Very wet conditions in 2016–17 replenished storages across northern Victoria, resulting in good allocations at the start of 2017–18. Conditions in 2017–18 were mostly warm and dry, and as of May 2018, rainfall was needed to wet-up most catchments before there could be significant run-off into waterways and storages. Forecasts leading into the 2018–19 water year are generally neutral, with no clear indication of whether winter and spring 2018 rainfall will be above or below average.
Each year on 15 May, the Northern Victoria Resource Manager releases a water availability outlook for northern Victoria for the coming year. These seasonal outlooks are updated monthly once the season begins, and are available at www.nvrm.net.au.
The 2018–19 outlook at 15 May 2018 indicated that early-season water availability is expected to be moderate in most systems. The opening, high-reliability entitlement allocation is expected to be at least 20 percent in the Goulburn and Loddon systems, 40 percent in the Murray system and 100 percent in the Campaspe system, with all systems expected to reach 100 percent by October 2018 under average conditions. Under an extreme dry to dry scenario – that is, if inflows are similar to the lowest 1 to 10 percent of inflows on record — most systems are unlikely to reach 100 percent high-reliability allocation. Allocation against low-reliability entitlements is possible in 2018–19 under average-to-wet conditions.
Demands for water for the environment in northern Victoria are usually highest in winter and spring. Opening allocations combined with some carryover should be sufficient to meet expected environmental demand for winter flows in creeks and rivers, as well as floodplain watering of Gunbower Forest. In 2017–18, a large volume (around 250,000 ML) of RMIF water was released from the Snowy storages because of Snowy Hydro releases for electricity generation. A portion of this RMIF was used in 2017–18 for environmental outcomes in the Murray system, with the remainder carried over to meet 2018–19 environmental demands in Victoria, NSW and SA.
Large rainfall events may result in unregulated flows that meet or exceed many of the environmental water flow targets in downstream waterways. Unregulated flows can reduce the amount of water for the environment that needs to be delivered to meet the highest-priority objectives, allowing additional watering actions during the year. However, if spills from storages occur, some or all unused water carried over from 2017–18 may be deducted from environmental water accounts.
What is the Basin Plan 2012?
Northern Victoria is a part of the Murray–Darling Basin and deliveries of water for the environment in the Northern Region are subject to the requirements of the Basin Plan 2012, also known as the Murray–Darling Basin Plan. The MDBA developed the plan under the Commonwealth Water Act 2007 and it became law in November 2012. The plan sets legal limits on the amount of water that can be taken from the Murray–Darling Basin's surface and groundwater resources. Chapter 8 of the plan also sets out a high-level environmental watering plan, which defines environmental objectives to protect, restore and build the resilience of water-dependent ecosystems and their associated functions. The VEWH's environmental planning and delivery is consistent with the requirements of the plan. The potential environmental watering outlined in sections 4 and 5 of this seasonal watering plan fulfil Victoria's obligations to identify annual environmental watering priorities for Victoria's water resource areas under section 8.26 of the Basin Plan 2012.