Kilbirnie Loch (NS 330 543), is a freshwater Loch situated in the floodplain between Kilbirnie, Glengarnock and Beith, North Ayrshire, Scotland. It runs south-west to north-east for almost , is about wide for the most part and has an area of roughly 3 km2 (761 acres). It has a general depth of around 5.2 metres (17 feet) to a maximum of around 11 metres (36 feet). The loch is fed mainly by the Maich Water, which rises in the Kilbirnie Hills near Misty Law (507m or 1663 feet), and is drained by the Dubbs Water that runs past the Barr Loch into Castle Semple Loch, followed by the Black Cart, the White Cart at Renfrew and finally the River Clyde. The boundary between East Renfrewshire and North Ayrshire, in the vicinity of the loch, runs down the course of the Maich Water along the northern loch shore to then run up beside the Dubbs Water. History Origins and placenames Hector Boece (1465–1536) is the first to publish a reference to the loch, using the name 'Garnoth', in his book of 1527 the 'Historia Gentis Scotorum' (History of the Scottish People), saying that nocht unlike the Loch Doune full of fische. There is a long history of drainage schemes and farming operations in the area, with co-ordinated attempts dating from about 1691 by Lord Sempill, followed by Colonel McDowal of Castle Sempil in 1774, James Adams of Burnfoot, and by others. Until these drainage works the two lochs nearly met and often did during flooding, to the extent that early writers such as Boece, Hollings and Petruccio Ubaldini regarded the lochs as one, using the name 'Garnoth' or 'Garnott'. The Castle Semple and Barr Lochs lie in an area previously covered until more recently by one large loch known as 'Loch Winnoch', however by the end of the 18th century silt from the River Calder had divided the loch into two. In 1814 Barr Loch and the Aird Meadow was bunded and drained, however after WW2 the area was gradually abandoned for agriculture. 'Loc Tancu' is seemingly the earliest recorded name from circa 1210 and the name 'Loch Tankard', 'Thankard' or 'Thankart' was used locally. A farm named 'Unthank' or 'Onthank' existed until the 19th century near to the old Nether Mill opposite the lost 'Cairn' island and together with 'Thankard' may be derived from 'Tancu'. The term 'Garnoth' has also