Annual environmental water priorities in the Macquarie valley

Maintenance of core assets and protection of ecosystems against drought are the focus of water for the environment in the Macquarie valley in the year ahead.

Priorities for 2017–18

Climate models are indicating a neutral El Nino-Southern Oscillation for the second half of 2017 with warmer and drier than average conditions expected in winter across Australia.

As a result of recent floods, a reasonable volume of licensed water is available for environmental watering events.

Water managers have prepared watering plans that take into consideration a range of weather and water availability scenarios, in case it rains more or less than expected. This is known as ‘Resource Availability Scenario’ planning. Under a very wet scenario a range of actions are proposed for the Macquarie–Castlereagh Water Resource Plan Area that respond to the wetter conditions.

Further details on watering priorities for 2017–18 can be found in the Statement of annual environmental watering priorities 2017–18 (PDF 800KB).

Highlights from 2016–17

Bankful and overbank flows, fledged waterbirds with low mortality rates, native fish movement

Environmental water manager Tim Hosking said 2016–17 was a significant year for the Macquarie catchment in a number of ways.

'Following big rains in mid-2016, we saw bankful and overbank flows in various parts of the Macquarie catchment. These connected many streams within the catchment and provided a strong connection to the Barwon River downstream,' Mr Hosking said.

‘With Burrendong Dam spilling in September 2016, all the water users found their accounts full which allowed us to respond to the wet conditions. Monitoring of colonial waterbird breeding in the Marshes indicated the ibis colonies would be finished by Christmas, but large egret and heron colonies would need water well into February.

'We targeted managed environmental flows to follow the completion of the Burrendong dam spill water to ensure the egret and heron colonies achieved fledged young. Monitoring indicated that we reached most of the colony sites and that the Marshes colonies had a low mortality rate.

‘In Autumn 2017 we capitalised on tributary flows into the Macquarie River along with Barwon River flows from Cyclone Debbie to connect within the Macquarie and also to the Barwon River. These flows were targeted at helping native fish species including golden perch (yellow belly) and a range of smaller species like hardyhead and spangled perch.

'The DPI-Fisheries fish monitoring program in the catchment indicated that fish used these flows to move, including the first ever record of the Hyrtl’s tandan (Hyrtl’s catfish, Yellow-finned catfish), in the lower Macquarie River near Carinda.

‘As with all environmental flows, these flows all had other linked benefits, including inundating parts of the Macquarie Marshes and supporting the health of the mid-Macquarie River upstream of the Marshes.

‘This wet year will allow us to plan a few years in advance by using our carry-over over time,' Mr Hosking said.