Lenthall Dam gates open
WHILE places like the Mary River valley, Charleville, Roma and Mitchell struggled to come to terms with varying degrees of flooding yesterday, the Fraser Coast was denied that problem by some high-tech hydrological engineering.
Flooding rains in the Wide Bay have caused the innovative crest gates at Lenthall Dam, outside Hervey Bay, to open automatically for the first time, saving the lake foreshore and areas upstream from flooding.
“This shows the true value of the crest gate system we chose to install in order to increase the capacity of Lake Lenthall,” Wide Bay Water CEO Tim Waldron said.
“This is the only dam system in Australia that stops other land from being inundated.
“Every citizen on the Fraser Coast should be proud to be associated with an Australian first.
“If all other dams were built this way we wouldn’t be seeing some of the flooding that’s occurring now in Qld.”
Gate 3 at Lenthall Dam opened automatically at 2.30am yesterday when the dam level was 120mm above the crest level which is the design criteria.
WBW installed the crest gates in 2007 in order to increase the capacity of Hervey Bay’s main reservoir from 17,800ML to 29,500ML, ensuring the city’s water supply until approximately 2025.
WBW discovered the concept by chance in South Africa.
“Our use of crest gates was an Australian first and the benefits of that decision are being seen in this current load of wet weather,” Mr Waldron said.
“The crest gates allow water to flow through as if there wasn’t a dam in place and this provides a flushing effect to the Burrum River downstream which gives environmental benefits.
“It also prevents the flooding of upstream land which preserves habitats, sensitive areas like Wongi Waterholes and any nearby properties. And from a delivery point of view it allows us to quickly restore the lake to its operating level as the flood dissipates.
“These flood conditions were the final criteria for the testing of its raising and will be acknowledged by the dam regulator.”