Lake Mulwala will be lowered by about 3.5 metres this winter to facilitate works around the lake foreshore and weed control.
Murray–Darling Basin Authority (MDBA) head of River Management, Andrew Reynolds, said locals and visitors to Lake Mulwala and Yarrawonga Weir might notice changes to water levels from the end of April.
"We're undertaking this work in conjunction with Goulburn-Murray Water (GMW) to improve infrastructure at the lake and to control invasive aquatic weed—we plan to have the lake back to its usual level in early August," Mr Reynolds said.
"Lake levels will start to fall slowly from 30 April by about 70cm until mid-May when the irrigation season ends.
"Once we are sure that irrigation water delivery to customers is finished for the year, we'll accelerate the drawdown until Lake Mulwala is 3.5 metres lower than normal—a level we expect to hold until mid-July when refilling will start.
"The drawdown will be managed in a way that poses minimal risk of impacting on available water resources in the coming season.
"I recognise that Lake Mulwala is important to the local community and that any significant change in the lake level may have social and economic effects," Mr Reynolds said.
"The lowering will expose the lake flats, which will be muddy, reducing amenity, access and the ability to launch boats from the boat ramps. People will still be able to boat and fish in the main river channel that runs through the lake but will need to launch their boats upstream.
"Along with GMW we have been talking with community members, council and tourism operators to try to minimise and limit disruptions."
GMW General Manager Customer Operations, Scott Barber, said that winter draw-down was important because it enabled structural works to be undertaken around the lake.
"We'll use this opportunity to upgrade the retaining wall along the Yarrawonga foreshore and look to assess and improve boat ramps if needed," Mr Barber said.
"The main reason for the winter draw-down is to control the extensive build-up of the highly invasive aquatic weed Egeria densa which can displace native submersed vegetation and impacts on the lakes' usage, making it harder to swim, fish, launch boats and water ski.
"We have listened and taken on-board community feedback about the build-up of the aquatic weed in the lake and suggestions of a drawdown this year to reduce the weeds impact on recreational activities.
"Previous winter draw-downs have proved effective in controlling the waterweed which dies off as it dries out and when exposed to frost."
Last year GMW and the MDBA released the Waterweed Wipeout app. The tool is designed to help the community better understand the management techniques used to control the invasive weed. Waterweed Wipeout is free and available from the App Store and Google Play for Apple and Android phones and tablet devices.
In accordance with the longstanding Murray–Darling Basin Agreement, River Murray operations assets are owned by a 'Joint Venture' comprising of basin state and federal governments. The MDBA is tasked to operate the River Murray system on behalf of the Joint Venture. GMW is the state constructing authority responsible for managing and maintaining Lake Mulwala under the direction of the MDBA.
ENDS
For more information, contact the MDBA Media office at media@mdba.gov.au or
02 6279 0141 or Richard Bryce at GMW on (03) 5826 3470.
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