How can famously wet Scotland be on water scarcity alert?

The rains may have come but the drought is not over. The SEPA report said: "The isolated thunderstorms in the north earlier in the week have done little to alleviate the overall water scarcity situation."

How can Scotland, a country long considered to have rain aplenty, be putting out water scarcity alerts for the second year running?

When it comes to drought it’s not just what rain falls now that matters, but what happened earlier in the year. It's not just about the last couple of weeks of June, but about the rain in spring and the Highland region of Scotland saw its eighth driest May since 1890. Rainfall totals for spring were also below average for northwest Scotland.

According to the Met Office, this has been the driest spring in northern Scotland, since 2018, and a season in which Inverness and Sutherland recorded just under two-thirds of their expected rainfall. Meanwhile, across the UK only 55% of expected rainfall was recorded in May, making it one of the driest Mays in recent times, the Met Office said.

Which bodies of water are drying up?

Among the sites that have been particularly impacted by the drought have been Loch Maree, which is at the highest level of concern, Loch Ness, the River Ness, and the Esk area of Dumfriesshire, all of which are at "moderate" water scarcity.

Joining those areas of "moderate" scarcity this week, however, are the Inner Hebrides, , the whole of the southwest, along with the Clyde, Leven, Awe and Etive, and Tay areas, all of which have increased their level of concern.

Loch Maree

Last month Loch Ness was at its lowest levels since reporting began in 1990 - and not much has improved.

This week, Brian Shaw, river director of the Ness District Salmon Fishery Board, said there was “slightly better news”. “Heavy, thundery, afternoon showers over the last few days raised the level of Loch Ness, by an inch or two, as it did the River Ness. However, that was short-lived, it is now hotter than before and, if this dry weather continues, we will soon be at rock bottom levels again.”

The recent hot weather, said the report, has led to rapid drying of ground conditions.

The hot weather is expected to persist in the coming week with showers developing on Saturday and Sunday.

However, the SEPA report said: "The anticipated average rainfall over the coming days is expected to do little to alleviate the current water scarcity situation and dry weather is expected to dominate into late June and early July."

It noted: "If there is no recovery in river levels there will be several areas seeing significant water scarcity in the coming weeks, starting with the Esk area of Dumfriesshire next week. If rivers remain at very low flows for more than 30 consecutive days there is a heightened risk of severe, long-lasting ecological impact."

READ MORE SEPA warns Scotland to 'brace itself' for water scarcity

What does this mean for the future?

Scientists have been predicting for some years now that Scotland is likely to experience more drought and water scarcity as a result of climate change. Scotland, famous for its dreich weather, even has a national water scarcity plan.

For instance, UK climate change projections predict a reduction in summer river and waterway flows particularly in East Scotland. They indicate a likely increasing frequency, magnitude, and duration of droughts. Met Office probabilistic climate change projections suggest that summers in Scotland are likely to become hotter and drier – although there are also likely to be periods of more intense rainfall throughout the year.

In 2022 Scotland’s Centre of Expertise for Waters (CREW) published a review of the risks to water resources in Scotland in response to climate change, which described a “consensus relating to an increase across all metrics (frequency, magnitude and duration) Scotland-wide in a warming climate.”

“In terms of droughts,” it said, “in Scotland, compound hydro-hotspots (droughts and floods) are projected to occur across eastern Scotland and the Highlands and Islands, including the Loch Ness and River Tay catchments in the far future. In the 2050s, irrigation demand, especially in summer, may rise due to an increase in temperatures alongside an increase in potential evapotranspiration.

The review also noted that the global climate is "changing due to human activities". "Even in ‘water rich’ countries like Scotland, these changes will have implications for the future of water resources.”

Are we already seeing the impact of climate change on water scarcity?

Not yet. Jamie Hannaford, a hydrologist at the UK Centre for Ecology & Hydrology said, "Future climate change projections certainly indicate an impact of warming climate on UK river flows, including in Scotland – with decreasing summer flows and more severe droughts. Overall, river flows will increase across much of Scotland, driven mainly by increases in winter flows and high river flows and there will be more floods as well as droughts."

