Dungog a 'horrendous mess' in NSW storms

A man who escaped Dungog through a back route says the NSW country town is a mess as homes, animals and railway lines are washed away in a savage storm that has claimed three lives.

David, who didn't give his last name, says families have been left empty-handed without even their wallets as flooding and wind pounded the Hunter region town on Tuesday.

Animals have been floating in the streets, people have been swimming onto their roofs and a timber mill has been destroyed, David told ABC Radio after he checked on his wife's family in town.

"People don't understand, Dungog has been smashed," he said on Tuesday evening.

"The town is a mess.

"People have got nothing...it's just been horrendous."

A woman and two men, all believed to be elderly, died in their homes as water surged through the town after more than 300mm of rain fell in 24 hours.

David said he got out of the town using a back road because access on the normal routes had been blocked by weather conditions.

The State Emergency Service told AAP they have been assembling crews to go in once they can access the area.