Relaxing constraints in the Murray–Darling Basin

The Murray–Darling Basin Authority (MDBA) has proposed a strategy to manage constraints as part of the implementation of the Basin Plan.

A constraint is any rule or structure which limits the volume or timing of the delivery of environmental water. Constraints can include physical structures, river management practices, and operational limits to river heights.

Work completed by the MDBA has shown that while easing constraints will not result in the recovery of additional water, it will allow better outcomes to be achieved through the use of environmental water. This uses environmental water more efficiently, so helps reduce the quantity of water which needs to be recovered or delivered to achieve environmental outcomes.

NSW is progressing projects in the southern Basin that manage physical constraints through supply measure projects and those that are rules based through implementation of prerequisite policy measures.

In the northern Basin NSW is considering constraints management as part of the northern Basin toolkit and consideration of implementation of active management in some northern Basin unregulated rivers to achieve better management of environmental water. More information on relaxing constraints in NSW.

Modelling of inundations in Menindee town with increased releases from Weir 32

Rain events in southern Queensland and northern NSW in late 2021 increased the volume of water flowing through the Barwon-Darling River. WaterNSW managed the volume of water held in the Menindee Lakes system by pre-releasing water at Weir 32 to accommodate these inflows.

Increasing these releases above 18,000 megalitres per day (ML/day) posed an unknown risk to properties and roads within Menindee. Manly Hydraulics Laboratory modelled and assessed the impacts of inundations of releases between 18,000 ML/day and 25,000 ML/day.

Full details are available in the Menindee Flow Release Impact Assessment.

View more information on relaxing constraints in NSW.