Vital siphon works on Waranga Western Channel to ensure ongoing water supply for Rochester and Loddon Valley area

Thursday 10 May, 2018

It will be all hands on deck this winter as Goulburn-Murray Water (GMW) crews and contractors upgrade two key siphons in the Campaspe region.

The project will see important improvements made to the Campaspe River Siphon and Bulls Siphon between May 18 and August 6. The work sites are located along one of GMW’s main carrier channels, the Waranga Western Channel, and are about 5km apart.

Project Manager Jarrod O’Brien said work on the Campaspe River Siphon will see the existing siphon re-lined with fibre-reinforced concrete to ensure the historic asset continues to operate and provide service to both Rochester and Loddon Valley Irrigation Districts.

“The siphon was built in the early 1900s and is nearing the end of its serviceable life, which is why it’s important these works take place. It features three barrels which allow water from the Waranga Western Channel to pass under the Campaspe River without interference.

“Ongoing patch works have taken place in previous years but this will be the first time since construction that significant upgrade works have taken place,” Mr O’Brien said.

Bulls Siphon

The Bulls Siphon

Campaspe and Bulls Siphon works map

A map of the Campaspe and Bulls Siphon works - click image to enlarge. 

The re-lining work will be carried out by contractor Downer Pipetech and will cost about $3.7 million - significantly less than if the whole structure were replaced, which would be in the vicinity of $12 million. The newly-lined siphon will provide a similar lifespan to a full replacement option.

“Work on nearby Bulls Siphon will involve removing the old structure and replacing with a new four barrel three-metre diameter reinforced concrete structure. This siphon has reached the end of its serviceable life.

“Bulls Siphon has experienced significant deterioration and has experienced considerably more failures compared to Campaspe. The residual strength in the original structure is much less which is why we the adopted replacement option,” Mr O’Brien said.

GMW will carry out the design and construction work on Bulls Siphon, which is estimated to cost $2.7 million.

“By carrying out these works it will remove the risk of failure and ensure we can continue to provide a reliable service to our customers,” he said.

Zegelin Road between Murdoch and Tasker Roads will be closed for the duration of the works at Bulls Siphon. Drivers are asked to take care on local roads as there will be trucks and heavy machinery moving through the area.

Managing Director Pat Lennon said there is an opportunity to complete the works on the Campaspe Siphon in one winter which would potentially save costs.

“It would also save the need for de-watering the channel again and mean less interruption to supply,” he said.

GMW’s planned work within the Capital Structures program is estimated to cost $10.5 million in the 2017/18 financial year. This includes work on 63 structures – with some work already completed.

“About 40 of these jobs are due to take place this winter. This work is split relatively evenly across GMW’s region with prioritisation of assets that need replacing or refurbishment,” Mr Lennon said.

GMW customers are reminded to make alternative arrangements for water supply during the irrigation off season/winter works period, as water supplied from the channel network is only guaranteed during the irrigation season.