YEAR FIVE OVERVIEW
We successfully delivered over 10,892 tCO2e of carbon reductions in Year 5 of our Net Zero Routemap (2024/25), through a range of activities such as peatland restoration and energy projects.
These also delivered cost savings, improved source water quality in three catchments, increased biodiversity/natural capital across 858 hectares (ha) (equivalent to 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 4,546 tCO2e to 220,434 tCO2e. This compares to 224,980 tCO2e last year. This reduction was achieved through reduced energy demand alongside our carbon reduction energy efficiency measures and increased on-site renewable energy production. Changes to the emission factors for grid electricity increased over the past year, increasing our footprint by 202 tCO2e.
Our carbon reduction activities are vital as a changing climate is threatening our ability to deliver essential water and waste water 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 have recognised that we need to expand our knowledge and capabilities around the installation of process emission monitors in our activated sludge waste water sites and their data connectivity with our existing digital systems. We have increased our resourcing in this area and have on-boarded a further company to help support monitor installation.
To reinforce the management, continuous improvement and learning required to embed net zero across all we do, we have worked towards successful accreditation this year with the PAS2080 (Publicly Available Specification) for carbon management.
We completed a review of our supply chain for hydrotreated vegetable oil (HVO). HVO is now being used to support carbon emission reductions in the parts of our fleet that are currently unsuitable for EVs due to load or distance factors. The HVO we use is certified as not containing virgin palm oil. Following our review and on-going 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. However, it is taking time to implement and this may mean reductions in our planned renewable programme for the rest of this regulatory period.
Whilst it was a record year for peatland restoration, several projects 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 are now underway with 24 ha woodland planted and over 90 ha of land reached sufficient maturity and density through natural regeneration to be re-classified as native woodland this year. We also restored 55 ha of peatland and working with the Hydro Nation Chair installed innovative peatland restoration monitoring. Loch Katrine Research – Scottish Water
Our partnership with the Royal Botanic Garden Edinburgh on their ‘plants with purpose’ programme is progressing well and our PhD student has now been appointed. They are examining and optimising planting schemes to support carbon reduction in blue-green infrastructure projects such as rain gardens and storm water planters.
In 2024/25, we completed three woodland creation projects in East Renfrewshire and South Lanarkshire (Dunside Water Treatment Works, Glengavel Reservoir and Newton Mearns Waste Water Treatment Works), planting a total of 41 ha within the Clyde Climate Forest. This builds on the 19 ha of woodland already created adjacent to the Clyde Climate Forest boundary. In 2025/26 we have three woodland creation projects planned in the Forth Climate Forest area.
Hydrogen will be an important fuel in the wider Net Zero transition, and water is a key component in the production of hydrogen. To support the growing hydrogen economy, Scottish Water Horizons is working with stakeholders and production companies on over 80 projects across the country with a potential hydrogen capacity of over 7 GW. To provide the most sustainable and economic input source, and to conserve water supplies within the catchment, our preferred water source for hydrogen production is final effluent from our waste water treatment works.
In our commitment to partnership Scottish Water continues to work with the Edinburgh and Glasgow Climate Compact to help to boost climate action.
And our Low Carbon Concrete Collective (LCC) with Network Rail, SSE, Scottish Power and Transport Scotland is continuing to make progress. The Collective was established in 2022 to accelerate the development, availability and adoption of the next-generation of low carbon concrete in Scotland and are progressing the design and pilot of:
We are also progressing with the Advanced Market Commitment for low carbon concrete with Innovate UK.











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 continue to go from strength to strength. We now have approaching 100 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 starting to link in with community groups with woodland planting. We have completed planting days with Friends of the Pentlands at Glencorse successfully planting around 400 native broadleaf samplings and at Roscobie Reservoir with local communities and the Fife Coast and Countryside Trust (FCCT) to plant around 1,600 silver birch, downy birch, oak, elder, hawthorn and crab apple tree saplings across a 1.4 ha area surrounding the reservoir.
Team Effort for Trees at Glencorse – Scottish Water
Volunteers Dig In to Create Native Woodland at Roscobie Reservoir – Scottish Water
We and our partners have been externally recognised for our work receiving three awards in 2024/25.

