Theresa Creek Dam, constructed in 1982 and located about 18 km south of Clermont town is the only drinking water source for the town of Clermont. The 2021 comprehensive inspection report by consulting engineers on Theresa Creek Dam infrastructure has identified several critical issues that demand immediate attention for ensuring the dam’s structural integrity and operational safety. A concerning finding is the variable gap between the left retaining wall and the staircase, which is assumed to be widening over time. Seepage was notably observed through the dam’s horizontal and vertical drains, particularly around the left concrete terraced section (55 m) and the right concrete terrace section (150 m). This phenomenon, coupled with the detection of cracks in the concern apron slabs, highlights areas of concerns.
In accordance with the Queensland Dam Safety Guidelines (2003), a comprehensive dam safety plan for Theresa Creek Dam was developed which includes regular monitoring and data collection, to maintain safety standard. This includes twice a week dam inspection, seepage data collection and monthly measurement of cracks identified in the dam apron and variable gap between the retaining wall and staircase. Similarly downstream erosion data is also collected after major flood incident in the area. In this paper data collected in past one year is presented which showcase the inspection, monitoring, and investigation aspects of the Thresa Creek Dam “Dam Management System” to meet regulatory compliance requirement and to ensure dam safety.
Author
- Tahir Khan, Technical Officer Dams, Isaac Regional Council, Qld
- Stephen Wagener, Manager Operation & Maintenance, Water and Wastewater, Isaac Regional Council, Qld