Southern Spring flow 2019 - Update #6 - 12 November 2019

2019

Commonwealth Environmental Water Office

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Southern Spring flow 2019 - Update #6 - 12 November 2019 (PDF 599.8KB)

The Southern Spring Flow is nearly complete!

Objectives	Provide food and shelter for native fish and other animals along the River Murray, from Hume Dam to the Coorong.
Start date	1 August 2019 (Hume Dam release)
End date	Flows downstream of Yarrawonga in the mid-Murray finished on 19 October. The tail end of the flow is expected to reach the Lower Lakes and Coorong mid to late November.
Volume	Approximately 330 gigalitres
Target sites	River Murray channel and key wetlands and creeks in Barmah-Millewa and Gunbower-Koondrook-Pericoota forests, Edward-Wakool, Lake Kramen (Hattah-Kulkyne Lakes), wetlands in Chowilla, Coorong and Lower Lakes.

Swamp Harrier, Barmah Forest. Photo: Keith Ward and Tim Barlow, Goulburn-Broken CMA.

While the taps for the Southern Spring Flow have been turned off, the flows are continuing their journey down the River Murray to the Lower Lakes, Coorong and Murray Mouth.

Wetland plants growing following the flows at Steamer Plain. Photo: Keith Ward and Tim Barlow, GBCMA.

Forest regulators on the Barmah (Victorian) side of the River Murray closed on 31 October. This will avoid triggering large-scale waterbird breeding which would fail under the drought conditions. It will also avoid the spread of giant bull rush which is reducing the amount of valuable open-grassy wetland.

Deb Furst (University of Adelaide) processing Lower Murray River zooplankton samples.

Regulators on the Millewa (NSW) side will remain open until the end of November to allow Murray Cod to finish breeding and move out of forest creeks. Environmental water holders cover the cost of any additional water use in the forest from leaving regulators open.

Water delivery to Lake Kramen at the Hattah Lakes complex is now also complete.

Many hands make right flows

Coordinating environmental flows across multiple states requires the efforts and careful planning of many organisations. The Southern Connected Basin Environmental Watering Committee coordinates the delivery of environmental flows in the Southern Murray-Darling Basin.

The Southern Spring Flow was made up of water from the Commonwealth, Victorian, NSW and South Australian governments. Much of this water had been deliberately carried over from 2018–19 in expectation of continuing dry conditions.

Decision making for the flow was underpinned by science and based on lessons learnt from previous years and advice from local land and water managers.

Measuring success

Even in dry times like now, before dams, weirs and water extraction, natural inflows would have improved water quality and replenished the River Murray.

The flows have been critical to keeping the river healthy for all users and providing much needed food for native fish and wildlife.

The flows aimed to provide food and shelter for native fish and animals along the entire length of the river. We have tracked the flow as it travels down the river and are working with communities and experts to closely monitor the environmental benefits.

Plankton and water quality monitoring is running smoothly, with over half of the planned sampling trips now complete. Fieldwork will continue into December. Processing of the field samples taken is underway in laboratories, and results are expected to be finalised and published in a report during early 2020.

Footprints in the forest

Environmental water managers are using satellite imagery to better understand how and where water flows, particularly in remote locations.

The images on the next page show the Southern Spring Flow only inundated just a fraction (around 25 per cent) of the Barmah-Millewa Forest, compared to the larger inundation from natural flooding in 2016. The blue-shading in the images represents the ‘water footprint’ for each year.

More information: The Southern Spring Flow 2019