Despite recent heavy rain, long-term water scarcity pressures remain after one of the driest starts to the year for decades.
The latest water scarcity report from the Scottish Environment Protection Agency (SEPA) shows widespread improvement across the west of the country. In contrast, some catchments in the north and North East are continuing to deteriorate, while others have not seen enough rain to recover.
This week, Wick and Helmsdale river catchments have been raised to moderate water scarcity. If locally dry conditions continue, areas including the Avon catchment (Spey), the lower Dee and the Water of Feugh, and Helmsdale may reach Significant Scarcity next week – meaning restrictions on businesses taking water from the environment will be needed.
Rain over the past week has led to recovery in areas of the West Coast, Highlands and Islands. But the east has remained largely dry, due in part to the rain shadow effect where moist air loses much of its rain as it moves over mountains, leaving drier conditions on the other side.
This spring has been the second driest in 100 years in eastern Scotland and some areas have had below average rainfall for more than 12 months. While rain is forecast in the coming week, SEPA hydrologists say well above-average rainfall will be needed to reverse the effects of the long dry spell.
This week’s update
- Wick and Helmsdale river catchments have been raised to Moderate Scarcity.
- The Tay and Esk (Dumfriesshire) have recovered from Moderate Scarcity to Alert.
- The Conon, Beauly, Ness, Forth, Annan, Nith, Dee (Galloway), Cree, Doon, Clyde, Irvine and Ayr catchments have all recovered from Alert to Early warning.
- Firth of Clyde, Northwest Highlands and Kintyre have recovered from Alert to Early warning
- Leven (Dunbartonshire), Argyll Coast, Loch Linnhe, Loch Alsh and the Inner Hebrides all recovering from Early warning to Normal.
Measured data
SEPA’s Drought Risk Assessment Tool (DRAT) uses measured river flow data from gauging stations across the country, to monitor current environmental conditions. This data is combined with information from rainfall gauges, Met Office forecasts, soil moisture data, and fieldwork by SEPA staff to produce the national water scarcity picture.
If river flows at a DRAT station fall below a critical level (called Q95) for 30 days or more, the associated area is classed as at significant water scarcity. The tool is available to view online on SEPA’s website.
Claire Tunaley, Senior Hydrologist – Water Resources Unit, SEPA said: “By monitoring current river flows at key points across the country, and using rainfall data, soil moisture data, groundwater levels and what we see in the field, we can assess where recovery is happening and where risk remains.
“Our Drought Risk Assessment Tool, known as DRAT, uses data from river gauging stations to monitor flows closely. If flows at these stations fall below the Q95 threshold for 30 consecutive days, it indicates significant water scarcity and a high risk of ecological impact. Q95 means the flow is lower than it would be on 95% of days in a typical year – in other words, extremely low.
“When rivers reach critical lows, it affects the whole ecosystem – including fish, plants and the wider natural balance. Protecting these ecosystems now helps maintain the long-term health of our rivers.”
Regulatory restrictions
Eilidh Johnston, SEPA’s Senior Manager in Water Industry and Rural Economy, said: “SEPA has a clear duty to protect Scotland’s rivers and water environment, not just today but for the future. When conditions reach the point where any further reduction in flow would risk damage to the environment, we must act.
“We know that water is vital for people, farms and businesses, which is why we’ve been working so closely with abstractors and membership bodies to provide information about how the water scarcity situation has been developing in recent weeks. But when river levels fall too low for too long, we must act to prevent long-term harm to the environment and future supplies.
Any regulatory action we take is based on robust evidence-based assessments, using up-to-date scientific data and hydrological analysis. That includes measured river levels, rainfall records, soil moisture and weather forecasts – as well as insights from our field staff.
“If restrictions are necessary, they will be targeted, time-limited and lifted as soon as the conditions allow. We want to support Scotland’s water resilience, and we make our decisions based on science and hard facts. That’s what powers Scotland’s National Water Scarcity Plan and our weekly assessments. This is a coordinated, evidence-driven response to serious environmental pressure.”