ICE Scotland Sustainability Champion Award – Ian Watt

Built Environment Smarter Transformation Ross Shire Enginering – Gamechanger Award, Timber Modular Build

WGMB and Scottish Water – Circular Economy MEICA Strategy for Utility Assets – Utility Week Awards 2024
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 have recognised that we need to expand our knowledge and capabilities around the installation of process emission monitors in our activated sludge waste water sites and their data connectivity with our existing digital systems. We have increased our resourcing in this area and have on-boarded a further company to help support monitor installation.
To reinforce the management, continuous improvement and learning required to embed net zero across all we do, we have worked towards successful accreditation this year with the PAS2080 (Publicly Available Specification) for carbon management.
We completed a review of our supply chain for hydrotreated vegetable oil (HVO). HVO is now being used to support carbon emission reductions in the parts of our fleet that are currently unsuitable for EVs due to load or distance factors. The HVO we use is certified as not containing virgin palm oil. Following our review and on-going 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. However, it is taking time to implement and this may mean reductions in our planned renewable programme for the rest of this regulatory period.
Whilst it was a record year for peatland restoration, several projects 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 are now underway with 24 ha woodland planted and over 90 ha of land reached sufficient maturity and density through natural regeneration to be re-classified as native woodland this year. We also restored 55 ha of peatland and working with the Hydro Nation Chair installed innovative peatland restoration monitoring. Loch Katrine Research – Scottish Water
Our partnership with the Royal Botanic Garden Edinburgh on their ‘plants with purpose’ programme is progressing well and our PhD student has now been appointed. They are examining and optimising planting schemes to support carbon reduction in blue-green infrastructure projects such as rain gardens and storm water planters.
In 2024/25, we completed three woodland creation projects in East Renfrewshire and South Lanarkshire (Dunside Water Treatment Works, Glengavel Reservoir and Newton Mearns Waste Water Treatment Works), planting a total of 41 ha within the Clyde Climate Forest. This builds on the 19 ha of woodland already created adjacent to the Clyde Climate Forest boundary. In 2025/26 we have three woodland creation projects planned in the Forth Climate Forest area.
Hydrogen will be an important fuel in the wider Net Zero transition, and water is a key component in the production of hydrogen. To support the growing hydrogen economy, Scottish Water Horizons is working with stakeholders and production companies on over 80 projects across the country with a potential hydrogen capacity of over 7 GW. To provide the most sustainable and economic input source, and to conserve water supplies within the catchment, our preferred water source for hydrogen production is final effluent from our waste water treatment works.
In our commitment to partnership Scottish Water continues to work with the Edinburgh and Glasgow Climate Compact to help to boost climate action.
And our Low Carbon Concrete Collective (LCC) with Network Rail, SSE, Scottish Power and Transport Scotland is continuing to make progress. The Collective was established in 2022 to accelerate the development, availability and adoption of the next-generation of low carbon concrete in Scotland and are progressing the design and pilot of:
We are also progressing with the Advanced Market Commitment for low carbon concrete with Innovate UK.











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 continue to go from strength to strength. We now have approaching 100 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 starting to link in with community groups with woodland planting. We have completed planting days with Friends of the Pentlands at Glencorse successfully planting around 400 native broadleaf samplings and at Roscobie Reservoir with local communities and the Fife Coast and Countryside Trust (FCCT) to plant around 1,600 silver birch, downy birch, oak, elder, hawthorn and crab apple tree saplings across a 1.4 ha area surrounding the reservoir.
Team Effort for Trees at Glencorse – Scottish Water
Volunteers Dig In to Create Native Woodland at Roscobie Reservoir – Scottish Water
We and our partners have been externally recognised for our work receiving three awards in 2024/25.

ICE Scotland Sustainability Champion Award – Ian Watt

Built Environment Smarter Transformation Ross Shire Enginering – Gamechanger Award, Timber Modular Build

