Irrigation Allocations - May 2010
On this page
Goulburn-Murray Water (G-MW)
G-MW made the final allocation announcement for the 2009/10 season on 1 April. The allocations for high-reliability water shares finished the season at 100% for the Murray, 71% for the Goulburn, 17% for the Broken, 19% for Bullarook and 3% for the Loddon. The allocation for the Campaspe system remained at zero for 2009/10.
Irrigation Allocations across Northern Victorian
| Final Allocation 2009/10 | |
|---|---|
| Goulburn | 71% |
| Murray | 100% |
| Broken | 17% |
| Campaspe | 0% |
| Loddon | 3% |
| Bullarook | 19% |
The Minister for Water temporarily qualified rights to water in the Murray, Goulburn, Broken, Campaspe, Loddon and Bullarook systems this season to ensure there was enough water available for essential urban and farming needs.
As the allocations on the Goulburn and Murray systems are now above 20%, essential needs for domestic and stock use and industry are no longer covered under the qualification. The qualification to cover essential needs on the Broken, Loddon, Bullarook, and Campaspe systems will remain in place until a 50% allocation is reached.
Seasonal Allocation Outlook for Northern Victoria – 2010/11
G-MW released the latest seasonal allocation outlook for the 2010/11 season on 17 May 2010. The outlook is based on inflows observed following conditions experienced that were similar to this autumn. G-MW has produced outlooks for dry, average and wet inflow conditions to illustrate the range of possible allocations – refer to the tables below. G-MW has noted that the dry scenario does not represent a worst-case scenario for allocations (i.e. 2006/07 conditions). If extreme dry conditions are experienced, the allocations will be zero on all systems and delivery of carryover limited.
Wet inflow conditions = highest 10 percent of seasonal inflows over the historical record.
Average inflow conditions = the median seasonal inflows over the historical record
Dry inflow conditions = lowest 10 percent of seasonal inflows over the historical record
G-MW has advised that under dry and average inflow conditions, allocations are expected to be 0% for all systems on 1 July. Small allocations would be possible on some systems if wet conditions eventuated.
To put this outlook into context: in the 2009-10 irrigation season, inflows to Dartmouth (a major Victorian storage on the Murray system) and Lake Eildon (on the Goulburn system) were better than the dry inflow conditions, but were still closer to dry than average (inflows were in the lowest 20% of inflow records). Approximately a third of the irrigation allocation on the Murray this season was due to interstate inflows and the carryover rules, not inflows to Victorian storages. Furthermore, on the Loddon, Campaspe and Broken systems, inflows in 2009-10 were worse than the dry scenario provided in G-MW’s outlook.
G-MW will make the first allocation announcement for the 2010-11 season on 1 July 2010.
Outlook at 17 May 2010 (percentage of high-reliability water share)
Outlook for 16 August 2010
| Inflow Conditions | Murray | Broken | Goulburn | Campaspe | Loddon |
|---|---|---|---|---|---|
| Wet | 60% | 73% | 65% | 100% | 100% |
| Average | 31% | 8% | 37% | 0% | 91% |
| Dry | 23% | 0% | 7% | 0% | 0% |
Outlook for 15 October 2010
| Inflow Conditions | Murray | Broken | Goulburn | Campaspe | Loddon |
|---|---|---|---|---|---|
| Wet | 96% | 100% | 100% | 100% | 100% |
| Average | 65% | 85% | 69% | 36% | 57% |
| Dry | 46% | 5% | 37% | 0% | 0% |
Outlook for 15 February 2011
| Inflow Conditions | Murray | Broken | Goulburn | Campaspe | Loddon |
|---|---|---|---|---|---|
| Wet | 100% | 100% | 100% | 100% | 100% |
| Average | 100% | 100% | 100% | 52% | 19% |
| Dry | 74% | 20% | 50% | 6% | 0% |
Coliban Rural System
On 15 September, Coliban Water announced a 0% general allocation for the Coliban Rural System. Recycled water is available to customers on the Ascot and Axe Creek channel systems, equivalent to a 40% allocation.
The Minister for Water has qualified rights to water in the Coliban Rural System to allow Coliban Water to provide a 30% emergency supply to eligible customers.
Wimmera Mallee Domestic and Stock Supply System
All towns and rural customers connected to the pipeline are on Stage 1 restrictions except for four small towns supplied by Coliban Water which are on Stage 4.
The official completion date of the pipeline was 28 May 2010 when all pipe lines had been completed and only pressure testing of a few distribution pipelines remaining. Taylors Lake pumping station was still to be completed.
Towns and farms in supply systems 1, 2 and 5 are receiving full supply from the pipeline.
All towns in supply systems 3, 4 and 6 are now receiving piped supplies, as are several large supply by agreement customers. The final service connections are being made to 260 rural customers who will be able to receive an emergency supply through the pipeline when the tappings are completed in June. Normal supply will commence after pressure testing is completed towards the end of June.
The irrigation allocation is 0%.
Southern Rural Water
Macalister Irrigation District (MID)
At the end of May, Lake Glenmaggie, the main source of water for the MID, was at 37.7% of capacity.
The seasonal allocations in the MID finished at 100% for HRWS and 45% for low-reliability shares (LRWS). The first allocation announcement of the 2010/11 season will be made on 1 July. SRW anticipates storage volumes at the end the season being in a better position than last year.
The current volume in the Thomson/Macalister irrigators’ Thomson drought reserve is 15,313 ML.
A further qualification of rights is in place on the Thomson River. SRW is recording any loss of harvest rights, which will be offset by agreed arrangements to ensure irrigators are not disadvantaged. The offset volume recorded to date is less than 200 ML.
Latrobe System
At the end of May, the storage level in Blue Rock Lake was 75.5% of capacity.
The irrigation share of Blue Rock was 1,582 ML. SRW licence holders downstream on the Latrobe and Tanjil Rivers can pump up to their licence volume, but this is subject to the availability of unregulated river flows (which normally contribute approximately 70% of entitlements).
Werribee Basin
SRW’s share of the Werribee storages was at 9% of capacity at the end of May.
Southern Rural Water allocations remained 14% for HRWS in the Bacchus Marsh and Werribee irrigation districts.
Irrigators in the Werribee area continued to rely on the recycling scheme as their main water source while the river flows are very low. The recycling scheme is providing about 65 ML/day shared between 90% of Werribee growers. The first delivery of river water took place in late April.
While the situation across the whole Werribee basin remains serious, SRW is particularly concerned about Bacchus Marsh irrigators who do not have access to recycled water and rely on dwindling surface water resources and expensive emergency supplies. SRW is confident of being able to meet irrigators’ demands for the remainder of the season, with some water available to commence supply in the next season.
SRW predict being able to start the 2010/11 season with a 6% allocation for HRWS and around 400 ML of emergency water supplies carried over for Bacchus Marsh. The Government announced on 16 March that Werribee and Bacchus Marsh irrigators would be able to access up to 5 GL of Melbourne’s water as a drought contingency measure. Metropolitan water will be offered to customers in the coming season. In Werribee, this could help reduce salinity levels in the recycled water.
SRW expect that recycled water will continue to be the main source of supply for Werribee irrigators, unless there is a significant improvement in river water availability.
Maribyrnong Basin
The storage volume in Rosslynne Reservoir remained very low at 4.4% of capacity at the end of April. SRW’s allocation for its licensed diverters remains at 0%.