Big bang for water buck
A series of co-ordinated flows in north central Victorian waterways in October will provide clear benefits to irrigators, rivers, native fish and nearby communities.
Water will flow down the Loddon River, the Little Murray and Box Creek at a volume and time designed to benefit native fish.
The flows are part of the North Central Catchment Management Authority’s (CMA) Native Fish Recovery Plan, which aims to rebuild fish numbers in the region’s waterways.
More than a century of regulation, and the introduction of pests such as carp, have seen fish numbers dramatically decline, with only 13 of the pre-regulation 22 fish species surviving.
“Naturally, fish know that when food is available and safe breeding grounds are in the rivers, floodplains and wetlands, it’s time for them to breed,” North Central Catchment Management Authority Program Delivery Executive Manager Tim Shanahan said.
“Water regulation and clearing of a lot of our waterways has seen vital snags and deep holes disappear while flows no longer reflect natural conditions.
“By managing the right amount of water at the right time and continuing our snagging, fencing and revegetation programs, we can give these fish more of what they need.
“Recreational fishing is worth about $500 million to north west Victoria annually, and employs about 2000 people, so flows such as this are vital for local communities and economies, in the medium and long term.”
The North Central CMA is working with Goulburn-Murray Water and the Victorian Environmental Water Holder to time water volumes to meet at the Kerang Weir and increase flows to the lower Loddon River into the Murray River.
“This will encourage fish to move from the Murray into the Loddon and also up through Pyramid Creek up to Kow Swamp, where there is plenty for them to eat and safe places to breed,” Mr Shanahan said.
“There is a lot of demand for water and the great thing about this flow is that it will all end up as water for irrigation as it travels down the Murray.
“On the way it will benefit native fish in the Loddon and the river itself. Everyone, and everything, gets a really good bang for their buck out of this flow.”
A similar flow last year had impressive results.
“We know that golden perch are on the move at the moment, so the timing is perfect,” Mr Shanahan said.
“Last year the Arthur Rylah Institute, through the Victorian Environmental Flows Monitoring and Assessment Program, recorded significant fish movement of both golden perch and the Critically Endangered silver perch in the lower Loddon system during the flow.
“Only four native fish species were found before the flow last year, and seven during, which shows fish were moving about. And the numbers of fish moving through the Loddon chute near Canary Island, and at the Kerang Weir, increased substantially.
Another flow will go down Serpentine Creek and Nine Mile Creek to improve conditions for platypuses and water rats, as well as local river blackfish.
That flow will also help water a small redgum woodland along the waterway, for the first time.
In total, about 7600 megalitres of water will flow down the waterways.
The flows are part of the Victorian Government’s $222 million investment over the next four years to improve the health of waterways and catchments, and are authorised by VEWH in line with its Seasonal Watering Plan 2018-19.
The VEWH Seasonal Watering Plan 2018-19 is available for download from www.vewh.vic.gov.au, with regular watering updates posted on the North Central CMA website