of targeted sites in the region of Glen Gyle at the head of Loch Katrine. A novel approach for surveying woodland regeneration, LiDAR creates highly accurate 3D models and maps, enabling detailed analysis of terrain, vegetation, and infrastructure, crucial for applications like autonomous vehicles, environmental monitoring, and infrastructure planning. The aim of this project was to deliver analysis of woodland regeneration along with efficacy testing of the methodology to capture the required density to determine woodland regeneration.
The approach adopted, conducted over 6 days, used a DJI Matrice 350 Unmanned Aerial System with attachable DJI Zenmuse L2 Lidar payload. Flying at 60m-80m above ground, the LIDAR survey yielded a point cloud density of ~500 returns / m2 . Data was processed using DJI Terra 4.4 and the lidR package (4.1.2) of the R language (4.4.2). Maps and spatial analysis were produced using QGIS Desktop 3.34 and ArcGIS Pro 3.1. The resulting point clouds were filtered for noise, normalised and used to produce a Digital Terrain Model (DTM), Digital Surface Model (DSM) and Canopy Height Model (CHM) at 0.5m spatial resolution.
In total, the survey successfully captured low vegetation across 634 ha, with total canopy cover over the survey area found to be 93.2 ha. The data and evidence resulting from the LiDAR surveys demonstrate that the LiDAR methodology is appropriate and effective for monitoring early woodland creation and re-establishment.
Scottish Water has piloted an innovative approach to woodland creation through the use of fungal pellets with the aim to produce more resilient forests, increase carbon capture potential and reduce the need for fertiliser.
The Rhizopellets have been used on six of its woodland creation sites which were planted over the 2024/25 season and monitoring will be carried out to establish the impact they have on the success of the projects.
The pellets, produced by Edinburgh-based start-up venture Rhizocore Technologies, utilise native mycorrhizal fungi to create a symbiotic underground nutrient network that helps both trees and fungi to flourish.
They are planted alongside the saplings so that the fungi and tree roots can establish a connection, grow together, and the fungi can provide water and nutrients to the tree.
Often, the sites that have been identified for woodland creation have not had trees on them for some time which means the natural mycorrhiza fungi is no longer sufficiently present at these locations.
Kiosks are an essential part of many of our water and wastewater treatment sites and have traditionally been made from glass-reinforced plastic. One of the very first Timber Modular Build (TMB) kiosks, developed and produced by one of our delivery partners, has been delivered to one of Scottish Water’s sites in Howden Wells, near Selkirk. It was manufactured offsite using wood from Scottish Water forestry.
The structure will be used to house chemical dosing equipment needed at the water treatment works and will reduce embodied carbon by up to 75% compared to traditional kiosks made from glass-reinforced plastic. Additionally, it is fully recyclable.
Prior to delivery to the site, the TMBs are fitted out and commissioned, so they are ready to go immediately once taken to the site. The new timber enclosures also exceed fire resistance regulations, will outlast the 25-year design life of a traditional kiosk, and can be constructed more rapidly.
Our partner won the Gamechanger award for the TMB at the Accelerate to Zero Awards, which recognise the businesses, organisations, and individuals making the biggest contribution to decarbonising the built environment.
More info and photos are here: Innovative timber kiosks helping Scottish Water cut carbon on site – Scottish Water
While Scottish Water is working to transition as much of its fleet as possible to electric vehicles, certain segments—such as 4x4s, HGVs, large vans, and high-mileage vehicles—are not yet suitable for electrification due to current technology limitations, vehicle range, or maintenance infrastructure.
To address this gap and reduce emissions in the near term, Hydrotreated Vegetable Oil (HVO) is being trialled as a low-carbon alternative to diesel. To make refuelling as straightforward as possible for drivers, a reliable network of access points across Scotland is required.
Currently, Scottish Water has access to the following public HVO refuelling locations (Blue Tag): Certas Energy sites in Dumfries, Forfar, Ecclefechan and Highland Fuels site in Lerwick. Additional forecourt options are also being explored, including sites operated by Gulf (a Certas brand), to expand coverage and make HVO more accessible.
Access is also available to a partner refuelling site at Clancy’s Livingston location (Red Tag), which is currently being used by a small number of drivers. Working with partners to share infrastructure and improve availability across combined networks will continue to be progressed.
