Overview

Scotland has traditionally enjoyed an abundant and high-quality water supply. Still, climate change is increasing the risk of disruption to both water availability and quality, with implications for public health, community wellbeing and the regional economy. The Highland region is particularly exposed due to its dispersed rural networks, its high dependence on private supplies, and its variable rainfall patterns. Longer dry spells, rising temperatures and extreme rainfall are already placing pressure on small catchments and private sources. At the same time, intense downpours can overwhelm drainage and treatment systems, reducing raw-water quality and increasing operational demands.

By the 2050s and 2080s, these pressures are projected to intensify. Modelling indicates that public supply zones such as Inverness and the Black Isle may experience future supply deficits. At the same time, more variable source-water quality could heighten health risks and undermine service reliability. Adaptation efforts are underway through national investment programmes and catchment management measures, but further coordinated action across Highland linking water management, land restoration and community engagement will be essential to strengthen long-term resilience.

 

What is the current level of risk?

A significant proportion of rural households in the Highland region depend on private supplies, with the Highland Council reporting approximately 2,560 private water supplies serving over 10,000 inhabitants across dispersed settlements.[1] These private sources sit alongside Scottish Water’s regional network, which abstracts from over 420 reservoirs, lochs, rivers, boreholes and springs across Scotland. All Highland communities receive water from sources within their local water resource zone rather than imports from other regions. Scottish Water emphasises that northern and western areas may even see increased available water by 2050, highlighting the regional importance of Highland’s own catchments in maintaining future supply resilience.[2]

Scotland has historically benefited from an abundance of high-quality freshwater resources, yet the reliability of these supplies is increasingly challenged by climatic and environmental change. Scottish Water’s Climate Change Adaptation Plan (2024) shows that, under current conditions, Scotland experiences periodic shortfalls between the volume of water available for public supply and customer demand during dry weather, described by Scottish Water as a “national supply–demand deficit.”[3]

In the Highland region, the resilience of water resources is being tested by a combination of seasonal rainfall variability, increased temperatures, and pressure on small rural supply systems. These systems are typically local networks, often serving only a handful of dispersed households or small settlements, that draw water from small upland reservoirs, springs, boreholes, burns or lochs, and therefore have limited storage capacity and reduced flexibility during prolonged dry periods.[4] SEPA classifies 90% of Scotland’s surface and groundwater resources as in good or better condition, but drought conditions in recent years have exposed vulnerabilities in specific catchments, including those supplying Inverness and the Black Isle.

Declining water quality also represents an immediate concern for public health and wellbeing. Episodes of heavy rainfall, flooding, and sewer overflows have led to temporary reductions in raw water quality and increased risks of microbiological contamination, particularly in catchments affected by land use, diffuse pollution, or algal growth.[5] While current treatment infrastructure and operational responses remain effective, Scottish Water notes that increasing variability in source water quality is placing operational pressure on treatment processes and increasing the costs of maintaining safe, reliable supplies.[6]

 

What is the future level of risk?

Climate projections indicate that pressures on Scotland’s water environment will intensify through the 2050s and 2080s, with prolonged dry periods, higher average temperatures, and greater seasonal rainfall variability. Scottish Water’s Climate Change Adaptation Plan (2024) projects that, without adaptation, the national deficit between water available for supply and customer demand during drought conditions will rise from 60 Ml/d today to around 240 Ml/d by 2050, representing a fourfold increase in shortfall during extended periods of low rainfall.[7]

For the Highland region, the same analysis shows that Inverness could face deficits of 10–25 Ml/d and the Black Isle 1–10 Ml/d by 2050.[8] These projections indicate that Highland will be relatively better off than the most water-stressed regions of Scotland, as Scottish Water notes that some areas in the North and West are projected to increase their available water by 2050, suggesting that the Highlands may experience comparatively lower pressure on overall resource availability than the Central Belt or eastern catchments.[9] Continued population growth in Inverness, coupled with potential new industrial demand (for example, hydrogen production), could, however, place localised strain on resources in some parts of the Highland region.

