Wimmera Catchment Management Authority, Parks Victoria, Department of Sustainability and Environment, GWMWater, Hindmarsh Shire and Horsham Rural City council representatives discussed the issue after a blue-green algae outbreak at Dimboola.

GWMWater service delivery executive manager Stephen Jewell said the review would determine if the nominated water managers were the most appropriate authorities for managing algae.

He said the review would also bring the co-ordination plan, created in 2008, up to date with the latest DSE guidelines for algae management.

Mr Jewell said the plan contained agreements made as far back as 1995 which had been `lost in the sands of time'.

"It was then Wimmera- Mallee Water agreed to decommission the Dimboola weir as it was no longer needed for water supply," he said.

"The shire wanted to keep it for social and amenity reasons so the responsibility for maintenance was transferred to the shire. Council has since carried out weir maintenance and GWMWater has not been involved since that time but formal agreements have long been forgotten."

Hindmarsh Shire Council chief executive Dean Miller said there was still `some uncertainty' as to whether council agreed to become a local water manager for the Dimboola weir pool and if it had, whether the agreement remained valid after shire amalgamation.

He said council staff looked forward to viewing the redrafted regional co-ordination plan and in the interim would work with GWMWater to manage the algae outbreak at Dimboola in the interests of public safety.

"We have to ask was the appointment made properly? Has council agreed to the regional co-ordination plan? And if it has, how was that decision made?" he said.

"Agreements can't be made unless they are put in writing or follow proper processes. It is important responsibilities are properly documented from this point on so we don't end up in a situation like this again."

Mr Jewell said GWMWater would distribute copies of the revised regional co-ordination plan to water managers across the region for feedback and comment. He said GWMWater would review incident management plans for future blue- green algae outbreaks at an annual meeting in late October or early November.