"There's been really significant changes both within the council and the district as well. It would be safe to say now that Te Wairoa as a district is very much on the world map."
Mr Power said the councillors had "shown great trust and belief in me in allowing me to get on and do things that sometimes, might have appeared to be quite novel".
"Some of those ideas could easily have been seen as being unlikely to succeed but because of their belief and trust in me, we have made those things happen."
Recent achievements of the council included attracting new ventures to the area - from the conversion of the Clyde Hotel to a film school, to the new rail bike adventures on the line between Wairoa and Gisborne.
Of particular highlight was attracting Rocket Lab to the district.
"The impact of space launch on Hawke's Bay is not really fully understood. It's only going to be in three or five years time when people look back and think that's amazing, this has just been such a transformative impact on the Hawke's Bay region."
Mr Power will take up the mantle at Waitaki District Council - based in Oamaru - on September 18.
Wairoa Mayor Craig Little said he was surprised to receive Mr Power's resignation, but acknowledged his contribution to the Wairoa district and to the council.
Mr Power had been instrumental in assisting council in their vision to see Wairoa thrive, which involved halting population decline, changing the perception of the town, and demonstrating it was "a great place to work, live and play".
"We have been through some challenging times over the past three years. The threat of amalgamation was one of the biggest decisions our community and region had to decide on, and Wairoa led the charge in opposing amalgamation within Hawke's Bay," Mr Little said.
"We have come out the other side and the leadership shown during this time needs to be commended."
Because of the work done by Mr Power and council staff over the past few years, "we can confidently say that Wairoa is now firmly on the world stage".
"Who would have thought that we would see Rockets being blasted off from our district?
"Under the stewardship of Fergus, our staff have been able to unshackle themselves and prove that the Wairoa district has a promising future and has the capability to realise its full potential."
The process to appoint a new CEO is under way.