Goulburn Valley Environment Group is concerned the health of the Goulburn River is continuing to decline, arguing high summer flows were causing damage and undermining improvements gained by recent years’ environmental flows.
One local fishing figure said if the ‘‘anatomy of the river’’ was compromised, the flow-on effect could see recreational use of the river undermined.
Goulburn-Murray Water river operations manager Andrew Shields said a flow of 8500Ml/day was being released from Lake Eildon from January 11 to meet irrigation demand within Goulburn irrigation areas, to maintain Waranga Basin’s required operational levels and for inter-valley trade water delivery from the Goulburn system to the Murray system.
‘‘There is a flow of 3000Ml/day being released from Goulburn Weir to the Goulburn River to deliver inter-valley trade water to the Murray system,’’ he said.
‘‘Delivery of inter-valley trade water will continue to occur for the coming months, with the rate expected to be maintained around 2800 to 3000Ml/day for the coming weeks.’’
Dry conditions and high demand early in the irrigation season have seen transfers from Lake Eildon to Waranga Basin, with inflows to Goulburn system storages well below the long-term average over the past 12 months.
Goulburn Broken Catchment Management Authority said flows were expected to range between 2000Ml/day to 3000Ml/day over the next few months.
The flows, which are above the recommended 800Ml/day for this time of year, have prompted Goulburn Broken CMA to ask river operators to deliver water as a series of pulses through the lower Goulburn River, rather than a steady flow, to help minimise damage to the river bank.
Goulburn Broken CMA said the high unseasonal flows in the lower Goulburn River continued to be delivered to meet downstream water demands from towns, irrigators and the environment.
GVEG has suggested a number of urgent actions, including implementing a maximum seasonal volume for flows through the Goulburn River, to combat the potential effect on river health and water quality.
‘‘The end result, if we let this grow and continue ... we’ll lose that in-stream health, aquatic recreation will be affected,’’ GVEG president John Pettigrew said.
He welcomed recent pulsing of water as being part of the answer.
Shepparton fishing industry stakeholder Steve Threlfall said unseasonal high flows down the Goulburn that were prolonged for more than three weeks posed the most concern for river banks and habitat.
‘‘That constant water flow has an effect on our vegetation,’’ Mr Threlfall said.
‘‘That bit just above the water ... (it’s) now constantly at higher levels ... for long periods and it’s killing it off.’’
Goulburn Broken CMA said it was working with DELWP to understand and quantify potential environmental impacts of unseasonal river flows due to water trading, including additional monitoring this summer.
—Thomas Moir and Alana Christensen