Mr Mackie (57) will start as the manager of the water and infrastructure department for the New Zealand arm of United States engineering consultancy firm Aecom in late May.
He will be responsible for the company's water and infrastructure work in the South Island and lower North Island, in charge of two teams, one in Christchurch and one in Wellington.
Mr Mackie has been the council's water and waste services manager for six years, during which time he oversaw several major projects that significantly impacted on the structure of city's water and waste infrastructure, including the establishment of the Tahuna wastewater plant and the three waters strategy project.
"A lot of work has been done that the whole [water and waste services] team can be justifiably proud of," Mr Mackie said yesterday.
The chance to be part of a the reconstruction of a major city, especially one so close, was exciting, he said.
"It's an opportunity to really make a difference and I think I can do that."
He would miss aspects of Dunedin, and intended to commute from Dunedin until later in the year, at which point he and his wife would relocate to Christchurch.
Council infrastructure services committee chairman Cr Andrew Noone began yesterday's committee meeting by saying everyone was saddened to hear of Mr Mackie's departure.
He expressed the committee's gratitude for Mr Mackie's hard work, innovation and restructuring over the past six years.
"When I think about the number of projects and plans introduced in your time, you were the major driver of those decisions."
Last year, two members of the council's executive management team took voluntary redundancy - former customer services general manager Grant Strang in October, and former community life general manager Graeme Hall in November.