Refuelling capabilities are in the process of being established at key Scottish Water locations, including: Daldowie, Henderson Drive and Juniper House (Yellow Tag). Work is underway to set up the necessary logistics and access at these sites to support internal HVO use and further reduce environmental impact.
Population Equivalent: 58,834
Type of works: nitrifying activated sludge plant (ASP) using diffused aeration.
Phillipshill is a medium sized waste water treatment works in East Kilbride. Its secondary treatment is split between two phases: Phase A treats 30% of screened sewage and Phase B treats 70% of screened sewage. We are monitoring nitrous oxide (N2O) using liquid phase N2O sensors in both Phase A and Phase B. This allows us to get actual site-wide nitrous oxide emission factors (EF) for reporting rather than using national Carbon Accounting Workbook (CAW) factors. Philipshill is also the first site where we have deployed our flux gas hood monitoring to validate the data we are receiving from the liquid phase probes, ensuring we have reliable data for reporting and to inform our future process emission mitigation actions. We are one of the first water utilities in the UK to deploy gas hoods for process emission validation.
We are now seeing stable monitoring at Philipshill and are able to make some early observations on nitrous oxide at these works whilst we continue to develop more reliable air flow measurement.
Next steps at Philipshill are to solve our air flow measurement challenges and continue to analyse the data so that informed action can be taken once 12 months of baseline data has been gathered. Interventions will be considered for implementation in 2026. In the meantime, a site emission factor will be calculated and compared to the current Carbon Accounting Workbook figure to allow us to determine if we have been over or under-reporting process emissions at this site.
We have worked with two communities in Prestwick and the Craigleith area of Edinburgh to trial a pilot scheme aimed at providing a natural solution to reduce surface water flooding in the areas. Residents who signed up to take part in the trial have had rainwater planters and water butts installed, capturing rainwater that flows off their roof and preventing it from overwhelming the drainage system during periods of heavy rain.
We worked in partnership with a local community group in Aberdeen to provide an improved habitat for wading and farmland birds on Scottish Water land at Inchgarth Reservoir, as well as protecting and enhancing biodiversity at the site.
Alongside Inchgarth Biodiversity Initiative (IBI) of Cults, Bieldside and Milltimber Community Council, and contractor Ground Control, two wader scrapes have now been created on grassland at the site – shallow pools of water which provide important feeding sites for adults and chicks of farmland waders such as Snipe and Jack Snipe.
In addition, a 6,941 m2 area has been tilled and planted up with a winter seed crop which will help attract more birds and pollinating insects to the area, while a number of birch trees have also been planted along the perimeter of the site by IBI volunteers.
We helped save the equivalent of more than 70,000 single use bottles thanks to the presence of our Pop Up Taps at the Royal Highland Show in Ingliston, Orkney Island Games and Water Safety Day at Loch Lomond over the summer, where we made fresh drinking water easily accessible to those attending and encouraged the use of refillable bottles.
More widely, our permanent network of 132 Top Up Taps has served up the equivalent of over 17 million bottles worth of drinking water to customers around the country.
Through our Generation H20 education programme, we have engaged with over 58,000 young people, 942 teachers and 791 schools to date, aiming to inspire them to become part of a movement to celebrate and protect Scotland’s water and become responsible water citizens. 100% of teachers surveyed agreed that students felt motivated to save water after taking part in the programme, while 63% of students surveyed said they had taken action to save water beyond the classroom.
We have carried out engagement with stakeholders and local communities around our plans for woodland creation over the upcoming planting season which span sites across Scotland.
Repairing and maintaining treated Water Storage tanks in our networks across the whole of Scotland is responsible for c. 10% of the spend on our water treatment works and networks each year. Given the repeatability of site set up’s for this work MacKenzie Construction Limited (MCL) investigated the lowest carbon site set up.
Burghmuir treated water storage tank repair in Perth, had a 42 week work programme, MCL adopted – aluminium track panels for the access road, eco welfare units, hybrid power generator, HVO to replace diesel and used a hydrogen powered site security system.
By comparing a traditional site set up with the set up at Burghmuir, MCL achieved a 97% reduction in CO2e emissions saving 126 tCO2e and a £43k reduction in costs. 70% of the site establishment used hybrid power.
