Scotland’s freshwaters

Fresh waters represent about 2% of the area of Scotland, but Scotland’s resources make up more than 90% of the total volume of fresh water in the UK. The great diversity of Scottish fresh waters makes an important contribution to the character of the landscape and provides a range of wildlife habitats.

Rivers and burns in Scotland range from small trickles and springs at the head of catchments to the mouth of the River Tay at Perth, which has the largest average annual river flow in Britain, with nearly 200,000 litres flowing past every second.

Scotland also contains more than 30,000 freshwater lochs, ponds and lochans, ranging from tiny lochs cradled in mountain corries to the large deep-water lochs of many Highland glens.

Scotland also has important freshwater wetlands. About 40% of all active raised bog in the UK is found in Scotland, principally in the lowland areas of the Central Belt. Lowland rich fen is also present on waterlogged floodplains alongside rivers and streams.

These natural freshwaters are accompanied by a variety of ‘artificial’ waters including reservoirs, canals and manmade ponds.

All these different freshwaters provide a wide range of benefits to society as well as supporting important and varied wildlife. Some of the benefits we receive from the fresh waters of Scotland include:

• water supply for numerous domestic, industrial and agricultural purposes;
• waste disposal;
• raw materials for the food and drink industries (e.g. whisky distilling);
• energy for hydropower generation;
• fishing;
• a source of inspiration for the arts;
• extremely important resources for education, quiet enjoyment, organised recreation and tourism.

Rivers and burns

Scotland’s rivers and burns are home to a great variety of species, some world famous and others much less well known and understood. Most famous of all is probably the Atlantic salmon, or ‘king of fish’. Not only does it have a long relationship with humans and is an extremely important contributor to rural economies, but it also plays an important part in the overall ecology of our rivers. Less well known are species such as lampreys or freshwater pearl mussels. Lampreys must be amongst the most rarely seen and poorly understood of all the fish species found in Scottish rivers. Their fossil remains show that they were around long before the dinosaurs and many familiar plant groups. The freshwater pearl mussel are also rarely seen these days as they have suffered a dramatic decline in numbers due to past fishing for their pearls. Pearl fishing is now illegal and with increased protection it is hoped the species will begin to recover.

Rivers also play an important role in the Scottish landscape with dramatic waterfalls in many uplands, meandering channels in the lowlands, and they provide important ‘green corridors’ through many cities and towns (see August).

Scotland has a huge number of freshwater lochs and lochans. They come in all shapes and sizes and this year it is 100 years since the first large-scale survey of the depths of Scottish lochs was completed. This survey included 562 Scottish lochs and the results can now be accessed via the National Library of Scotland. The survey found that the deepest loch in Scotland is Loch Morar at 1,017 feet – it’s worth remembering that the sea around Scotland doesn’t get that deep until the dip of the continental shelf beyond St Kilda!

Scotland’s lochs support important species and habitats. For example, Arctic charr are found in many of our deep and cool lochs. This rarely seen fish species was one of the first species to colonise Scotland’s lochs after the last ice age and has been isolated in many of these lochs ever since, resulting in a diversity of forms and populations. Increasingly rare plant species such as Shetland pondweed and slender naiad are also found in lochs which are largely free from pollution and have clear water.

Smaller ponds and lochans can also support important species, such as great crested newts. Ponds can be one of the best ways of increasing the importance of a garden for wildlife, offering a home to newts, dragonfly larvae and mayflies amongst others.

Managing fresh waters

The way that Scotland’s water environment (including the fresh water) is managed is changing. The introduction of the EC Water Framework Directive means that a process of managing water by river basins has recently started, led by SEPA. It is hoped that this system, based on river catchments and taking account of a wide range of pressures, will result in significant improvements to the status of waters across Scotland.

Other useful links and information :

• Conservation of Atlantic Salmon in Scotland
• Information about important species and habitats in rivers
• River Restoration Centre
• Guidance on the management of ponds, pools and lochans
• Guidance on watercourses in communities
• Guidance on managing river habitats for fisheries