T2022-25 Risk Review - Chinaman Creek Dam

Summary and scope

Chinaman Creek Dam is owned and operated by Cloncurry Shire Council. The Dam is located on Chinaman Creek, 600m upstream of its junction with the Cloncurry River on the outskirts of Cloncurry. The dam consists of a concrete gravity dam and spillway with a 2km long earth levee embankment, which impounds a storage of 2.75 GL at full supply level. The main concrete gravity dam is approximately 153m long and 15m high. The earth levee embankment is of zoned earth-fill construction type with a maximum height of approximately 7m above foundation level. The dam was constructed in 1993 to provide affordable water security to the town of Cloncurry. Currently, the dam is predominantly used for tourism, sport and recreational purposes. The dam is classified as a Category 2 referable dam in accordance with the Water Act 2000 and has been a Consequence Category of High A in accordance with relevant State and National Guidelines. In the event of a dam failure, according to the most recent Failure Impact Assessment (FIA), Chinaman Creek Dam has a PAR of 197 for the Probable Maximum Flood (PMF) event. The dam currently meets only 41% of the Acceptable Flood Capacity (AFC). This measure has been determined using a standards-based assessment approach. Council is required to reach 65% of AFC by October 2025. Council is now seeking to engaged a suitably qualified consultancy to complete a comprehensive risk review of Chinaman Creek Dam (a risk-based approach) in line with relevant guidelines (ANCOLD, the Guidelines on Safety Assessments for Referable Dams and the Queensland Dam Safety Management Guidelines). This review will provide Council with the necessary infrastructure and non-infrastructure investments required to enable Council to achieve 65% of AFC by October 2025.