Why Scotland, one of Europe's wettest countries, needs to get ready for severe drought

A drought that relatively recently would only have happened about once every 20 years in Scotland can now be expected every three years on average

The rain has come, but is Scotland ready for a future with more drought? Rainfall last Friday signalled the end to an unusually dry and sunny period of weather for many people in Scotland, just in time for the bank holiday weekend.

A weather front sweeping across the country brought much needed rainfall to the east, including the first for Leuchars in Fife since April 18. Scotland as a whole has seen roughly 40 per cent of its usual rainfall from the start of March. This has left reservoirs down to 81 per cent of their capacity, raising concerns that low summer rainfall could lead to issues with water availability.

This follows an unusually dry autumn and winter for central and southern Scotland, according to Met Office data. Meanwhile, the dry conditions in spring have contributed to a record wildfire season with major fires in the Forest of Galloway and Islands of Arran, Bute and Skye.

Scotland might be famous for rain, like this downpour in Helensburgh in January, but drought is becoming a real problem, particularly for the east coast (Picture: Jeff J Mitchell) | Getty Images

Scots use more water

Concerns about a lack of water in one of Europe’s wettest countries may seem overblown. However, it is important to remember that the heaviest rain falls in the sparsely populated west, whereas there is substantial water demand in the relatively drier and more populated east for public and industrial use.

Moreover, such perceptions of a limitless resource may contribute to high water usage. The average Scot uses 180 litres of water a day, considerably more than the 140 litres used by people in England and Wales. It is also possible that the fixed rate most Scottish people pay for their water, rather than metered billing, plays a role. Demands from agriculture and the whisky industry are other key contributors to water use.

Whilst the rain has arrived, we aren’t out of the woods yet. Most areas across the east of Scotland show moderate water scarcity, according to the Scottish Environment Protection Agency (Sepa), and very heavy rainfall would be needed to replenish water levels.

High demand, low supply

Regardless of what the summer brings, this spring may be a harbinger of future drought. Climate change simulations project drier summers in future due to increased evaporative demand from a warmer atmosphere. A NatureScot report found that what was previously a one-in-20-year drought event, based on the period between 1981 and 2000, will occur every three years on average between 2021 and 2040.

Areas with a low water supply yet high demand, such as Edinburgh, Lothian, Dundee and Fife are likely to become increasingly exposed to drought. Additionally, water demand is expected to increase in the east of Scotland due to population growth and a demographic shift of people from west to east.

Compounding this, water demand rises during a drought – for example, as farmers increase the amount of irrigation – suggesting that Scotland will become increasingly vulnerable to extended dry periods. Consequently, it is clear that steps are needed to increase our water system’s resilience to drought.

On the demand side, this could include information campaigns to help the public to understand that water is a finite resource and how to use it more efficiently. The largest contributors to domestic water use are toilet flushing and taking a shower or bath. Each minute in the shower uses about ten litres, while a leaky toilet can waste up to 400 litres a day. Additionally, using eco-mode on a washing machine can save around 15 litres.

Encouragingly, a short-term appeal from Scottish Water to lower water use may have helped in reducing demand by 60 million litres a day last week.

Greater drought resilience needed

Research by Consumer Scotland recommended that the Scottish Government should update building standards and improve access to information regarding water-efficient appliances. At present, consumers wishing to pay based on what water they use have to spend hundreds of pounds to cover the cost of surveys and the installation of meters.

Perhaps making it easier to switch to a metered connection could conserve water and help consumers save money in the long run? Nevertheless, demand-side reductions can only go so far. A 2023 report by the Climate Change Committee, the UK’s independent assessor of progress on climate change, noted a lack of drought resilience standards and water-leakage reduction targets in Scotland.

The report also criticised the limited awareness and management of interdependencies across infrastructure sectors. Since then, Scottish Water released its Climate Change Adaptation plan which found that investment of £2 billion to £5 billion would be needed by 2050 to maintain the current levels of service. The plan includes measures to reduce the number of customers fed from a single water source, prevent leakage and lower consumption. Scottish Water also aims to build drought response into its operations and water-system plans.

A Scottish Government consultation about the future of the water industry has indicated that there is support for revisiting current water policy. It is important that the government acts on the results of this consultation to ensure a more effective and adaptable water system.

We need to realise that water, particularly clean drinking water, is a precious resource. This spring has taught us that it is not always abundant, even in Scotland. There are signs of progress in identifying the challenges that climate change and demographic shifts will bring to our water system.

However, much more work is needed to ensure a drought-resilient future for Scotland.

Dr Matt Patterson is a research fellow in climate science and machine learning at the National Centre for Atmospheric Science at the University of St Andrews