Councillor Wilson described the news as "thrilling", and council civil defence manager Neil Brown said the radar would provide a new tool during weather events.
Nine radars in New Zealand -- including three in the South Island -- allow the public to view the movement of rain bands and their intensity in the last hour.
The cost of a radar has been estimated about $3 million.
Otago has been covered in part by the two Southland radars but there have been calls since 2008 for the region to have its own.
Ms Bridges said because of the curvature of the earth, the beam from the two Southland radars did not get as close to the ground as the MetService would like.
The rain radar would also help improve the thunderstorm warning service in the region, she said.
Councillor Wilson said a radar would have helped the city's response to recent flooding by providing better information.
Farmers and contractors, when planning what they were doing, would also benefit from knowing exactly what rain was coming.
That meant an economic benefit.
Mr Brown said the confirmation of the new radar was "extremely good news".
In an intense, short event like the recent flooding, it was important to act quickly, and at present the only tool available was Otago Regional Council rainfall monitoring.
"It's about that higher level of certainty about what's coming and when."