Winter environmental flow good for fish food and bank plants

Water bugs and plants that provide food and shelter for native fish and other aquatic animals will benefit from an environmental flow along the lower Goulburn River planned for mid-June.
Wednesday 24 May, 2017

“As much of the rain and run-off into the Goulburn River is now captured in the dams and used to supply towns, industry and farms, the amount of water flowing down the river in winter and spring has reduced,” Goulburn Broken CMA Environmental Water Manager Simon Casanelia said.


“It also means the river flows higher and faster in the hotter months of the year when communities require more water, which is the opposite of what would happen if there were no dams and weirs.


“These changes have affected the health and survival of native plants and animals, so we’re giving nature a helping hand and delivering environmental water at this time of the year to mimic more natural flow conditions.”


Water for the increased flow is due to be released from Goulburn Weir from June 20, peaking at about 9,500 ML/day (4.30m) at Murchison on June 30.
The increase in river flow and height is well below minor flood level (9m at Murchison and 9.5m at Shepparton). In the event of heavy rain, the timing and size of the environmental flow could change or not go ahead at all.


The graph below shows how the river height and flows will change during this period:


 
 Mr Casanelia said the environmental flow would also help bank-stabilising plant growth on the lower banks of the lower Goulburn River.
“Recent monitoring shows that the river banks held up fairly well during the natural floods we experienced late last year. This was due to the ‘right’ types of native plants starting to establish and spread thanks to environmental flows delivered during the past few years.


The extra water will also improve water quality and provide food and shelter for waterbugs and native fish.


 “Improved water quality will help crayfish, shrimps, water bugs and native fish continue to recover after the naturally occurring blackwater event that occurred earlier this year after a summer storm.”


Environmental flows are planned by the Goulburn Broken CMA in consultation with the Commonwealth Environmental Water Office and managed by Goulburn-Murray Water in line with the Victorian Environmental Water Holder’s Seasonal Watering Plan 2016-17. Timing of the environmental flows take into consideration delivery orders by irrigators and other water users and feedback from the community via the Goulburn Broken CMA’s environmental water advisory groups.
 
Environmental watering is only one way of protecting and improving rivers and wetlands. Fencing and revegetation, erosion control, pest control, returning logs to rivers for fish and bug habitat, and installation of fishways to allow fish to pass through dams and weirs also help. Find out more about these activities at www.gbcma.vic.gov.au