About Waranga Basin
Waranga Basin is an important off-river storage, where water is diverted from the Goulburn River at Goulburn Weir, via the Stuart Murray Canal and Cattanach Canal.
The Basin also has a small catchment area of its own and with a capacity of 432,360 ML and is one of the largest storages in the Goulburn System.
Location
Waranga Basin is located between the Goulburn and Campaspe River basins, approximately 8 km north-east of Rushworth.
History
Waranga Basin was completed in 1915, ten years after construction began. It was constructed using picks, shovels and horse-drawn scoops, and at the time of construction, was described as the largest project of its kind in the world, with an embankment height of 8.8 m and length of 7.0 km.
Between 1915 and 1926, the embankment was raised in stages, and a core wall was inserted. The capacity at the end of the second stage of construction was 432,360 ML.
Operations
The water stored in Waranga Basin supplies the Central Goulburn, Rochester and Pyramid-Boort irrigation areas across northern Victoria. Supplies to the Rochester and Pyramid-Boort areas occur via the 180 km long Waranga Western Channel.
The volume of water in store is mainly regulated. All discharges take place through channel outlets. The Major Outlet has a discharge capacity of 4,200 ML/d, and the Minor Outlet discharge capacity is 1,850 ML/day.
In the 2006/2007 Irrigation Season, the Goulburn System experienced the worst drought on record. Water available to Goulburn-Murray Water customers was approximately half that available in the previous ‘worst' year which occurred in 2002/2003.
Normally, only about three-quarters of Waranga Basin's capacity of 432,360 ML can be used by gravity flow from the Basin's two outlets. In February 2007 as well as in 2003, Goulburn-Murray Water pumped up to 90,000 ML of water from below the normal minimum operating level in Waranga Basin to assist drought stricken farmers in the Goulburn Irrigation System. Pumping of the Basin has only occurred three times: 2007, 2003 and 1926. The 2007 operation is estimated to have cost around $4.3 million. This project was a part of a range of measures Goulburn-Murray Water implemented to maximise the amount of water available for use in such a dry year.