G-MW prepares storages and Mildura Weir for potential rainfall this week

Wednesday 8 December, 2010

With some river systems already in flood and the Bureau of Meteorology forecasting 50 to 100 mm of rain later this week, Goulburn-Murray Water (G-MW) has begun preparations at some of its storages and is advising of increased river flows and a drop in the Mildura Weir pool.

G-MW is encouraging pump and houseboat owners, customers and members of the community to be prepared and to monitor the flood and river level warnings issued by the Bureau of Meteorology over coming days. 

G-MW acting Managing Director Shane McGrath said it was important to recognise that the water storages are for harvesting water resources. The water in the storages has been allocated to and is owned by irrigators, urban water corporations and other water users across the region.

"Where the design of the storage allows and where we are confident the rainfall will refill the storage, G-MW may pre-release water to provide some attenuation of flood flows," said Mr McGrath. "However, all operations are aimed at ensuring that these facilities meet appropriate and current safety standards."

G-MW's 16 storages range in age from 30 to more than 130 years, with a range of design and construction styles. Some storages have gates that allow G-MW to pre-release water; others are ‘fill and spill' storages with free over flow spillways to manage the outflows.

"With catchments already wet and storages at or close to full capacity we anticipate a rapid response in the storages and downstream river levels. Water levels and the outflows from storages will be determined by the location and intensity of rain and how quickly it falls and how quickly it runs off into the storages or downstream rivers," said Mr McGrath.

"Two weeks ago we recorded 120 mm in 48 hours at Cairn Curran resulting in a maximum inflow of over 50,000ML.  In contrast, 20 kilometres away at Tullaroop we recorded barely 4,000 ML of inflow.  It's a reminder that our plans and the plans of our customers need to allow for the fact that we are dealing with an unpredictable natural event," said Mr McGrath.

 

Key preparations underway by G-MW include:

Cairn Curran Reservoir G-MW this week began releasing 5,500 ML a day and intends releasing approximately 11,000 ML or 7.5% of the storage's capacity before predicted rain arrives.

"The releases are within the capacity of the river, but once the rain arrives, the need for increased releases will be determined by the volume of water flowing into the storage and in accordance with the local operating rules," said Mr McGrath.

Mildura Weir G-MW manages the Weir on behalf of the Murray-Darling Basin Authority and has begun removing the weir trestles in anticipation of flows increasing over the next fortnight. Removing the trestles may see the weir pool's water levels drop by around 800 millimetres within the next few days.

"Riverboat owners and customers with pumps on the upstream side of the weir should prepare for this drop in water levels," said Mr McGrath.

Channel operations in Irrigation Areas During floods G-MW operates the gravity irrigation channel network to allow overland flows to continue along their natural course where possible.

"We shut down sections of the network that may be affected by flood waters and work with local authorities to minimise damage to the assets including the channels," said Mr McGrath.

G-MW will again be working closely with the Bureau of Meteorology and State Emergency Service as water moves through the river network.

 

For information about floods, river levels and weather warnings visit www.bom.gov.au and for emergency updates visit www.ses.vic.gov.au

 

 

-ENDS-

 

Media Contact:       Mark Kestigian

Position:                   Manager Corporate Affairs        

Telephone:               03 5833 5412 or 0419 495 092

Last updated: 22 Dec 2010