Coliban Water prepares for once-in-a-decade maintenance work

For the first time in almost a decade, Victoria’s Kalimna Basin will be drained and inspected as part of maintenance works on Castlemaine’s water supply network. 

Coliban Water is preparing the inspection of the basin, which is an enclosed clear water storage that receives treated water from Castlemaine Water Treatment Plant and then supplies the network via gravity when the basin levels are full.

Coliban Water Manager Customer Operations Steve Dunlop said the major inspection hasn’t been undertaken at the site since 2011.

“We have an ongoing program of cleaning and maintaining our storages, but a major inspection such as this is only required every decade,” he said.

“This proactive work is about ensuring our assets are in the best condition possible and continuing to provide safe, clean drinking water to our customers.”

Testing will take place at the end of June to ensure the basin can be drained without impacting customers. Following testing, the drain, clean and inspection – including a major condition assessment – is planned for early July.

Dunlop said the utility is also taking the opportunity to upgrade the important infrastructure. 

“In addition to the cleaning and inspections we are undertaking, we are also installing a new mixer in the basin,” he said.

“The mixer will ensure water age and disinfection levels are very consistent throughout the entire basin, which improves the uniformity of water that is delivered to our customers throughout the network.”

Furthermore, Dunlop said the utility has made significant changes in the monitoring and daily operations of the network.

“This has been to ensure we minimise the impact to customers of any taste or smell associated with the water supply, and ensure disinfection levels are maintained throughout the network,” he said. 

“One of the key changes made is ensuring the basin fills outside of peak times seen in the morning and evenings each day.

“These works that will be undertaken will not interrupt water supply, nor change our treatment process, but some customers may notice a change to the taste and smell of the water, with the water supply coming directly from the treatment plant during this time, along with the possibility of some minor fluctuations in water pressure.”