Mr Newman returned to the role of CE before the November local body election, signing a two-year contract. He felt there had been "real progress" on the challenges which faced the region when he first took up the role in 2007.
Two main challenges had been iwi relationships - which had been progressed through the treaty settlement process, and development of the joint plan committee - and civil defence, which now had a coherent framework and strong management team.
Another challenge was fresh water. A large part of Mr Newman's tenure was spent driving the controversial Ruataniwha Water Storage Scheme.
In 2007 water storage was an idea, and over the past 10 years council had progressed to the point where it was understood how to finance, consent, and construct such an idea.
When asked about criticism of the scheme, Mr Newman said he thought people found issue with it as it was a "transformational project" which had changed the status quo for the region, and involved significant amounts of money at a scale the region was not used to.
"It's been amplified to an extent probably ... that the region hasn't seen for a long time so I guess it's been a big controversial process," he said.
"It's much harder to be the protagonist for these things than it is to be the critic of it."
Personal "flak" directed his way went with the territory, he said.
"I think the way I cope and deal with these things is if I personally felt I was getting it fundamentally wrong then maybe some of that criticism would have been valid.
"But I felt that I've worked with a team of people...[who have] been professional and really quite committed on assessing whether we can make this work or not."
Progress on the Ruataniwha Dam stalled with the election of a new group of councillors last year, which shifted the 5-4 split away from supporting the dam. A moratorium on the scheme has since ceased any activity on it, with a review currently under way.
Despite these changes, the CE said he remained optimistic the scheme would progress.
He "would have been delighted to see the ink dry on the paper at financial close", however said he had completed his job in relation to the scheme by getting it to this point.
"All of that work has been done to probably a 95 per cent level and that's really where the hard work is...taking a concept from something that's a good idea to something that's very near to reality."
Last year the other man driving the scheme, HBRIC chairman Andy Pearce, also resigned. Recently Mr Newman also faced criticism about a prosecution against the Hastings District Council.
When asked for a response to speculation he was pressured to leave the role, Mr Newman deferred comment to council chairman Rex Graham.
Mr Graham has denied any pressure from the council.
With his last day being March 31, Mr Newman was now looking to move into the private sector. Before this however, he said he would enjoy a break from "the pressure of this job".
"When I was really involved in the RWSS it was a seven day a week job, 365 days a year. It was one of those things that took absolutely every ounce of ticking time," he said.
"It's going to be really refreshing to actually have a bit of time to sit back and get a clear head, which I haven't been able to have for a long time."
The process of selecting his replacement would be starting immediately, with the successful candidate voted on by the nine regional councillors.