Mr Cairns is not standing in the upcoming local government elections, instead choosing to focus on his commercial real estate consultancy.
Yesterday was the council's last meeting of its three-year term and Mr Cairns' fellow councillors, deputy chairman Stephen Woodhead and Cr Gretchen Robertson, paid tribute to his work during three terms on the council, two as chairman.
Cr Robertson said Mr Cairns had taken on the chairmanship when the council was at a low point, but had built a team and led it through some major projects and difficult times.
"You have been an amazing and inspiring leader."
Mr Cairns was "just as comfortable in his gumboots as in a silk tie" and was an astute judge of character, she said.
Cr Woodhead said Mr Cairns' pragmatic approach and sense of humour served him well when dealing with some difficult issues.
"Otago is a much better place. Council is much stronger for your time and energy."
Under Mr Cairns' leadership the council had been able change the attitudes of many, particularly Central Otago landowners, putting the regional council in a much stronger position, Cr Woodhead said.
He had achieved much as chairman of the regional affairs committee and as a member of the Local Government New Zealand national council.
"Local government as a whole is a lot better off for your input."
Mr Cairns said the job as chairman, at times, had been a lonely one and he appreciated having the support and confidence of councillors, especially when he was "winging it".
He believed his decision over the council's new building was "at the time the right decision" and he was disappointed not to have taken part in the conclusion of the Port Otago merger "one way or another", he said.
He thanked council staff, stakeholders and the mayors and chairmen of other local authorities.
The council presented him with a painting of Purakaunui by Sheryl McCammon.
The meeting was attended by Mr Cairns' family, and others including Clutha Mayor Juno Hayes, Dunedin Mayor Peter Chin and former Dunedin Householders and Ratepayers Association chairman Syd Adie.
