Irrigation Allocations - April 2010
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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 were increased to 100% for the Murray system, 71% for the Goulburn system, and 17% for the Broken system. The allocations on the Bullarook (19%) and Loddon (3%) systems remained unchanged. The allocation for the Campaspe system remains at zero.
Irrigation Allocations across Northern Victorian
| 30 April 2010 | Change over the month | |
|---|---|---|
| Goulburn | 71% | +2% |
| Murray | 100% | +22% |
| Broken | 17% | +4% |
| Campaspe | 0% | 0% |
| Loddon | 3% | 0% |
| Bullarook | 19% | 0% |
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 first seasonal allocation outlook for the 2010/11 season on 15 February 2010. Due to poor correlation between low summer inflows and winter/spring inflow conditions, G-MW has based its seasonal allocation assessment on the full inflow record available. G-MW has produced outlooks for Dry, Average and Wet inflow conditions to illustrate the range of possible allocations. Wet inflow conditions = highest 10 percent of seasonal inflows over the historical record, average inflow conditions = the median seasonal inflows over the historical record and 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 one 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 release the next allocation outlook for the 2010/11 season on 17 May 2010. The first allocation announcement for the new season will be made on 1 July 2010.
Outlook at 15 February 2010 (percentage of high-reliability water share)
Outlook for 16 August 2010
| Inflow Conditions | Murray | Broken | Goulburn | Campaspe | Loddon |
|---|---|---|---|---|---|
| Wet | 69% | 86% | 73% | 100% | 100% |
| Average | 33% | 2% | 33% | 41% | 91% |
| Dry | 6% | 0% | 0% | 0% | 0% |
Outlook for 15 October 2010
| Inflow Conditions | Murray | Broken | Goulburn | Campaspe | Loddon |
|---|---|---|---|---|---|
| Wet | 100% | 97% | 100% | 100% | 100% |
| Average | 62% | 92% | 65% | 100% | 100% |
| Dry | 24% | 0% | 31% | 0% | 17% |
Outlook for 15 February 2011
| Inflow Conditions | Murray | Broken | Goulburn | Campaspe | Loddon |
|---|---|---|---|---|---|
| Wet | 100% | 100% | 100% | 100% | 100% |
| Average | 100% | 100% | 100% | 100% | 100% |
| Dry | 48% | 0% | 43% | 6% | 47% |
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 expected date for official completion of the pipeline is the end of May 2010. All trunk lines have now been installed and pressure tested. All that is remaining is the completion of the distribution lines that supply individual customers.
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 2 weeks. Normal supply will commence after pressure testing is completed in mid to late May.
The irrigation allocation is 0%.
Southern Rural Water
Macalister Irrigation District (MID)
At the end of April, Lake Glenmaggie, the main source of water for the MID, was at 41.2% of capacity.
The seasonal allocation in the MID remained at 100% of HRWS during April. On 6 April, SRW increased the allocation for low-reliability shares (LRWS) to 35%, and again on 20 April to 45%. The 2009/10 season will finish on 15 May, with the first allocation announcement of the new season due 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 14,958 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 volume recorded to date is less than 200 ML.
Latrobe System
At the end of April, the storage level in Blue Rock Lake was 76.6% of capacity.
The irrigation share of Blue Rock was 1,494 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 10% of capacity at the end of April.
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.
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.
Maribyrnong Basin
The storage volume in Rosslynne Reservoir remained very low at 4.5% of capacity at the end of April. SRW’s allocation for its licensed diverters remains at 0%.