Crotty Dam Dewatering Outlet Shaft
The Xypex waterproofing system was specified by the Hydro Electricity Commission of Tasmania for use in this deep concrete shaft which comprises part of the King River Power Development Scheme. The shaft is approximately 76 metres (250 ft) deep and is adjacent to the Crotty Dam which is located near Queenstown on the West Coast of Tasmania. Internal surface preparation for the Xypex crystalline treatment included the use of Xypex products for repair of structural defects, patching of tie rod holes, and sealing of high pressure leaks. Prior to these repairs, it was estimated that the shaft was taking in over 400 litres (106 US gallons) of water per minute. Once the repairs were completed, a two coat application of Xypex Concentrate was applied to internal shaft surfaces totalling 1,600 m2 (17,200 sq ft). Because of the success of this difficult application, the Hydro Electricity Commission has specified the Xypex system on another larger concrete shaft located at the Anthony Power Station.