Millions of dead fish washed up in the Darling-Baaka River at Menindee earlier this year, with Premier Chris Minns and Environment Minister Penny Sharpe visiting the region in the days after the NSW election.
Water testing will be carried out in the Darling-Barka River by the NSW EPA this week, and the authority is committed to sharing its results with advocates and locals, the NSW government said on Saturday.
Menindee residents have been concerned about the quality of their drinking water since the event, with some having treated water trucked in by the local council.
The government says steps are also being taken to prevent future fish kills in the river, as the system remains stressed and fish species compete for depleted food resources in the cooler months.
Earlier this week, the EPA said the fish kill would be treated as a pollution incident as it investigates the cause.
The fish deaths were blamed on lowered levels of oxygen in the river, known as hypoxic black water, which was worsened by flooding and unseasonal heatwaves.
EPA testing has so far ruled out pesticide pollution, but revealed the area contained potentially toxic algae and blue-green algae.
Oxygen levels in the waters at Menindee are now healthy, but agencies are working to stabilise the river in case of a change in conditions.
This includes maintaining flows to keep waters oxygenated, and engaging a commercial fisher to hunt invasive carp, which pose a threat to native bony herring fish.
Advice on water quality will be shared with the Menindee community as it becomes available, so locals can understand the way changing conditions affect drinking water quality, and how water can be used for agriculture and recreation, Water Minister Rose Jackson said.
"We're taking steps to ensure the community can have confidence in the management of Menindee for its protection and for future generations," Ms Jackson said.
The EPA's water sampling will also be used as an early indicator tool, signalling to the government when further interventions may be needed, Environment Minister Penny Sharpe said.
"These results are being shared with the community as soon as possible, while the EPA continues its own investigation."
