Council placed signs along the Wimmera River on Thursday which indicated fishing, swimming and drinking were banned and animals and vessels were not permitted in the water because `harmful algae may be present'.

Major recreational water Taylors Lake near Horsham is also hit by blue-green algae.

Hindmarsh Shire Council infrastructure services director Andrew Bainbridge said the Wimmera River was not officially closed but people or animals who made contact with the water did so at their own risk.

Mr Bainbridge said GWMWater tested the river water on January 21 which later confirmed the presence of blue- green algae.

He said results took several working days to arrive but the Australia Day public holiday delayed the process and council was unaware of the algal bloom until Thursday.

"At the very least we needed to alert the community of the presence of blue-green algae by placing the signs," he said.

"Blue-green algae blooms very quickly and it can recede just as quickly, so given it takes a couple of days to get test results, the water could have already returned to a safe level."

The discovery of blue-green algae in the Wimmera River has also revealed wide-scale confusion over where responsibility lies regarding algae management in the Wimmera River.

Mr Bainbridge said council had sought assistance and advice from GWMWater and Wimmera Catchment Management Authority regarding the bloom but neither had claimed responsibility for the issue.

"Council's primary concern is for public health and safety. We don't want to leave the signs up longer than necessary so we are extremely keen to establish who exactly should be looking after this matter," he said.

GWMWater corporate services manager Andrew Rose said the matter was not GWMWater's responsibility and advised the Mail- Times to call Wimmera CMA.