Half of the top management layer at the Auckland Council will depart within months, mostly as part of a planned overhaul.
Council chief executive Stephen Town said the changes will bring in new ideas as the four-year-old council entered a new phase.
He said most of the changes have been planned since early last year, and won't be difficult to work through.
"We've done a lot of the planning and the really hard graft of establishment, and now we are into building momentum on implementation and that is a good time to do a refresh."
The chief planner, governance director and human resources director will see out out extensions to contracts which expired last year and leave within months.
The council was also close to replacing its chief financial officer who left four months ago, and its Civil Defence head has also chosen to go.
Mr Town said none were getting special exit payments.
He said while there were no planned cuts to salary levels, newcomers might start slightly lower on the scale.
"Part of the message from the new council to me as the new chief executive in 2014 is that they wanted to see restraint exercised in executive salaries, and we will be making sure that we attend to that," he said.