Review of Murrumbidgee environmental water releases - 2016/17 and 2017/18

Large-scale environmental watering trials were conducted in 2016 and 2017 to deliver environmental water along the length of the Murrumbidgee River system.

The ‘native fish’ event’ (2016/17) extended the recession of flows in the Murrumbidgee River following natural flooding during the winter and spring of 2016. This event provided beneficial flows for native fish and diluted de-oxygenated water returning from the floodplains in the lower Murrumbidgee and Murray Rivers. 371 GL of environmental water was delivered, including 236 GL of held environmental water (85 GL of The Living Murray entitlements and 151 GL of Commonwealth account water).

The ‘wetlands reconnection’ event (2017/18) was a stand-alone winter release of environmental water to provide beneficial flows for low-lying floodplain areas. Releases from storage were made during a period where there were no significant prior river flows, and only modest downstream tributary inflows were occurring. Flow targets were at Wagga Wagga, downstream of Gogeldrie Weir and downstream of Maude Weir.

These two environmental water releases were conducted prior to implementation of the pre-requisite policy measures. As part of these events, NSW used a ‘Bulk Entitlement Delivery’ mechanism which relied on Clause 98 (MDBA’s Role in the Operation of Storages) of the Murray-Darling Basin Agreement. Clause 98 allows NSW to direct the MDBA (as the river operator)to make an operational release of environmental water to flow the entire length of the River Murray System, including downstream of Lake Victoria. NSW formally notified the MDBA that a portion of the flows from the Murrumbidgee valley should be recognised as environmental water in the River Murray and delivered to the South Australian border as a “bulk delivery” of NSW water.

The processes and procedures used during these two environmental water events have been documented and reviewed to inform both future environmental water deliveries and the development of Prerequisite Policy Measures (PPMs) in NSW. The Review of NSW Murrumbidgee Environmental Water Releases report (PDF, 1743.56 KB) provides an overview of each event, as well as:

  • a summary of the operational implementation of the event,
  • accounting provisions, and
  • protection of environmental flows.