By the 2080s, the UK Climate Change Risk Assessment (UKCCRA3) identifies a high magnitude of risk to public water supplies across most of the UK, including Scotland, under both 2°C and 4°C warming scenarios, due to more frequent and intense dry periods and increased water demand.[10]

Water quality is also expected to deteriorate under these scenarios. The River Basin Management Plan for Scotland (2021–2027) highlights that climate-driven changes in temperature and rainfall will increase nutrient loading, algal blooms, and episodes of low dissolved oxygen, threatening drinking-water sources and aquatic ecosystems.[11] Evidence from the Centre of Expertise for Waters (CREW) shows that deeper lochs tend to warm more slowly and are less prone to cyanobacterial blooms. Several of the monitored deep lochs in the Highlands, such as Loch Ness, Loch Lochy, Loch Maree and Loch Morar, fall into this category, suggesting that these individual water bodies may experience fewer harmful algal bloom pressures compared with shallow lochs elsewhere in Scotland. However, they may face increased thermal stratification and reduced deep-water oxygen by 2040–2080.[12]

Private water supplies serving over 10,000 residents through approximately 2,560 individual systems in Highland are particularly exposed to climate-driven reductions in source reliability. These small, locally sourced systems, often reliant on springs, boreholes or small upland catchments, have limited storage resilience and are therefore more sensitive to prolonged dry periods, even if regional water abundance remains relatively high.[13]

Without continued investment in network resilience, demand management, and adaptive catchment management, these combined pressures are expected to elevate risks to people from reduced water availability and degraded water quality across the Highland region by the mid- and late-century.

 

Is the risk being managed or adapted to?

A well-developed statutory and operational framework supports the management of water availability and quality risks in Scotland. Scottish Water operates under duties set out in the Water (Scotland) Act 1980, which require the provision of wholesome water for domestic use and the maintenance of adequate supplies across its service area.[14] Scottish Water’s Climate Change Adaptation Plan (2024) and Water Resource Plans together guide investment to strengthen drought resilience, reduce leakage, and improve catchment management.[15]

Highland-specific reporting on these measures is limited, as national datasets do not disaggregate adaptation activity by local authority. However, all public supplies in the Highland Council area are managed within the same statutory, regulatory and investment framework as the rest of Scotland.[16]

Regional responsibility is most significant for private water supplies, which are far more prevalent in Highland than elsewhere. The Highland Council is required to register all private supplies, carry out sampling and analysis, provide advice to users, and complete risk assessments for regulated supplies at least every five years.[17] These duties help identify vulnerabilities, such as drought-sensitive sources, microbiological contamination, or catchments affected by heavy rainfall.

Adaptation is underway through measures such as increased network interconnection, improved monitoring of abstraction and storage, and targeted investment in priority catchments. The River Basin Management Plan for Scotland (2021–2027) sets out integrated actions across agencies to protect drinking-water sources, reduce diffuse pollution, and restore degraded rivers and lochs.[18]

However, Scottish Water’s Annual Report (2025) notes that while operational resilience and leakage reduction are improving, the pace of adaptation may not yet match the scale of climate change pressures, particularly in rural and island communities. Maintaining supply security under more extreme drought and water-quality stress will require continued collaboration with SEPA, local authorities, and communities to embed long-term, catchment-scale adaptation.[19]

 

Are there benefits from further action in the next five years, over and above what is already planned?

Further short-term action could deliver resilience and public-health benefits in the Highland region. The UK Climate Change Risk Assessment (UKCCRA3) identifies that adaptation in the water sector remains cost-effective, particularly where early investment prevents cascading failures between water, energy, and transport systems.[20] Targeted measures over the next five years could enhance both water availability and quality by accelerating leakage reduction, restoring catchments, and expanding public engagement on water efficiency.

The River Basin Management Plan for Scotland (2021–2027) and Scottish Water’s Climate Change Adaptation Plan (2024) outline substantial programmes to improve source protection and optimise supply systems. However, the Adaptation Plan notes that the projected national supply-demand deficit could quadruple by 2050, and that early interventions such as interconnecting networks, optimising storage, and managing demand will be more effective and less costly if implemented in the near term. Highland-specific supply-demand modelling is limited, but Scottish Water’s Adaptation Plan identifies Inverness and the Black Isle as areas where future deficits may emerge, indicating that early action would have direct regional benefits.[21]

Further benefits would arise from strengthening nature-based approaches within drinking-water catchments, consistent with SEPA’s integrated water management framework.[22] These include wetland restoration, buffer strips, and peatland recovery to improve raw-water quality, reduce treatment costs, and enhance biodiversity. Such approaches are particularly relevant to Highland, where many public water sources originate in upland peatland and loch catchments, and where large areas of degraded peatland have already been prioritised for restoration.[23] These measures also align with the Hydro Nation vision, which promotes Scotland’s role as a global leader in sustainable water management by linking climate adaptation, community resilience, and economic opportunity.[24]

