3870 megalitres released from Chaffey Dam with peaks of 750 megalitres a day

Dam drop: The environmental water release will see Chaffey Dam drop by three percent in order to improve fish habitats. Photo: Peter Hardin
Dam drop: The environmental water release will see Chaffey Dam drop by three percent in order to improve fish habitats. Photo: Peter Hardin

The Peel River is being flushed with extra water following an environmental release that will see Chaffey Dam water stocks drop by around three percent to improve fish habitats.

The unique morning glory spillway was opened last Tuesday, according to a Water NSW spokesperson, who said the dam would continue to release water until June 18, when all 3870 megalitres (ML) would have been released.

While the original plan of releasing all 6357 ML in the lease was reduced following an outcry from local stakeholders, including both state and federal representatives, the smaller volume was released with a higher peak of 750 ML per day in order to “wet more instream habitat.”

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To put that into perspective one Olympic swimming pool holds approximately one megalitre of water, and one millimetre of rain falling on one square kilometre is also one megalitre.

Early last week flows were measured at just 56 ML a day in Tamworth, before the release hit on Saturday with 773 ML surging over the Jewry Street weir. On Tuesday that flow had reduced back to 319 ML.

“We want it to mirror the natural operation of a river system as closely as possible, so the flow peaked on June 7 and 8 with 750 ML a day, but it is tailing off now,” the spokesperson said.

“It is important to note that this water order, placed by the NSW and Commonwealth governments, is owned by these government environmental entitlement holders, which can utilise the water at its discretion as is the case with any other legitimate customer.”

The water was released under an order from the NSW office of Environment and Heritage (OEH) “to meet the specific objective of providing additional habitat for fish to access food resources and move through the river system.”

A spokesperson for OEH said that the decision to release the water was made in conjunction with the Commonwealth Environmental Water Office and the Department of Primary Industries.

This time last year the full volume of 6357 ML was released for the same reason.

“This year, we are using a lower volume in total, but a higher peak of 750 ML per day to wet more instream habitat to improve upon environmental outcomes measured last year,” the OEH spokesperson said.

“Wetting a greater proportion of habitat will provide a better influx of food for fish.”