WaterNSW moves to secure critical water needs on Macquarie

Macquarie River water crisis. Photos by Rachael Webb.
Macquarie River water crisis. Photos by Rachael Webb.

Regulated river flows on the Macquarie River will cease beyond Warren in just four months as WaterNSW acts to secure water for critical needs along the river.

Dubbo Regional Council was in talks with WaterNSW officials today to talk about looming water supply issues as Burrendong Dam slowly drains. Burrendong is unlikely to be able to release water by gravity from March next year and run dry by July next year unless there is solid rain.

WaterNSW warned: that "without inflows high security customers including the Cobar mines, Dubbo abattoirs, permanent plantings, Western Plains Zoo and Dubbo golf club are at risk of having reduced access to water after July".

It said that "already no allocation for general security in 2018-19 and 30 per cent of irrigation carryover and environmental water is withheld pending further inflows. No general security irrigation allocation will be available in 2019-20 if conditions remain dry."

It said it had begun investigations "to secure water supply for critical needs".

In a statement it said: "Under current conditions regulated river flows beyond Warren will cease from early spring 2019 to conserve water for town water supply and high security users.

"Temporary modifications to Warren weir and the regulators at Duck and Crooked Creeks will be required to raise the weir pools to permit water to be supplied to Nyngan and Cobar.

"These changes will be temporary and reversible to enable flows from rainfall events to be directed to downstream customers when possible.

"The preliminary Warren weir works commenced last Thursday (May 9) and come as Burrendong Dam reaches 6.2% of storage capacity and record drought conditions in the valley cut inflows to unprecedented lows.

"Even with a further water transfer from Windamere Dam (33.2%) via the Cudgegong River, and pumping water from below the dam outlets, Burrendong could run dry before June 2020 without significant rainfall."

There will be a meeting of key stakeholders on the new Macquarie River Operations Stakeholder Consultation Committee in Narromine on 16 May. WaterNSW was updating Dubbo Regional Council today.

"Landholders' access to water for stock and domestic use will depend on dam inflows and tributary flows and are likely to be only intermittent from July, especially downstream of Warren," WaterNSW said.

"Burrendong dam is likely to be unable to release water by gravity by March 2020 at which point WaterNSW would be required to pump the remaining water from the storage to continue to supply water to towns downstream. Even with all these measures the system could cease to flow by June 2020 if there are no inflows to the system.

"March Inflows from tributaries between Burrendong Dam and Warren have been directed into the Lower Bogan River, Marra Creek and Lower Macquarie River for critical human needs."

WaterNSW executive manager for system operations, Adrian Langdon said the Macquarie valley is in the grip of one of the worst droughts on record.

"With ongoing low inflows and storage levels continuing to decrease, the Macquarie Valley is a priority catchment for drought response and WaterNSW is working hard to extend the supply of water to regional towns for as long as possible.

"We are looking at a range of options including temporary modifications to the Warren weir and our regulators at Duck Creek and Crooked Creek.

"These temporary works would help us to minimise any system losses and extend existing limited water supplies for Warren, Nyngan and Cobar," he said.

Burrendong Dam.

Burrendong Dam.

WaterNSW said it was working closely with state and federal government agencies to ensure the options meet the critical water needs of regional towns and that the social, environmental and economic impacts are being monitored and effectively managed.

"Across the state, WaterNSW's management of the storages and river system has delayed the worst effects of the drought," Mr Langdon explained.

"If not for the efficient storage of the 2016 flood inflows in our northern dams, many of these river systems would have ceased to flow a long time ago."