A warning to keep out of the river in the Canch park in Worksop has now been lifted.
Pollution which killed around 20 fish, including a large pike, earlier this week, has been flushed away.
Bassetlaw Council had advised people to stay away from the water until further notice.
The council has worked with the Environment Agency to test the water, identify the pollution source and open the penstock gate in the Canch to flush the water through.
Safety notices will now be taken down and the council says it is ‘business as usual’ for the weekend.
The Environment Agency has still not revealed what sort of pollution they found.
But it is understood that low oxygen levels in the water killed the fish.