Chapman has been at Tararua Alliance for two-and-a-half years. In that time, he says the greatest challenges have come from severe weather events that have affected the district's road networks and the closure of the Manawatu Gorge.
"While the gorge isn't part of our roading network, the closure has had an impact on the district's roads."
Another challenge facing Alliance is that Tararua District has the longest roading network in New Zealand and the fewest ratepayers per kilometre of road.
"It's a matter of having to balance out maintaining the standard of the roads on a limited budget."
Chapman's role is to be taken over by Dan Gerrard until a new manager is appointed. Gerrard, who was with Tararua Alliance from the start, says the manager's role is a difficult one to fill.
"A unique skill set is required. The recruitment process is under way and in the meantime I will be the interface between Tararua Alliance and Tararua District Council. I don't really see too much disruption," said Gerrard.
At Wednesday's Tararua District Council meeting mayor Tracey Collis acknowledged Chapman's work.
"You have done a fantastic job in ensuring ratepayers get the best value for money. You have a lot to be proud of and we look forward to having you back."
Collis thanked Chapman for his dedication, the work he had put in on Highway 52 and for building a good relationship with NZTA.
"I thank you for the culture you have created within Tararua Alliance."
Chapman told the meeting what had been achieved was because of a big team effort and a huge range of support.