Hundreds of fish have died near Wellington due the recent storm activity that resulted in the water quality deteriorating.
Wellington fisherman and president of the Twin Rivers Fishing Club, Norm Wilson attended the scenes with Department of Primary Industries Fisheries experts on Wednesday.
Close to 300 dead carp and some native fish were pulled out of the bottom end of the Bell River.
Other fish impacted included Murray Cod, Golden Perch and Freshwater Catfish, as well as carp and shrimp.
"The Bell River waters have then hit the Macquarie so there's been a few sightings of fish kills from where the Bell River junctions into the Macquarie down into towards Ponto Falls," Mr Wilson said.
"So that whole section of river has been affected."
The deaths are the result of a combination of things, the Wellington fishing club president said.
"All the dirty water, all the sediment that's been dragged off the hills with the flash storms we've had de-oxygenated the water and it seems to be what has been knocking the fish over," Mr Wilson explained.
"We're on the back end of a pretty severe drought so there's no real grass cover on any of the paddocks so that sort of acts as a filter. So when we get a heavy downpour if there's no grass that filter network just gets lost.
"All of that sedimentation and whatnot ends up in the river. Copping it all at once the fish just can't cope with it."
A DPI Fisheries spokesperson said the Bell and Macquarie rivers continue to be put under extreme stress as a result of the ongoing drought.
"However, there was much welcomed rain in the region, which has caused localised short, sharp flow in reaches of the Bell and Macquarie rivers," the spokesperson added
"Short-term impacts on water quality are expected when flows resume within drying rivers, including rapid reduction in dissolved oxygen levels that results from the washing in of organic matter and sediment that has built up during the extended drought. This can have localised impacts on native fish species."
The water quality started deteriorating on Sunday and as oxygen levels in the river decreased the fish couldn't cope.
"It would be like us trying to breathe with a plastic bag over our heads. There's just no oxygen in the water," Mr Wilson explained.
ALSO MAKING NEWS: See all the photos that show the dust storm blanketing the region
DPI Fisheries staff have been in the field investigating the event, confirming the kill and undertaking water sampling, which showed at risk levels of dissolved oxygen for native fish along reaches of the Bell and Macquarie rivers.
Mr Wilson said approximately 15 kilometres of the Bell River is affected, with a similar affected area on the Macquarie from the Bell River junction down to Ponto.
The Wellington fisherman said it was sad to see the dead fish, especially being a part of the Club that is dedicated to improving local waterways.
Earlier this week thousands of fish were killed near Dubbo by the same storm activity that has resulted in the most recent fish deaths at Wellington.
The affected water at Wellington is heading downstream towards Dubbo.
Mr Wilson said it was hard to say whether these fish deaths will continue and is hopeful that the majority of the sediment is gone.
"We might get a bit of cover to slow the water down after these last lots of rain, but it's one of those Mother Nature, great unknown things," he said.
"You'd like to think this is an isolated event, there's a number of things that have contributed to it over time...."
If you have noticed any fish kills please contact the Fishers Watch hotline on 1800 043 536.