Independent Dam Safety Monitors - News & Updates
Dam Failure Hervey Bay Queensland Australia February and June 2008
The Automated Dam Crest Gates Failure in Hervey Bay Queensland Australia caused upstream inundation and flooding. In February and June 2008 it is understood that the Lenthalls Dam automated Crest Gates failed to operate as designed. The automated CrestGates and other works necessary for raising Lenthalls Dam where completed in February 2007. The Queensland Office of Water Supply Regulator confirmed the gate failures. Independent Dam Safety Monitors is aware that these dam gates are still not operational. Wide Bay Corporation manages the drinking water supply for the Fraser Coast Regional Council area (City of Maryborough, City of Hervey Bay and other smaller adjoining townships)- Lake Lenthal or Lenthals Dam is a major dam situated south west of Hervey Bay Queensland. Wide Bay Water Corporation is the dam constructing authority and are responsible for the design and operation of dam infrastucture and dam gate infrastructure.
The Wide Bay Water Corporation Annual Report for 2006- 2007 states that " the use of the CrestGates to increase the dam capacity is a first for Australia and will provide beneficial security to neighbouring properties in the event of a flood. The CrestGates will automatically drop during a major flood event to prevent upstream flooding and they will do so without the need for complex mechinical or electronic controls that could fail at the most critcial time".
The CrestGates failed on 2 occasions. The dam CrestGates failed even though it was not a major flood. When the dam gates failed upstream flooding did occur, Wongi Waterholes were inundated, lives were endangered. What will happen when there is a major flood?
Australia has a good repuation for dam safety and it may be the first instance in Australia where major water infrasture such Lenthals Dam (which is the City of Hervey Bays' primary drinking water supply) is allowed to be commissioned even though the necessary operational protocols, appropiately trained staff were lacking, operational procedures, safety manuals, documentation required by the Queensland Office of Water where incomplete and in DRAFT at the time of both failures. The necessary operational procedures were not conducted to ensure that Lenthals Dam and the CrestGates will operate as designed and not fail in the first flood event in February 2008 and the fail again a few months later in June 2008.
These failures in Queensland, Australia demonstrate that there is the need to reform and for The Guidelines on Risk Assement and Management to be updated. The ANCOLD Conference being held on the Gold Coast in November 2008 is a good opportunity for the Dam Industry to update their Dam Safety and Risk Management procedures and guidelines.
These CrestGate failures are an opportunity for the industry to take on board that automation of dam infrastructure is not necessarily the means to reduce risk, nor will automation ensure dam safety and reduced cost to operators, if operations do not perform their due diligence. Human factors and human behaviours is an element of dam failure. The Dam Safety Inspection Manual 2003 states that "human behaviour is an element of dam failure, simple mistakes, operational mismangement, unnecessary oversights or destructive intent can compound the possibility of dam failure" Part 1, Chapter 5.0 8/23/03 5-13 Dam Safety Inspection Manual Indiana Department of Natural Resources.
New Leglislation need to be implemented to ensure that Dam Safety regulators can enforce their legislation and ensure compliance by all dam operators including local government corporation such as Wide Bay Water Corporation.
For the Lenthalls Dam Gates Failure research paper and the blank Emergency Action Plan, please refer to the links below. (requires Adobe Reader)
Click here to read the report and click here to view the blank emergency action plan
Click here to read an extract of the Wide Bay Waters Operation Manual DRAFT version, the Chief Executive Officers Responsibility.
Click here to read Wide Bay Burnett Conservation Council's letter to the Minister