 

Cascading and Interacting Risks 

Reduced water availability and declining quality can trigger wide-ranging cascading impacts across public health, infrastructure, and ecosystems. The UK Climate Change Risk Assessment (UKCCRA3) identifies strong interdependencies between the water, energy, and transport sectors, noting that failures in water supply or wastewater systems can disrupt energy generation and essential services.[25] In the Highland region, limited network interconnection increases this vulnerability, with smaller communities at greater risk of supply interruptions during drought or contamination events. The River Basin Management Plan for Scotland (2021–2027) highlights that deteriorating water quality affects aquatic habitats, recreation, and tourism. Flooding and sewer overflows can amplify pollution and health risks.[26] These linked pressures demonstrate how climate-related water risks can compound wider regional vulnerabilities.

 

Options for regional collaboration

• Rural supply resilience and innovation – pilot small-scale water storage, leakage detection, and remote monitoring technologies in remote and island areas most exposed to drought risk.
• Public engagement and behavioural change – Launch a regional campaign promoting efficient water use, early reporting of supply issues, and community participation in local catchment management initiatives.
• Nature-based resilience projects – Develop joint investment programmes for wetland restoration, peatland recovery, and riparian planting to improve raw-water quality, natural storage capacity, and ecosystem resilience.

References

[1] The Highland Council, “Introduction | Private Water Supplies | the Highland Council,” Highland.gov.uk, 2017, http://www.highland.gov.uk/site/scripts/documents_info.php?categoryID=1053&documentID=93.

[2] Scottish Water. Climate Change Adaptation Plan 2024. Scottish Water, 29 February 2024. https://www.scottishwater.co.uk/About-Us/News-and-Views/2024/02/290224-Climate-Change-Adaptation.

[3] Scottish Water. Climate Change Adaptation Plan 2024. Scottish Water, 29 February 2024. https://www.scottishwater.co.uk/About-Us/News-and-Views/2024/02/290224-Climate-Change-Adaptation.

[4] The Highland Council, “Introduction | Private Water Supplies | the Highland Council,” Highland.gov.uk, 2017, http://www.highland.gov.uk/site/scripts/documents_info.php?categoryID=1053&documentID=93.

[5] UK Climate Risk, “Water Sector Briefing” (UK Climate Risk, June 16, 2021), https://www.ukclimaterisk.org/publications/water-sector-briefing.

[6] Scottish Water, “2024/25 Annual Report and Accounts Performance and Prospects” (Scottish Water, 2025), https://www.scottishwater.co.uk/en/About-Us/Who-We-Are/Annual-Report.

[7] Scottish Water. Climate Change Adaptation Plan 2024. Scottish Water, 29 February 2024. https://www.scottishwater.co.uk/About-Us/News-and-Views/2024/02/290224-Climate-Change-Adaptation.

[8] Scottish Water. Climate Change Adaptation Plan 2024. Scottish Water, 29 February 2024. https://www.scottishwater.co.uk/About-Us/News-and-Views/2024/02/290224-Climate-Change-Adaptation.

[9] Scottish Water. Climate Change Adaptation Plan 2024. Scottish Water, 29 February 2024. https://www.scottishwater.co.uk/About-Us/News-and-Views/2024/02/290224-Climate-Change-Adaptation.

[10] Sniffer, “Evidence for the Third UK Climate Change Risk Assessment (CCRA3) Summary for Scotland ” (UK Climate Risk, June 16, 2021), https://www.ukclimaterisk.org/publications/summary-forscotland-ccra3-ia/#section-1-about-this-document.

[11] Scottish Environment Protection Agency, “The River Basin Management Plan for Scotland 2021 – 2027” (SEPA, December 2021), https://www.sepa.org.uk/environment/water/river-basin-management-planning/.

[12] Boca, A.-D., White, C.J., Bertram, D. (2022), A review of the risks to water resources in Scotland in response to climate change. CD2021_02. Centre of Expertise for Waters (CREW). Available online at: www.crew.ac.uk/publications. 

[13] The Highland Council, “Introduction | Private Water Supplies | the Highland Council,” Highland.gov.uk, 2017, http://www.highland.gov.uk/site/scripts/documents_info.php?categoryID=1053&documentID=93.

