Darling-Barka flood recovery program

This program will monitor river health until June 2025 and is coordinated by the EPA.

About the program

A comprehensive river health monitoring program that extends the NSW Government’s incident response to the floods and fish kill disasters that occurred in early 2023.

The program will run until June 2025 and is jointly funded by the Commonwealth and NSW governments through the Disaster Recovery Funding Arrangements.


The floods and fish kill that occurred in the region in early 2023 were disaster events. Through the NSW emergency management arrangements, the NSW EPA responded as the lead agency for environmental services for the disasters.

We worked closely with the Science Division of the Department of Planning and Environment (DPE Science) to sample the Darling-Barka River from 21 March 2023. Sampling is ongoing and results are available.

We have listened to community concerns about the health of the Darling-Barka following the disasters and are committed to understanding the longer-term effects of those events on the ecological and cultural values and overall health of the river. The EPA Recovery Program will monitor river health over two years.

The program is separate to existing regulation by Water NSW and is independent of the EPA’s investigation into the possible causes of the March 2023 fish kill event under the Protection of the Environment Operations Act 1997.

How the program works

The program is coordinated by the EPA as the lead agency for the NSW Environmental Services Functional Area. It will be delivered until June 2025, extending on the incident response sampling already undertaken this year.

The program involves the delivery of 2 key projects:

  • An Aboriginal Knowledge Project to be designed with local Aboriginal groups and knowledge holders to ensure it supports healing Country for those who care for Country.
  • DPE Science River Health Project which will deliver ecological monitoring of a range of river health indicators, assessment of results by experts, agencies and the community, and sharing data to inform future research and water management of the system.

Results so far

There is a wealth of water quality information and the existing regulation of the Darling-Barka that can be found on the Water NSW website, including community updates.

Results from our incident response sampling since March 2023 show similar results to those provided by Water NSW in this period. They suggest:

  • Fish populations in the area had boomed post flood.
  • At the time of the fish kills, water samples indicated that the river was experiencing a hypoxic event where dissolved oxygen is stripped from the water. This is common after floods.
  • Both these factors – increased fish populations in low-oxygen, post flood waters - appear to be the cause of the event in March 2023.
  • Results have not found any indication that pesticides or heavy metals were present in the water or within dead fish.
  • More time is needed to generate a clearer picture of river health in the Darling-Barka as it continues to recover and we head towards a potentially dry summer season.