Irrigation Allocations - Spetember 2007
On this page
Goulburn-Murray Water (G-MW)
G-MW made its latest allocation announcement for the 2007/2008 season on 1 October. Current allocations for high reliability water shares are as follows:
| 1st October 2007 | 3rd September 2007 | 1st August 2007 | |
|---|---|---|---|
| Goulburn | 23% | 17% | 0% |
| Murray | 16% | 5% | 0% |
| Broken | 15% | 10% | 0% |
| Campaspe | 1% | 0% | 0% |
| Loddon | 5% | 0% | 0% |
| Bullarook | 0% | 0% | 0% |
G-MW increased the allocation to 23% and extended the irrigation season length in the Goulburn system to 30 April 2008. This means that the trigger for expiry of most of the conditions in the qualification of rights in the Goulburn system has been reached and most normal operating rules now apply.
Inflows to the Murray system provided the resource for allocations to increase to 16%. The close of the irrigation season remains at 15 March 2008.
Lower than planned storage releases on the Broken system have enabled allocations to be increased to 15%. Loddon system customers received an allocation of 5% of high-reliability water shares. Delivery restrictions on both systems were lifted to allow diversions throughout the season. Continuous access to water is available until 31 October 2007, with access after 31 October to be rostered to ensure efficient use of limited resources in these systems.
A 1% allocation was announced on the Campaspe system. All orders on the Campaspe will be rostered to minimise system losses.
There is not enough water in the Bullarook Creek system to meet qualified right commitments for the whole season. G-MW is assessing bridging allocation options.
The seasonal outlooks for all systems have declined as recent rainfall totals remain well below average. Inflow volumes to the major storages are now less than those assumed for the ‘Dry' conditions and an additional ‘Very Dry' outlook has been provided in the outlook table.
The latest allocation outlooks for 15 December under a range of conditions are given below:
| Very Dry Conditions (9.9 out of 10) |
Dry Conditions (9 out of 10) |
Ave. Conditions (5 out of 10) |
Wet Conditions (1 out of 10) |
|
|---|---|---|---|---|
| Goulburn | 24% | 32% | 51% | 87% |
| Murray | 18% | 23% | 40% | 53% |
G-MW will provide the next allocation announcement on 15 October 2007.
G-MW has relaxed the rules to allow allocation trade from upstream of the Barmah Choke downstream to other stretches of the River Murray. Trade is usually restricted because the Choke restricts the amount of water that can be transferred to downstream users through this stretch of the River.
G-MW has received support from Goulburn irrigators for the pumping of Waranga Basin to allow for an early allocation on the system.
The Minister for Water has temporarily qualified rights to water in the Murray, Goulburn, Broken, Campaspe, Loddon and Bullarook systems under section 33AAA(1) of the Water Act 1989. This means that water can be taken from these supply systems for selected purposes, even whilst the allocation to high reliability water shares is low.
Once allocations reach 20% on the Murray and Broken systems, and 50% on the Campaspe, Loddon and Bullarook systems, normal operating rules will resume.
G-MW has declared a Water Shortage in the Spring Hill Water Supply Protection Area (WSPA) and announced seasonal groundwater allocations for the Area in response to ongoing dry conditions and the need to limit the stress on the aquifer and ensure access for all groundwater users.
Coliban Rural System
This year’s Coliban System rural season opened with a 30% allocation of licensed volume. The allocation for rural customers is the minimum needed to run the rural system with some efficiency. As of 1 October, Coliban system headworks were holding 17.7% of capacity.
Wimmera Mallee Domestic and Stock Supply System
Inflows to Grampians Headworks storages have dropped off following below average rainfall in the past four months.
At 30 September 2007, storages in the Wimmera Mallee domestic and stock supply system were at 8.0% of capacity.
GWMW began the winter channel run in September with the aim of filling occupied house dams on all winter channels that will not be piped in the next 12 months.
Stock and Domestic customers who do not have house dams can fill one dam per enterprise. In addition, intensive industry customers supplied by the channel system will be entitled to 50% of their supply by agreement entitlement, or their intensive industry water use.
Water carting to properties receiving a dam fill will be withdrawn once each dam has been filled. Water carting permits will still be issued in cases where people do not receive a dam fill but need water for stock and crop spraying needs.
GWMW expects that about 2,500 dams, or 18% of the total number of dams in the channel system, will be filled. Customers on the Wimmera Mallee pipeline systems 1 and 5 will not be supplied a dam fill; however carting in those areas will continue until they get a pipeline supply later this year.