This set up is now BAU across our sites.
10 new electric vans have been delivered to Customer Water Services (CWS) and Electrical and Mechanical (E&M) operational teams in Orkney, across Westray, Sanday, Eday, North Ronaldsay and the Orkney Mainland. To support the transition, electric vehicle (EV) charging points have also been fitted at operational sites including Boardhouse Water Treatment Works (WTW) Kirkwall Waste Water Treatment Works (WWTW) and Bu-Point WWTW, with another 5 site installations in progress. All operatives are very pleased with the new EV driving experience and pioneering for the greener environment.
Scottish Water Horizons has delivered an innovative hydropower scheme at Hamilton waste water treatment works. This project signifies a significant leap forward for the industry, achieving several notably milestones. Firstly, it marks the UK’s first mid-process waste water installation which maximises energy potential. It is also Scotland’s first containerised hydropower installation, delivering dual benefits of reducing construction emissions whilst saving time and costs. This project reduces our reliance on imported grid electricity and minimises on-site energy expenses. The scheme is estimated to produce 0.42 GWh of green electricity annually, offsetting approximately 14% of the site’s yearly energy demand and mitigating around 64 tCO2e annually.
This year we achieved a key milestone for our plans to improve carbon capture and biodiversity at Loch Katrine, the source of water for Greater Glasgow. We have been working closely with Forestry and Land Scotland to prepare a 10-year land management plan for the 9500 ha estate around the loch and this has now been submitted to Scottish Forestry for approval.
The plan looks at how we increase tree cover and biodiversity and focuses on natural regeneration using Scottish native trees including birch, rowan, oak and alder. This approach has a minimal impact on the catchment and water quality. We will also be restoring peatland at the site.
The project is set to deliver a 40% increase in biodiversity on the estate and capture nearly a million tonnes of carbon over the next 60 years.
Scottish Water installs many glass reinforced plastic kiosks on its assets to house a wide variety of equipment- from chemical dosing skids to electrical panels. There is a high carbon content in the kiosk- often more than the equipment in the kiosk. Two of our construction partners have been exploring alternative low carbon materials. Three new kiosk types have now been designed and built with low carbon materials and we are starting to deploy them on projects. One is made from recycled plastic bottles, one is made from engineered timber and the third is made from light gauge steel. The carbon reduction ranges from 60 to 85%, depending on the material used and the security rating of the kiosk. As well as being used by Scottish Water, other utility companies are also looking to use them on their projects.
Scottish Water has established a framework for the supply of sustainably sourced hydrotreated vegetable oil that can be used by both Scottish Water and its construction partners. It’s a drop in fuel replacement that reduces emissions by 90% compared to conventional diesel.
Over the last year it has been widely adopted by our construction partners, displacing diesel use in excavators, cranes and other heavy plant. It is also being used to fuel generators to provide power for remote construction sites.
On our water mains rehabilitation programme its adoption is expected to reduce emissions by nearly 30%.
Forest Research are completing a review on woodland creation and water quality and quantity. This project is focusing on Broadleaf woodland creation to help inform current woodland creation and future strategy.
Scottish Water has been a partner in a project, led by the local community and supported by the National Lottery’s Community Fund, to regenerate the site once occupied by Douglas Primary School as a multi-functional greenspace.
Our team worked with the community to incorporate sustainable drainage features in the new park, which store and slowly release the rainwater that falls on surrounding roads and rooftops during storms. This eases pressure on the combined sewer network in the local area, as well as helping to protect the local environment and reduce flood risk from the Dighty Burn. Importantly, the community has been able to realise its wider aims by creating an attractive outdoor space that also provides a home for wildlife; and can be enjoyed for play, relaxation, exercise, events and the growing of food.
Planning is now underway to introduce more sustainable water management measures in the area surrounding the park, with the aim of disconnecting over 40,000m2 of land area from the combined sewer network; and helping to enable the development of more social housing in Douglas. Engagement with the community, including schools and other key stakeholders, is being carried out to help shape the proposals.
Work with the community and Dundee City Council on sustainable drainage for Douglas has helped to inspire the Water Resilient Dundee partnership. This initiative is now pursuing opportunities for more sustainable management of stormwater across the city, reducing flood risk in communities, creating capacity for development and enhancing amenity.
