2023 – Leaky by Name, Leaky by Nature: A Novel Approach to Leakage Reduction at Lake Leake Dam

Rhys Koppelmann, Josh Clark, Chris Topham

Lake Leake Dam is a 140 year old water supply dam located 570m above sea level at the headquarters to the Elizabeth River on the East Coast of Tasmania. In 2015 the dam suffered a piping incident and required emergency repairs to staunch the leak and avert failure. Subsequent analysis has demonstrated that, despite its history, piping failure is not a governing risk, and surprisingly, allocation of scarce funding was more effectively allocated to addressing other failure modes to extend the life of the dam. In particular, there were a number of seepage paths through the stone masonry wingwall, and outlet works wall, that required rectification. This paper describes the novel solution applied to these features that will allow for upstream face repairs to proceed without complete drawdown of the reservoir. The project provides a compelling example of “securing future resources”, and “sustainable dams” through works to extend the operational life of a 140 year old dam.