Water scarcity in Scotland: really?

Dr Sarah Halliday and Dr Richard Gosling, University of Dundee 

Scotland has a global reputation as a ‘wet’, water-rich nation. Often when we think of Scotland, it evokes images of our beautiful lochs and rivers, and notions of an abundance of water. It can therefore be challenging to understand that Scotland is vulnerable to periods of water scarcity. However, across Scotland water scarcity is a real and increasing risk. 

Each year since 2018, the Scottish Environment Protection Agency (SEPA) has declared moderate to significant water scarcity in a number of different regions, including both the west and east coasts. These events have resulted in significant impacts for our freshwater ecosystems and our water-dependant industries. In July 2021, some distilleries in the highlands had to cease production due to insufficient water. In August 2022, SEPA restricted water abstractions for the first time in the Tweed and Eden catchments, directly impacting agricultural crop irrigation. There have also been reports of toxic blue-green algal blooms in some lochs and reservoirs as water levels have fallen to historic lows, and mass fish kills due to high water temperatures and reduced flows. 

What causes scarcity? 

Water scarcity occurs when access to water, of sufficient quality, to meet both human and ecological needs becomes limited. It is controlled not only by the supply of water from rainfall but also by the demand for water within a region. 

Our changing supply 

Across Scotland, rainfall rates are highly variable. The water supply can vary across Scotland by over 3,000mm annually, with some areas wetter than the Amazon rainforest whilst others are drier than East Anglia. In addition, much of our annual rainfall can be delivered in short-duration, high-intensity events, leaving long spells with little to no rainfall. The capacity to capture and store water during times of excess supply also varies from region to region and can be limited particularly within our island communities. 

Recent data indicate that Scotland has experienced an increase in meteorological droughts, particularly in the spring and summer. This trend has been linked to broader climate changes, such as higher temperatures, which increase evapotranspiration, exacerbating dry conditions. Future projections suggest that these patterns will intensify, with hotter, drier summers becoming more common by the mid-21st century, leading to more frequent and severe droughts. 

Our changing demand 

The demand for water in Scotland spans sectors including domestic, agricultural, and industrial uses. Our natural ecosystems also have water requirements to maintain biodiversity and ecological health. Reduced water flows and levels can lead to habitat loss, reduced biodiversity, and decreased water quality, due to higher temperatures and increased pollution loads. 

Most domestic properties receive their water from Scottish Water, but a small percentage of properties access their water from a private supply, such as a spring or shallow borehole (3.6%). These can be highly vulnerable to extended periods of dry weather. In the 2018 heatwave, 500 failures of private water supply required bottled water provision as an emergency supply. Although overall water abstraction for public use has decreased in recent years due to improved efficiency and reduced leakage, the amount of water being used in domestic settings is increasing. Since Covid, average domestic demand has risen to 180 litres per person per day (lpd), significantly higher than other European countries (eg, Germany = 125lpd). However, many households significantly underestimate their water use. 

Many of our key industries are also dependent on high-quality, reliable water supply. For example, since 2010, there has been a major expansion of the distillery sector in Scotland, with 22 of Scotland’s 32 local authorities now having a distilling business presence. Water management can be a challenge in the small catchments many distilleries rely on, where there are limited alternative sources and where supplies can be servicing other uses such as rural homes, tourist sites, crop irrigation and hydropower generation. 

Managing water scarcity 

Addressing water scarcity in Scotland requires a multifaceted approach that considers both supply and demand. This includes improving water use efficiency, enhancing drought resilience, and safeguarding natural ecosystems. 

While there is much to be done at the government and corporate levels to improve water use efficiency, there is also much that can be done at the individual level to promote improved water stewardship. Our water resources are precious, and we need to treat them as such. Thinking about how we each personally use water in our home and work, and the positive changes we can make to reduce this, is a great way to address how we can help our water resources become more resilient to the changes ahead.