WGMB and Scottish Water – Circular Economy MEICA Strategy for Utility Assets – Utility Week Awards 2024
PROGRESS IN YEAR
During 2024/25 we made good progress across all four key strategic activity areas of our routemap:
BECOMING MORE
ENERGY EFFICIENT
Saved 6.28 GWh of electricity in our water and waste water services through over 50 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.
Saved 4.08 GWh at our waste water treatment works, 0.84 GWh at our waste water sludge pumping stations and 1.36 GWh at our water treatment works.
Completed 16 renewable energy projects with a generating capacity of 6.42 GWh.
Installed a European first 0.82 GWh siphon hydro energy scheme at Whiteadder Reservoir in East Lothian.
USING LOWER-CARBON
ENERGY PRODUCTS
Added a further 79 electric vehicles to our fleet giving us 540 in total and expanded our number of charging points to 374.
Deployed sustainable hydro-treated vegetable oil (HVO), which has c. 90% lower carbon emissions compared to diesel, with our investment programme partners and within our Scottish Water fleet and standby generators.
Used recycled aggregate material in excavations and service reservoir overburden.
Implemented our low carbon kiosk framework with Ross Shire Engineering, Quinnshield and Capvond with 15 orders of wood kiosks already placed.
embracing low
carbon construction
Adopted low carbon steel reinforcement (Rebar) products with c. 50% lower CO2e content. Approximately 12% of our construction emissions are associated with Rebar products and therefore a reduction of 5-6% of our total construction emissions is now possible.
Continued with our low carbon concrete pilots producing a pre-cast low carbon concrete manhole ring, a structural foundation and a pre-cast cable trough using a ground granulated blast-furnace slag (GGBS) blend with Recycl8’s bottom ash aggregate using landfill waste. This embraces the circular economy alongside carbon reduction.
Completed a Research and Innovation project on a pump refurbishment trial with WGM, installing 29 refurbished pumps and saving c. 68tCO2e and c. £129,000.
storing away emissions that
cannot be avoided
Restored a record 555 ha of peatland in our water catchments.
Planted 208 ha of native broadleaf woodland with oak, alder, hawthorn, rowan and birch trees.
Confirmed the establishment of 95 ha of natural woodland regeneration at Loch Katrine and other sites.
These activities also improve source water quality and biodiversity and support our catchments becoming more resilient to climate change impacts.
KEY FUTURE OBJECTIVES
FOR YEAR 6 AND YEAR 7 APRIL 2025 – MARCH 2027
Years 6 and 7 in our routemap bring us to the end of our current regulatory period Strategic Review of Charges 2021 – 2027 (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
2024/25 OPERATIONAL EMISSIONS FOOTPRINT
GREENHOUSE GAS EMISSIONS BY SOURCE
Our operational greenhouse gas emissions – our carbon footprint – were 220,434 tCO2e. This compares with 224,980 tCO2e last year.
This significant reduction was achieved due to reduced energy demand alongside energy efficiency measures and increased on-site renewable energy production. Changes to the emission factors for grid electricity increased the impact of our activities by 202 tCO2e.
Our actions are resulting in a continued downward trend for our operational emissions, and we remain on track to deliver net zero before 2040.
To do this we need to progress hosted wind farms on our land, invest in new technology to replace ageing sludge drying facilities and for the electricity grid to decarbonise. These, along with current intelligence on progress of process emissions reductions and forecast increase in carbon capture on our land show that we should achieve operational Net Zero in the mid-2030s.
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 significant contribution to our progress, but at 56% of emissions, electricity remains our biggest source.
At 23%, process emissions from waste water treatment are the next biggest source, which is driving much of the focus on innovation and research to minimise these emissions in the future.
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 56%. 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: 20% reduction by 2040
GOAL: 100% of energy used is our own or hosted renewables by 2040
Process emissions, particularly nitrous oxide (N2O) remain 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
Philipshill Waste Water Treatment Works (WwTW) – you can’t control what you can’t measure.
Reducing our reliance on fossil fuels across all of our sites is a key part of getting to net zero. This has proven a complex matter as we rely heavily on fuels for emergency and stand-by generators and extreme weather events are becoming more frequent and intense.
38.7 GWh of energy was generated from bioresources in 2024/25 by Scottish Water and PFI partners
GOAL: 100% reduction
Key Achievements:
Our fleet recorded travel of 22 million miles last year delivering service for customers. This is a four million increase on the previous year. The reason for this increase is that we moved to a new telematics supplier and telematics were fitted to all long-term hire vehicles, meaning these numbers were added 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 as part of our net zero goal. Now that our operational emissions are reducing investment emissions are now our biggest source of emissions each year.
GOAL: 75% reduction in carbon intensity of investment
GOAL: 75% reduction in carbon intensity
Across the 23,500 hectares 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 56%. 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: 20% reduction by 2040
GOAL: 100% of energy used is our own or hosted renewables by 2040
Process emissions, particularly nitrous oxide (N2O) remain 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
Philipshill Waste Water Treatment Works (WwTW) – you can’t control what you can’t measure.
Reducing our reliance on fossil fuels across all of our sites is a key part of getting to net zero. This has proven a complex matter as we rely heavily on fuels for emergency and stand-by generators and extreme weather events are becoming more frequent and intense.
38.7 GWh of energy was generated from bioresources in 2024/25 by Scottish Water and PFI partners
GOAL: 100% reduction
Key Achievements:
Our fleet recorded travel of 22 million miles last year delivering service for customers. This is a four million increase on the previous year. The reason for this increase is that we moved to a new telematics supplier and telematics were fitted to all long-term hire vehicles, meaning these numbers were added 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 as part of our net zero goal. Now that our operational emissions are reducing investment emissions are now our biggest source of emissions each year.
GOAL: 75% reduction in carbon intensity of investment
GOAL: 75% reduction in carbon intensity
Across the 23,500 hectares 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
CUSTOMERS AND COMMUNITIES
GOVERNANCE
POLICY AND REGULATION
PROCUREMENT
INNOVATION
NET ZERO RESEARCH AND INNOVATION
We have progressed a number of activities across these areas, click each icon to read more.
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.
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.