Loch Garry rules to be reviewed

Procedures: There are 48 bays in the Loch Garry structure.

Goulburn-Murray Water says it will review operation of its Loch Garry infrastructure after the current floods subside.

Loch Garry provides protection from minor to moderate flooding for landholders along the lower Goulburn River.

The current operating rules require G-MW to start removing the 480 bars at the structure, about 20km north of Shepparton, when the Goulburn River reaches 10.36m at Shepparton.

The operating rules require progressive removal of the bars (25 bars removed for every 31mm increase in river height) at Loch Garry 24 hours after the river height exceeds 10.36m on the Goulburn River’s Shepparton gauge. All bars are to be removed from the structure 24 hours after the river height reaches 10.96m.

The Goulburn River reached 10.36m at the Shepparton gauge at noon on Saturday, October 15 and G-MW staff began removing bars from Loch Garry at noon on Sunday, October 16.

“At this stage, the loch water level was quickly rising,” G-MW emergency controller Peter Clydesdale said last week.

“Staff were able to remove approximately half of the bars at the loch before rising water levels meant it was physically impossible and unsafe for them to continue.”

The Goulburn River peaked at 12.05m on October 16, well above the major flood level of 11m.

G-MW said it was standard protocol to review operating procedures after major flood events.

It said it would consult with Loch Garry customers and relevant agencies to undertake a review of the operating rules, including the notification process and adaptability of the rules to factor in unprecedented flooding.

On Friday, October 21, G-MW was removing flood debris from the Loch Garry structure and started re-instating the bars on Saturday, October 22.

The Goulburn River at Shepparton was steady at 10.57m (below moderate flood level) on Saturday afternoon.