Scotland’s freshwater

Key messages

• Scotland has more than 125,000 km of rivers and streams varying from small highland burns to deep, wide lowland rivers such as the Tay. That’s enough to go round the Earth three times.
• There are over 30,000 freshwater lochs in Scotland, with the Western Isles and Sutherland having the highest concentration of lochs. The eight largest lochs cover an area of 301 km² – almost five times the area of the 17,637 smallest lochs combined.
• Many of the smallest lochs and lochans are on peatlands in the northern and western Highlands. Larger lochs are often found in U-shaped valleys that were formed during the last ice age. Loch Lomond has the largest surface area (71 km²), while Loch Morar is the deepest at 310 m. Loch Ness holds the most water with 7,452 million m³, which is more than all the English and Welsh lakes combined.
• Scotland also has a 220 km canal network. 
• Scotland’s groundwater is a valuable resource used to supply drinking water, agriculture and industry. Groundwater also feeds wetlands and river flows during dry spells and is vital to the maintenance of their rich ecology and biodiversity.
• Scotland’s surface waters and groundwaters are monitored regularly to assess their condition. The information is gathered every year and presented as the annual classification.
• Every six years Scotland produces a river basin management plan. This describes the condition of the surface waters and groundwaters, the pressures affecting them, and the actions planned to alleviate the pressures. The most recent river basin management plan was published in December 2021

The main pressures currently affecting the condition of rivers and lochs in Scotland are:

• Man-made barriers to fish migration
• physical changes to the beds and banks
• rural diffuse pollution.

Groundwater quality is affected by:

• Diffuse pollution from rural sources
• discharges from industries such as mining and quarrying.

Groundwater flows and levels are affected by:

• Agricultural irrigation
• industry.

Data

Scotland’s surface waters and groundwaters are monitored regularly to assess their condition. The information is gathered every year and presented as the annual classification.

Every six years Scotland produces a river basin management plan. This describes the condition of the surface waters and groundwaters, the pressures affecting them, and the actions planned to alleviate the pressures. The most recent river basin management plan was published in December 2021. The third plan was published in 2021 and sets ambitious targets for Scotland’s water environment. It also describes the condition of the water environment in 2020 and explains the main pressures affecting it. The water environment hub allows you to explore the data and view maps. You can view how the overall condition, physical condition, water flows and levels, and water quality are expected to change over time for surface freshwaters and groundwaters. 

Water resources refers to the flows and levels of water and indicates how much water is being used and how much is available to serve all its vital functions. The flows and levels in Scotland’s water environment are currently at good or better condition in 90% of rivers, lochs and groundwaters. This is up from 88% when we published the second RBMPs.

Fish migration. Structures such as weirs, culverts and bridges can block migratory routes for fish and deny them access to good quality habitat for spawning and rearing. 88% of Scotland’s rivers and lochs are at good or better condition for fish migration. This is up from 86% when we published the second RBMPs.

Physical condition of the water environment refers to the extent and impacts of modifications and structures, such as embankments; culverts; and the widening and straightening of rivers. All these activities can affect the benefits Scotland derives from the water environment, such as reduced flood risks; enhanced landscape quality; improved habitats for animals and plants; and health/wellbeing and recreation for people. The physical condition of Scotland’s water environment is now at good or better condition in 90% of our waters.

Classification - In the interactive data analysis application, you can view the current status and pressures of surface freshwaters and ground waters.

What are we doing?

The water environment provides many services and benefits that are either essential to us or that enrich our lives. It is important that we keep our freshwaters in a healthy condition so that they can continue to perform these vital functions.

River basin management planning is about protecting and improving Scotland’s water environment in a way that balances costs and benefits to the environment, society and economy The third river basin management plan describes the state of Scotland’s water environment in 2020.

SEPA is working in partnership with other public bodies, industry and land managers to help protect and improve the water environment.

You can find out more about the actions to create Healthier and more resilient communities, improve Scotland’s water supply and wastewater system, promote sustainable and resilient rural land use and remove artificial barriers to fish migration.

Water levels on lochs and rivers around Scotland are monitored, producing valuable information used by businesses, households and leisure users. SEPA monitors water levels at 392 sites throughout Scotland. Most of the stations are situated on rivers, but data is also collected from several tide and loch level recorders.

• Why are water levels monitored?
• How is the information gathered?
• How is the information interpreted?

The Water Environment Fund funds projects that aim to help restore Scotland’s catchments from the source, through rivers, lochs and floodplains, into estuaries and out to sea.

Policy and legislation

Water Environment (Controlled Activities) (Scotland) Regulations 2011 –known as the Controlled Activity Regulations (CAR) – and their further amendments apply regulatory controls over activities that may affect Scotland’s water environment. These include discharges of wastewater or industrial effluent, and abstractions for irrigation, hydropower or drinking water, as well as engineering activities in or near rivers.

This legislation arose from the European Water Framework Directive, which became law in Scotland as the Water Environment and Water Services (Scotland) Act 2003 (WEWS Act)

The regulations cover rivers, lochs, transitional waters (estuaries), coastal waters, groundwater, and groundwater dependant wetlands. You can find more detailed information in SEPA’s Introduction to regulations and CAR practical guide.

Water Environment and Water Services (Scotland) Act 2003 makes SEPA responsible for coordinating the development of Scotland’s RBMPs.

Flood Risk Management Act 2009 provides opportunities to restore and enhance river habitats as part of a more sustainable approach to flood management.

SEPA has more information about water regulations in Scotland.

NetRegs provides a list of Water Legislation that may affect businesses in Scotland.

Scotland’s third Land Use Strategy sets out the vision, objectives and policies to achieve sustainable land use. Making the most of communities' natural assets: green infrastructure explains how communities and those who serve them can use water in a way that works with nature. These principles are embedded in River Basin Management Plan practice and will be given increased prominence in future RBMP delivery programmes.

Groundwater can be adversely affected by a range of activities and there is specific legislation and guidance covering each activity. SEPA’s website provides information on how proposed activities may have affect groundwater and how to comply with regulations aimed at managing and protecting it.