About 35 people attended the council's presentation on the issue in Ranfurly yesterday.
Regional council senior environmental officer Kevin Allan said Bennett's wallabies were potentially an ''enormous problem'' for the area.
''If these wallabies are allowed to establish, they're going to devastate our environment potentially, or certainly change the environment in a significant way.''
The number of reported incidents in Otago ''substantially'' increased in early 2016, although this was partly due to increased awareness, he said.
''We can safely say we have wallabies in Otago.''
Sighting areas included the North Otago region, Dansey's Pass, Kakanui, Kyeburn, Maniototo, and the Lindis Pass.
It was hard to know the movement patterns when a small number of wallabies entered a new area, Mr Allan said.
He emphasised the importance of reporting any sightings of wallabies or people illegally harbouring them.
The main methods of killing the pest were cyanide pellets and ''dog and gun''.
''When we're dealing with wallabies in low numbers, a huge effort to get one wallaby could be massive for us.''
Danseys Pass farmer Simon Hore said if the problem was not contained, the cost to farmers would be ''quite extraordinary. It could become even worse than rabbits.''
The regional council will hold another meeting at 11am today at the Tarras Hall.