"However, while we have observed strong increases in winter flows in Scotland, especially in the west, there is limited evidence for any strong observable impact of climate change on drought trends. This doesn’t mean climate change is not having an effect, just that at the moment it is not apparent above the ‘noise’ of year-to-year variations."

Who is likely to be impacted more?

In a 2020 study CREW showed that North-East Scotland, which typically has drier weather than the rest of the country, was likely to experience more dryness in the future. It noted that this was likely to “particularly impact those businesses and households that rely on private water supplies  - of which the North-East has the highest density”.

READ MORE: Heatwave in Scotland sees water usage soar as warning issued

What is happening in Scotland’s rivers?

The UK Centre for Ecology and Hydrology recently published its review of May and outlook report for June. It contrasted “above normal” river flows across southern England, with “below normal (and notably or exceptionally low in many catchments)” flows in Scotland. “The outlook for June,” it said, “is for below normal flows across the north and west, with notably or exceptionally low flows likely to persist in some catchments, particularly in western Scotland.”

Groundwater levels, it said, were also below normal in Scotland in May and likely to continue so through June.

What other droughts have there been recently?

2022 has not been the only recent drought. The drought of 2018 had a significant impact on rural water supplies. Private water supplies across the country ran dry and at least 500 of them requested emergency assistance from local authorities. Yet, in spite of this, many in Scotland did not seem to be aware of the issue. A survey conducted in 2021 found that 37% of respondents felt that drought was unlikely to ever be a problem for Scotland.

What will this mean for farming and food security?

A key issue is how much water is taken from our lochs, rivers and other waters - known as “water abstraction” - which is often what farmers turn to when the land is dry and their crops need irrigation.

In a summer heatwave in Scotland that saw temperatures peak at 30C, parts of Fife were issued a red water shortage warning and SEPA suspended water abstraction from the river Eden, which had reached “critical” levels, impacting farmers in the area.

At the time, NFU Scotland the ban represented a “devastating blow” to vegetable growers. The union said the economic impacts of the decision would be "felt for weeks and months to come", adding that "many crops will fail, jobs will be lost, and the viability of some farms will be at risk.

In a drier Scotland there is likely to be a rising demand for irrigation. According to a blog by ClimateXChange, research shows that as drought conditions worsen, agricultural land is likely to become less productive when soils are dry. “This means that Scottish potatoes and other vegetables will require significantly more irrigation water during the summer.”

Irrigation in Coupar Angus, Perthshire (Pic: Ron Stephen)

But it is unlikely that it will be possible for abstraction to meet this demand without negative environmental impacts on waterways. Therefore new strategies may be needed from using different crop types to more efficient management practices and increased use of on-farm water storage.

For instance, Scottish farmers this year were urged, by SEPA, to build lagoons on their land and put plans in place to deal with possible water shortages this summer.

Research into the implications is ongoing. Among those scientists currently modelling the impacts is Dr Miriam Glendell of the James Hutton Institute.

She said: “In our current research funded by the Scottish Government we are developing drought risk and vulnerability models to explore risks to agricultural water demand and vulnerability to drought in different sectors, for example, whisky production and private water supplies. We are also modelling the impacts on groundwater resources and nitrate pollution in Scotland under future climate change scenarios.”

How are our water stores right now?

Scotland’s public water supply is abstracted from 422 different water sources across the country, from, says the publicly-owned company’s website, “very large reservoirs to very small river intakes”.

Levels of water in Scotland’s reservoirs and water sources, are, according to Scottish Water’s website, currently, at 77 percent, a tenth lower than average.

How much water do we use – and could we use less?

Water usage per person in Scotland is the highest in the United Kingdom on average, at 165 liters -  more than in England, Wales, and Northern Ireland, where less than 150 liters is used per person per day on average.

Projections from the World Resources Institute for 2040 show that in the UK water stress will be “medium to high”. This compares to Germany and Ireland which are projected to be “low to medium” and Spain which is projected to be “extremely high”.

Scottish Water has a list of tips for saving water, which includes cutting two minutes off your shower, flushing the toilet less, installing a water butt for your garden, turning the tap off when brushing teeth and fixing dripping taps.