Customers that are supplied by the irrigation channel system and the summer dam fill area will need to wait until later in the season for an announcement concerning the running of the summer system which is not normally activated until November.
Full details of the cartage program are available on GWMW’s website. In summary:
- GWMW is currently delivering 11 ML of water for domestic use every two months. This amount is expected to reduce marginally over time as house dams on the winter channel run are filled.
- The purchase of a water tank is eligible for up to a $3,000 rebate from the Victorian Government.
- Additional water is also available to GWMW rural customers, including those who receive a house dam fill, for stock watering and crop spraying. Water is provided at no cost, but carting arrangements and costs are the customer’s responsibility.
- Water is also available at a cost of $1.20/kL under a permit system for carting by others (at their own cost) who are not customers of GWMW. This water is for domestic use only.
Supplies to all customer groups are being made available in accordance with the restriction schedule contained in the Wimmera-Glenelg Bulk Entitlements. Restrictions are as follows:
- towns are on Stage 4 restrictions;
- irrigation supplies are again zero;
- no supply is available for irrigation diversions on Wimmera River; supply to recreation lakes has been nil since 2000.
GWMW began releasing environmental flows (60 ML/day) of 2005/06 carry over water on 25 September to maintain the last remaining drought refuge areas in the Wimmera River for threatened cat fish species, blackfish and river red gums. In 2006 this flow was held over for emergency purposes until there was sufficient water in Grampians storages to permit a channel run.
Southern Rural Water
Macalister Irrigation District (MID)
Lake Glenmaggie, the principal source of water for the MID, is now at 92.9% of capacity. SRW was recently maintaining the lake just below full capacity to assist with the management of inflow peaks associated with rain events, but with dry conditions in recent weeks, the need for this buffer has diminished.
The 2007/08 irrigation season opened on 15 August with an allocation of 100%. Recent dry conditions saw off-quota water finish in early September. Off-quota is normally available well into spring. Inflows will need to improve to achieve this.
In the absence of further off-quota water becoming available, any increase in the allocation will depend on further inflows over summer and autumn.
Latrobe System
Water availability on the Latrobe system increased throughout September with Blue Rock Lake increasing to 74.3% of capacity. However, the current irrigation share stands at just 2,090 ML, or 20% of regulated allocation, due to being drawn down last season.
Southern Rural Water (SRW) license holders downstream on the Latrobe and Tanjil Rivers can currently pump up to their licensed volume from unregulated flows (which normally contribute some 70% of entitlements). SRW will announce a formal initial allocation for the 2007/08 season when unregulated flows in the Latrobe reduce to the minimum environmental flows.
Werribee Basin (Bacchus Marsh and Werribee Irrigation District)
SRW’s share of the Werribee Basin storages rose to 11.6% of capacity during September (an increase of just 0.4% since 31 August). This level is low for this time of year.
SRW made an opening seasonal allocation for 2007/08 on 1 July of 0% water right and 100% domestic and stock. SRW has committed to pumping dead storage from Pykes Creek reservoir, which has enabled the allocation to be increased to 5% water right for the system.
Whilst inflows to the storages during July were promising, they have tapered off since mid-July due to a lack of consistent rainfall. This is of some concern, as allocations for irrigation are historically dependent on winter/spring inflows.
A range of measures are in place to assist in ameliorating the supply situation:
- Irrigators in the Werribee area will continue to participate in the recycling scheme. Some 7,300 ML of recycled water was delivered to approximately 85% of all growers last season. However, some irrigators have expressed preference for the use of some river water to allow shandying.
- A Ministerial-approved revision of the depth boundary for the Merrimu GMA has allowed for additional access to groundwater for Bacchus Marsh growers.
- The Minister for Water allocated 1,200 ML of unallocated water in Merrimu Reservoir for use up until September 2007 to maintain business viability in Bacchus Marsh. SRW are seeking an extension of this allocation.
SRW is also considering transferring water from the drought reserve in the Thomson reservoir.
Levels in the Deutgam Groundwater Management Area declined through 2005/06 and again during 2006/07, despite very low allocations. In order to protect the resource from seawater intrusion SRW have qualified and suspended rights, effectively banning groundwater use in the GMA as of 27 June 2007. SRW continue to monitor the situation.
Maribyrnong Basin
The storage volume in Rosslynne Reservoir decreased slightly throughout September and remains low at just 5.0% of capacity. With inflows well below average, SRW diverters face another season of low, possibly zero, allocations.
SRW announced an initial allocation of 0% of licensed volume for the 2007/08 season on 3 August.