Water will again flow down the Mehi River through Moree this week, following the decision by environmental water managers to re-start the river and provide flows for a fish flow event.
This will be achieved by using water from environmental accounts in the Gwydir and Border Rivers systems and is intended to provide drought refuge for fish along the systems and into the Barwon River.
Up to 37,000 megalitres is set aside to be released over the next two months from Glenlyon (in the Border Rivers catchment) and Copeton Dam (in the Gwydir).
Releases in the Gwydir began on Monday, April 15 and will vary throughout the next two months, depending on any natural inflows and stream losses.
Gwydir Valley Irrigators Association executive officer Zara Lowien said estimates predict the first flow will wet up about one kilometre of the river per day until the arrival of larger volumes of water released from Copeton Dam. However, she said it is estimated that 50 megalitres per kilometre will be lost through evaporation and seepage.
"Low flow rates will provide a gentle top-up to pools along the dry river and reduce the risk of environmental shocks that can occur when restarting a river," Ms Lowien said.
"It is hoped these flows will recharge the system through to Collarenebri, Walgett and possibly to Brewarrina. As the Brewarrina weir pool is significant it is not expected to provide flows beyond."
Ms Lowien said the Mehi River hasn't had any natural flows for more than two years, and delivering this flow is only possible because environmental water managers, like irrigators, can have carried over allocations from previous years to use now during "this unprecedented drought".
"It's expected the flows will be visible in Moree in the coming days and will be celebrated by communities right along the system," she said.
"Flow events like this are a great opportunity for everyone to see what can be achieved with judicial use of environmental water.
"While we don't know exactly how far down the system the water will reach, it's important that there has been detailed planning for the use of environmental water over different climatic scenarios for local environmental assets but also those further along the system.
"It's encouraging to see environmental water managers utilising the water management framework in the best interests of the environment by providing for flows that otherwise wouldn't have occurred.
"We've welcomed the planning and engagement of the community by environmental water managers in making this decision."
For more information about the event, see the Commonwealth Environmental Water Holder or NSW Office of Environment and Heritage, or check @gwydirvalley via Facebook or Twitter, where Gwydir Valley Irrigators Association will be providing status updates right along the river.