The hydrogeology of the Gort Lowlands

Abstract

The Gort Lowlands is an extensively karstified lowland limestone catchment located in Co. Galway, on the western coast of Ireland. The hydrogeomorphological history of the Gort Lowlands is complex; recurrent karstification and glaciation of the Carboniferous limestone formations has created an extensive conduit and cave system that dominates groundwater flow. Variations in the lithology, stratigraphy, fracturing and faulting of the limestone bedrock have all played a role in shaping this subterranean system. So too has the nature of catchment recharge, with just over half of annual recharge supplied by rivers from the adjacent non-carbonate Slieve Aughty Mountains. Surface flow in the lowlands is intermittent and drainage is via the karst network which discharges at a series of intertidal and submarine springs in Kinvara Bay. The catchment is also interspersed with seasonal lakes known as turloughs, which provide storage for excess recharge that cannot be accommodated by the groundwater system. The complex regional hydrogeology poses significant water resource and land management challenges. This paper contributes towards addressing these challenges by presenting the accumulated hydrogeological knowledge, including the genesis, behaviour and principal features of the catchment.