Murray, Broken and Campaspe Seasonal Determinations Increase

Determination Data

Seasonal determinations for northern Victoria regulated river systems.

Further Information

The Resource Manager for northern Victorian regulated water systems today announced an update to the seasonal determinations for the 2012/13 season.

The Murray system seasonal determination is 75% of high-reliability water shares (HRWS), an increase of 14%. The Broken system seasonal determination has increased by 1% to be 45% HRWS. Campaspe system customers have a seasonal determination of 100% HRWS and a seasonal determination of 65% of low-reliability water shares (LRWS), an increase of 11% LRWS.

The seasonal determination in the Goulburn and Loddon systems remains unchanged at 100% HRWS. The Bullarook system seasonal determination also remains unchanged at 100% HRWS and 100% LRWS.

“Irrigation deliveries have increased with the recent warmer weather. These deliveries have occurred mainly from unregulated flows rather than planned release from storages, which increases the volume of water available in storage to make seasonal determinations in the Murray system and increases the reserves in the Goulburn and Loddon systems,” said Dr Mark Bailey, Resource Manager.

Approximately 83,500 ML has been pre-released from Lake Eildon, and about 10,400 ML has spilled from Goulburn-Murray Water’s share of Lake Eppalock in the past fortnight. The pre-releases from Lake Eildon are treated as a spill from storage. The volumes in spillable water accounts in the Goulburn and Campaspe systems have been reduced as a result. Where possible, pre-releases from Lake Eildon are being harvested for use within the Goulburn system.

“No spills have occurred from Lake Dartmouth in the Murray system. The level at Lake Dartmouth is still rising and the storage is holding more than 95% of capacity, which indicates a high risk of spill exists. Any pre-release or physical spill from Lake Dartmouth will reduce spillable water account volumes, allowing all storage inflows to contribute to increased seasonal determinations.”

Outlook for the 2012/13 Season

Under average conditions, seasonal determinations in the Murray system are expected to reach 100% HRWS by 15 December 2012. Under dry conditions, the season determination in the Murray system is expected to be 100% HRWS by 15 February 2013.

In the Broken system, customers are expected to receive a seasonal determination of 100% HRWS by 15 December 2012 under dry conditions. Under average conditions, the seasonal determination is expected to reach 100% HRWS during spring. Low-reliability water shares are also expected to receive a seasonal determination of 100% in late spring under average conditions, or by 15 February 2013 under dry conditions.

“Seasonal determinations of low-reliability water shares in the Murray and Goulburn systems will depend on usage and the volume of inflows during spring. If inflows result in water being debited from spillable water accounts and water is used during periods of unregulated flows without release from storage, the chances of seasonal determinations of low-reliability water shares improve,” said Dr Bailey.

Under average conditions in the Campaspe system, customers are expected to receive a seasonal determination of 100% LRWS by 15 December 2012.

Upcoming Resource Manager Announcements

The next seasonal determination announcement will be issued on Monday 1 October 2012.

The next assessment of the probability of spill in the Murray, Goulburn and Campaspe systems will be issued on Wednesday 10 October 2012.