In winter and other times of heavy rain all the fissures in limestone fill with water. If this happens, temporary lakes called turloughs form. These are common in the lowland regions of Galway. In summer they dry up as the water sinks underground. Turloughs are often
called seasonal or
disappearing lakes, e.g. Gort, County Galway. Filling of the turloughs contributed to the devastating floods in County Galway in the winter of 2009 - 2010.
Summer Dry lake bed
Limestone Water table: rock below this is full of water
Winter Turlough
Water table rises creating a winter lake or turlough
Fig. 11 Exam Diagram: A turlough in summer and winter
OCK TYPES AND LANDSCAPES
Fig. 12 Carron Turlough, County Clare
Underground limestone landforms Caves/caverns
Once underground, the water from all the swallow holes and fissures combine to create streams. By the process of erosion these streams enlarge the passages through which they flow to make caves and caverns. Eventually the underground streams reappear at the surface as springs or resurgences. Caves can be seen at Dunmore, County Kilkenny and Marble Arch, County Fermanagh. Large caves are called caverns.