[14] The Scottish Government, “Water (Scotland) Act 1980, as Amended by Subsequent Legislation” (1980), https://www.gov.scot/policies/water/.

[15] Scottish Water. Climate Change Adaptation Plan 2024. Scottish Water, 29 February 2024. https://www.scottishwater.co.uk/About-Us/News-and-Views/2024/02/290224-Climate-Change-Adaptation.

[16] Scottish Environment Protection Agency, “The River Basin Management Plan for Scotland 2021 – 2027” (SEPA, December 2021), https://www.sepa.org.uk/environment/water/river-basin-management-planning/.

[17] The Highland Council, “Introduction | Private Water Supplies | the Highland Council,” Highland.gov.uk, 2017, http://www.highland.gov.uk/site/scripts/documents_info.php?categoryID=1053&documentID=93.

[18] Scottish Environment Protection Agency, “The River Basin Management Plan for Scotland 2021 – 2027” (SEPA, December 2021), https://www.sepa.org.uk/environment/water/river-basin-management-planning/.

[19] Scottish Water, “2024/25 Annual Report and Accounts Performance and Prospects” (Scottish Water, 2025), https://www.scottishwater.co.uk/en/About-Us/Who-We-Are/Annual-Report.

[20] UK Climate Risk, “Water Sector Briefing” (UK Climate Risk, June 16, 2021), https://www.ukclimaterisk.org/publications/water-sector-briefing.

[21] Scottish Water. Climate Change Adaptation Plan 2024. Scottish Water, 29 February 2024. https://www.scottishwater.co.uk/About-Us/News-and-Views/2024/02/290224-Climate-Change-Adaptation.

[22] Scottish Environment Protection Agency, “The River Basin Management Plan for Scotland 2021 – 2027” (SEPA, December 2021), https://www.sepa.org.uk/environment/water/river-basin-management-planning/.

[23] The Highland Council, “Ecology and Strategy Action Plan” (The Highland Council, November 2024), https://www.highland.gov.uk/info/1210/environment.

[24] Energy and Climate Change Directorate, The Scottish Government, “Hydro Nation: Annual Report 2022” (The Scottish Government, June 30, 2023), https://www.gov.scot/publications/scotland-hydro-nation-annual-report-2022/documents/.

[25] UK Climate Risk, “Water Sector Briefing” (UK Climate Risk, June 16, 2021), https://www.ukclimaterisk.org/publications/water-sector-briefing.

[26] Scottish Environment Protection Agency, “The River Basin Management Plan for Scotland 2021 – 2027” (SEPA, December 2021), https://www.sepa.org.uk/environment/water/river-basin-management-planning/.

Key Definitions

For the HCCROA, the terms risk and opportunity are used in specific ways. Risk refers to the potential for climate change to cause harm to people, nature, buildings, infrastructure, and communities. Opportunity refers to the potential for climate change to alter conditions in ways that could be advantageous for certain activities, sectors, or places in the Highland region, relative to current conditions. These opportunities may arise alongside significant risks and do not offset or negate them.

The assessment also highlights a second kind of opportunity: opportunities for action. The HCCROA refers to options for regional collaboration, which are distinct from opportunities arising directly from climate change. Greater benefits may be realised from coordinated action to reduce risks than from relying on limited advantages associated with changing climate conditions themselves.

 

Mental Health

Climate change is a difficult topic to engage with, and Highland Adapts appreciates that this report presents potentially upsetting information. Visit the Highland Mental Wellbeing website to learn about mental health services, information, and training available in the Highland region.

 

Project Funding and Disclaimers

Core Highland Adapts funding is provided by its partner organisations. The HCCROA was partially funded by the Scottish Government’s Climate Ready Regions Grant. The views expressed in this document are not necessarily those of the Scottish Government. Its members, servants or agents accept no liability whatsoever for any loss or damage arising from the interpretation or use of the information, or reliance upon views contained herein.

The HCCROA is a product of the Highland Adapts partnership, conducted with support from Joseph Perry Consulting, Highland Adapts partner organisations, and other regional and national contributors. The analysis, findings, and conclusions presented in the HCCROA do not necessarily reflect the views of Highland Adapts partner organisations. The HCCROA is provided for general information and should not be regarded as a substitute for professional or technical advice. Highland Adapts, Joseph Perry Consulting, the report authors, and report contributors accept no responsibility for any loss or damage arising from the use or interpretation of information contained within the HCCROA.

This page was last updated on 3 Mar, 2026.