Picture: Lake Fyans

Review of February 2017 Operations

No measurable inflow was observed to reservoirs for a third consecutive month during February. Between July and February 67,250 ML of inflow has been recorded into headworks storages, which is 39% of the historic average for the same period (172,400 ML).

During February, the volume in headworks reservoirs decreased from 303,960 ML (54.3%) to 283,700 ML (50.6%).

On 24 February 2018, the Storage Manager commenced a transfer of approximately 2,000 ML from Lake Bellfield to Lake Fyans. This transfer targeted a period following local rainfall and forecasted mild temperatures to increase transfer efficiency. The transfer was initiated to secure water supplies in Lake Fyans, manage risks of adverse water quality, and support recreational pursuits.

Rainfall was below average at all reservoirs during February. The highest rainfall for the month was 18mm, recorded at Moora Moora Reservoir.

Environmental water releases continued during February, with 680 ML supplied from Lake Wartook to the MacKenzie River, and 260 ML released from Lake Lonsdale to provide baseflows to the lower Mt William Creek. Environmental water releases from Taylors Lake delivered 910 ML to the Wimmera River and Rocklands Reservoir released 3,290 ML of environmental water to the Glenelg River.

Wimmera-Mallee Pipeline supplied Recreation Lakes received 233 ML during the month.

Consumptive entitlement holders collectively used 1,610 ML during February to supply urban and rural demands.

Due to below average rainfall, net evaporation from reservoirs was approximately 7,600 ML for the month; with evaporation exceeding rainfall, (Net evaporation considers rainfall on the reservoir as an evaporation offset).

Planned March 2018 Operations

The Bureau of Meteorology(BoM) in their most recent climate outlook predict a 40% chance of above average rainfall this March. Current predictions are also for El Niño–Southern Oscillation (ENSO) to continue to weaken throughout March, with only 50% of climate models showing La Niña conditions will persist until the end of the month. La Niña events have historically brought above average rainfall to south eastern Australia during summer, however the weakening nature of the current La Niña conditions mean that there is not likely to be a significant influence on rainfall. La Niña events can also increase the likelihood of prolonged warm temperatures.

The Storage Manager will conclude the Lake Bellfield to Lake Fyans transfer on 8 March. While there are no further transfers planned for this month, the Storage Manager will continue to monitor conditions. Further information in relation to water transfers are described in the Storage Manager’s Annual Operating Plan.

The release of environmental water and the routine delivery of water to consumptive entitlement holders is expected to be the Storage Manager’s operational focus during March.

Reservoirs are expected to remain at suitable levels through March for a range of recreational activities, including boating at reservoirs where this is permitted. Please refer to the Reservoir information page for further information on water levels and recreation activities permitted at each reservoir.

Blue-Green Algae blooms can be more common during the warmer summer and autumn months. Recent Blue-Green Algae warnings for reservoirs can be found on the Storage Manager News Feed and all current warnings are available from the GWMWater Algae Warnings webpage.