2009 – Spillway Upgrade Program in Queensland

Khanh (Ken) Nguyen, Peter Allen

There is community concern regarding the potential for dams to fail and threaten lives. In Queensland, the Water Supply (Security and Reliability) Act 2008 provides for the regulation of dams whose failure could cause loss of life. Other consequences of dam failure such as interruption of services, economic loss and damage to the environment would also be of paramount importance for the safety management of our dams in the current climates of change.

In 2003, the Bureau of Meteorology (BoM) revised the Probable Maximum Precipitation (PMP) estimates for both short and long durations of extreme rainfalls for northern Australia. As a consequence, the majority of cases resulted in a significant increase of extreme flood estimates for many river catchments in Queensland. Subsequent studies by the BoM have investigated the potential impact that climate change might have on PMP estimation.

This paper examines the current progress of the Queensland Spillway Upgrade Program, by discussing the current regulatory environment and identifying a number of hydrological issues which may require further investigation for Queensland conditions.

Keywords: Spillway Upgrade, Acceptable Flood Capacity, Flood Discharge Capacity.