THE banks of the Peel River in the middle of Tamworth could be the scene of the state's next fish kill without serious inflows.
Water experts and state government officials have warned dams and rivers across the New England and North West would be susceptible to blue-green algal outbreaks come summer, if the current conditions continue.
"[Governments] hold grave concerns for communities and rivers across the northern basin which remain under considerable stress because of the drought," a Murray-Darling Basin Authority spokeswoman said.
"Fish remain extremely vulnerable in the north and will remain so until significant inflows are received."
OzFish North West president Anne Michie said there could be a fish kill in the middle of Tamworth once the Peel River is blocked by two soil weirs - one near Dungowan village, the other at the Jewry Street bridges - creating the "perfect storm" for an algae bloom.
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"The weirs will create a big pool of stagnant water right in the middle of town, and you've got a colony of flying foxes along the river, dropping nutrients in to the water," Ms Michie said.
"The moment we get some hot weather, it will be ripe for blue-green algae."
Last week, there were reports of large Murray cod washed up on the shores of Chaffey Dam, and Ms Michie said "sadly, it's going to get worse before it gets better".
"The loss of these great fisheries in our northern basin aren't just emotionally and environmentally significant, they are a big loss to our economy," she said.
"Angling is a billion-dollar industry for inland NSW. A lot of small businesses get hurt, and it's not just the tackle shop, it's the servo selling fuel to people on boats, it's the corner shop where people get their bag of ice. There are less people camping and travelling."
Water NSW said it was working closely with other agencies to determine the best times to do small periodic releases where possible, to avoid adverse environmental events such as the Menindee fish kill earlier this year.
Agriculture Minister Adam Marshall said the government was working on ways to reduce the impact of fish kills.