Bull Siphon during construction
Work on two key siphons in the Campaspe region are now complete after successful restoration and replacement works during the 2018 winter irrigation shutdown period.
The important improvements were made between May 18 and August 6, at the two work sites 5km apart along one of Goulburn-Murray Water’s (GMW’s) main carrier channels – the Waranga Western Channel.
Lead Project Manager Linc Wellington said the $2.5 million work on Bulls Siphon, which was designed and constructed ‘in-house’ by GMW, was delivered on time and about $200,000 under budget. The project involved removing the old deteriorated structure and replacing it with a new four-barrel three-metre diameter reinforced concrete structure.
“On August 6 we removed the coffer dams (the temporary dams) and water is now flowing as normal,” he said.
“The added bonus of carrying out these works ourselves was that we had control of project timeframes and schedules. Some minor out-of-channel works are still happening so customers may see our staff in the area for a couple of weeks yet,” he said.
At Campaspe Siphon, the coffer dams were removed on August 4. The three existing siphon barrels have been re-lined with fibre-reinforced concrete. The barrels allow water from the Waranga Western Channel to pass under the Campaspe River without interference.
“The newly-relined siphon barrels are now in use. We’re happy to say this project was also completed on time and within our $3.7 million budget,” Mr Wellington said.
“This project was originally intended to be carried out over two winter periods but we were able to make some project innovations and find a way to complete the works this winter. This has saved us a lot of time and costs for remobilisation.”
He said the contractor, Downer Pipetech, have been carrying out final site clean-up works.
“They were very accommodating in terms of having a stream of site visitors who were keen to look at the barrels and the re-lining work.”
Managing Director Pat Lennon said the works will ensure the historic assets continue to provide service to both Rochester and the Loddon Valley Irrigation Districts well into the future.
“Campaspe Siphon was first built in the early 1900s and was nearing the end of its serviceable life, which is why these works needed to happen. Ongoing patch works have taken place in previous years but this will be the first time since construction that significant upgrades have taken place,” he said.
“Our adoption of an innovative re-lining approach for Campaspe Siphon, utilising fibre-reinforced concrete, represented a large cost-saving for customers.
“The replacement cost of this infrastructure was estimated to be in the vicinity of $12 million, so coming in under $4 million was a great result.”
Mr Lennon said Bulls Siphon had similarly experienced significant deterioration and was at the end of its life prior to this winter’s refurbishment.
“These successful works are a credit to the project teams.”
The irrigation season officially began August 15.