Charles Sturt University Adjunct Professor Max Finlayson, an expert in water and land management, is appealing to local government areas to make safeguarding waterways a priority ahead of the next major rainfall event.

"When we get a lot of rain, and it is a when and not an if, there will be carry-off of ash, sediment and nutrient slugs that will flow straight into our waterways, potentially making them undrinkable," Professor Finlayson said.

The absence of adequate land covering in the wake of the fires, Professor Finlayson believes, sets the precedent for unstable and dead vegetation to be carried into the river systems.

"It's a problem for biodiversity, this fine particular matter could mean we'll be facing a big season of fish kills," he said.

"It also has the effect of [promoting] algae blooms, which is not only toxic to the creatures living in the waters, it affects humans too."

Professor Finlayson said it could be a 'perfect storm' of adverse situations that conspire together to make for the worst outcome.

"High temperatures, low water levels, sudden rainfall, a plug of particles and we're facing a problem particularly with algae," he said.

On a small scale, the situation has been of concern to the residents of Oberne Creek, south of Tarcutta.

With a vast amount of their landscape affected by the fires, recent rainfall of up to 20mm resulted in ash-filled creeks and blocked dams.

"It could happen anywhere there's been a lot of burnt areas and a sudden amount of rain," Professor Finlayson said.

"I don't want to appear doom and gloom, but we're already having this happen. There are already reports of storms causing these sorts of run-off."

Acknowledging the need to prioritise other needs as the fires continue to burn across the state, Professor Finlayson said this year's disasters could prove a springboard towards future-proofing the nation's fire response.

"We can't control the rain or where it falls, but there are things that we could do in the longer term to plan for the future," he said.

"At a local level, it could be something as simple as putting in straw bails to slow the debris from flowing straight into the waterways."

To safeguard the biodiversity, Professor Finlayson recommends engaging wildlife conservation strategies including removing small populations to keep control groups of healthy species.

"The Murray Darling River fish kills last year got us thinking, how can we preserve our fish species as a last resort," he said.

"Most things need water, we know that, and not having access to water might put things, like wallabies under threat.

"We don't really know what contamination level these animals can tolerate. We just know they need water and the higher the quality, the better for their health."