Gate upgrade follows more than 50 years of service

Monday 22 July, 2019

Major works on infrastructure critical to the operation of the Stuart Murray Canal at Goulburn Weir have been completed on time and under budget.

Four radial gates on the canal’s offtake regulator have been successfully replaced with new steel structures – ensuring accurate irrigation deliveries to hundreds of farmers in the Central Goulburn irrigation area.

Originally installed in 1967, the old gates were nearing the end of their operational life and had become rusty, degraded and required replacement.

Goulburn Murray Water (GMW), which manages the infrastructure, has been working with Shepparton contractor Fast Track Fabrication and Design since May to remove the old gates, replicate replacement gates and install the new structures.

In the last week, the new gates have been tested in wet and dry conditions and are now ready for the irrigation season.

“As we had to drain the Stuart Murray Canal in order to replace these gates, it was critical to our customers that we complete this work during winter, outside the gravity irrigation season,” GMW Manager Dams Operations Scott Wikman said.

“This has been successful, the canal will be refilled and the structure is ready for the opening of the irrigation season on August 15.”

To allow for the works, Mr Wikman said GMW also slightly lowered Lake Nagambie’s water level which would now be returned to its normal level.

Like many components on GMW’s older irrigation infrastructure, the new radial gates had to be built from scratch and required modern innovation to reproduce their size and shape.

Fast Track Fabrication and Design Director David Molloy-Hunt said modern computer design techniques allowed his firm to replicate the gates with pinpoint accuracy.

“We also used modern paint protection, which has different specifications depending on its exposure to water,” he said.

Both Mr Molloy-Hunt and Project Manager, GMW Senior Engineer Ben Ross, said the project ran extremely smoothly.

“We ran ahead of schedule and these new gates will last for another 50 years, at least,” Mr Ross said.

The Goulburn Weir and its adjoining recreational area remained open and accessible throughout the upgrade; however, for safety reasons, the Stuart Murray Canal’s offtake structure, walkover and adjoining carpark had to be closed.

“These have now reopened to the public,” Mr Wikman said.

“This major GMW Winter Works project saw some heavy vehicle traffic in the area in recent weeks and we thank residents and visitors for their understanding.”

The Stuart Murray Canal transfers water from the Goulburn River at the Goulburn Weir near Nagambie, through the rural areas around Murchison and Dhurringile, to the Waranga Basin near Rushworth.

Originally constructed with the main weir in 1890 and upgraded in the 1960s, the Stuart Murray Canal’s offtake structure is located on the western side of the weir.

The offtake originally consisted of 20 vertical steel butterfly gates. During its 1967 upgrade, 10 of these gates were replaced with four radial gates that have now, in turn, been replaced 52 years later.