Lochs of Scotland - Largest and Deepest Lochs

Largest and Deepest Lochs

This table includes the twelve largest lochs by volume, area and length as listed by Murray and Pullar (1910). The volume of water in Loch Ness is nearly double that in all the lakes of England and Wales combined. Murray and Pullar also note that the mean depth of Loch Ness is 57.4% of the maximum depth - higher than in any other large deep loch, with Loch Avich coming closest at 52.4%. Lochs Maree, Shiel and Ness are recorded as being the narrowest of the large lochs in relation to their length.

Neither the Loch of Stenness nor the Loch of Harray on Mainland Orkney are large enough to appear in the above table (Loch of Harray is 16th by area) but at higher stages of the tide they are connected to one another and to the marine waters of Hoy Sound. The former is the largest brackish lagoon in the UK and the latter, whilst predominantly freshwater, does have a transition zone in the vicinity of the Bridge of Brodgar where the two are connected. The two lochs together cover an area of 19.3 km² but have a volume of only 0.047 km³ due to their shallow nature. Loch of Stenness has a maximum depth of 5.2 metres (17 ft). Although flow between the two lochs and the sea can be observed, the water levels only experience small changes with the movements of the tide.