Review of March 2017 Operations
There was no measurable inflow was received into any headworks storage during March. Year to date inflows (July – March) remain at 241,500 ML, which is 139% of the average for the same period (174,200 ML).
During March, the volume in headworks reservoirs declined by 18,820 ML, from 318,100 ML (57%) to 299,280 ML (54%).
Rainfall during March ranged from 25 mm at Moora Moora Reservoir to 14 mm at Lake Fyans.
A blue-green algae warning was issued for Taylors Lake during early February. Warning signs were erected at the lake, with the public advised to avoid contact with affected water. Elevated levels of blue-green algae persisted until early March, after which time the warning for Taylors Lake was able to be removed.
A Blue-Green Algae warning was also issued for Lake Toolondo. Regular monitoring will continue, with updates available from GWMWater’s website (www.gwmwater.org.au). (High levels of Blue-Green Algae, often referred to as a ‘bloom’, can make water unsuitable for both consumption and direct skin contact through recreational activities.)
A transfer of 1,200 ML from Lake Bellfield to Lake Fyans occurred during March. The transfer provided freshening flows to Lake Fyans to improve water quality, and also provides recreation benefit through increased water levels.
Environmental releases continued from Lake Wartook, Rocklands Reservoir, Lake Lonsdale, and Taylors Lake during March. A total of 1,059 ML environmental flow was delivered from Lake Lonsdale to Mt William Creek, and 1,794 ML from Rocklands to the Glenelg River. The MacKenzie River downstream of Dad and Dave Weir received 696 ML of environmental water from Lake Wartook, and 827 ML was released from Taylors Lake to the Wimmera River.
Consumptive entitlement holders collectively used 1,511 ML during March to supply urban and rural system demands.
Net evaporation from reservoirs was approximately 6,500 ML for the month.
(Net evaporation considers rainfall on the reservoir as an evaporation offset.)
Planned April 2017 Operations
The Bureau of Meteorology is predicting drier than ‘average’ Autumn conditions over the coming three months. The Bureau’s El Niño–Southern Oscillation (ENSO) indicator has been upgraded to “El Niño watch” which indicates around a 50% chance of El Niño conditions developing during 2017. El Niño events have historically resulted in below average rainfall across south-eastern Australia.
It is expected that without significant rainfall, there will be little to no measurable inflows to reservoirs again during April.
Delivery of accumulated environmental passing flow commitments to the Glenelg River will conclude in early April, upon delivery of all remaining accumulated volume.
Delivery of regulated environmental flow to MacKenzie River, Burnt Creek, Mt William Creek, Wimmera River, and Glenelg River is expected to continue through April.
The routine delivery of water to consumptive entitlement holders will be ongoing.
The Storage Manager will continue its regular monitoring of reservoir levels, weather forecasts and waterways during April. Regular monitoring for Blue-Green Algae at headworks reservoirs is ongoing through the summer and autumn months.
Reservoirs are expected to remain at suitable levels through April for a range of recreational activities, including boating at reservoirs where this is permitted. Please refer to the
Reservoir Level information page for further information on water levels and recreation activities permitted at each reservoir.