Mr Cooney (50) finishes in the role today but will stay for a month to assist his successor, Phil Melhopt, who was Timberlands West Coast's chief executive.
He took up the role in 2002, returning to his home town of Alexandra after a stint in Oamaru.
His background included teaching and local government work.
His time as chief executive has coincided with a period of rapid growth in the district.
"That's certainly been challenging, and driven much of what we do as a council," Mr Cooney said.
"Growth obviously puts pressure on our assets, and indeed every part of our organisation is affected in some way, from assets through to planning, building and roading."
During his first year as chief executive, there were 22 building permits issued for dwellings in the district, with a total value of $16 million.
"As a comparison, last year there were more than 200 consents issued for dwellings, valued at about $100 million.
"Now, we've reached a plateau and it's remained steady."
Employing staff to cater for that growth, especially in the council's planning and building department, was an interesting exercise.
"You'd advertise for more planning staff and by the time they started work, you already needed even more," he said.
Development activity in the area meant there were also more inquiries made about planning and roading matters.
Growth was a good problem for a district to have, as it drove investment, job growth and population growth.
"At one stage, it was hard to recruit staff here because it was seen as out of the way, and people were worried whether their partner would manage to get work here.
Now, of course, that's completely changed and people shift here knowing that it's easy for their partners to find work."
One of the highlights of his tenure was working on the regional identity.
"That was really rewarding, and communities stepped up to have an influence on what was happening in their area and to say what was important to them."
Finishing the district plan was another highlight, along with the completion of the rural study, which set guidelines for rural subdivision and building.
Mr Cooney was pleased to have been involved in the systems thinking approach, which aimed to improve the way the council delivered all of its services.
"It's been great to see that implemented in different departments and to see the improvements first hand."
He will work on contract for the council for about three months before following up other job opportunities.
Mr Cooney ruled out continuing in local government and said his future employment would revolve around helping businesses and organisations improve their operation. He plans to work on contract.
There were "no regrets" from his time at the council, he said. "I will miss working with the team here and the elected members. They're a good bunch of people."
But he would not miss being in the limelight.
"That's not me at all. I won't miss seeing my name in the paper."
More family time is on the agenda and he and his wife, Robyn, are looking forward to becoming grandparents in July.
"So you'll see me out and about, pushing a pram."
