Authorities issue warning on residents looking at floodwaters in the south-west.

State Emergency Services divisional commander Steve McDowell said there had been some concerning behavior over the past few days.

"There seems to have been silly behaviour yesterday that is really troubling for us," he said.

"It's all about safety.

"We had reports of people hanging over the side of the bridge looking at the flood water."

That prompted the Moyne Shire Council to on Saturday close the Hopkins Falls car park.

Authorities were also concerned about the behaviour of people at the Hopkins River mouth over the weekend where dirty water is being washed out to sea.

Mr McDowell said people were seen standing on the edge of the sand where it had been eroded away.

"Our concern is if someone went in the water there is no coming back from that," he said.

"We seen some silly driving on the road. People stopping in the middle of bridges to watch the flood water is another thing we've seen."

READ MORE: Panmure bridge to close, river to peak at Allansford this afternoon

Mr McDowell said resources across the state were stretched.

He warned residents came across any road with water over it to treat it as closed even if there was no road closed sign because authorities were running low on signage.

"If there is no road closed sign there, don't think the road's open," he said.

"Any water over the road, treat it as a road closed."

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