The project has been going for about four years and Mr Newman says in the initial "full feasibility phase" there were about 100 major separate tasks that needed to be completed.
With crunch time now looming for the council to make a decision on whether to give the project the green light - and commit $80 million of ratepayers' money to it - the project has moved into the "final assessment phase".
This has seen the number of tasks doubled and the pressure intensified.
"The deadlines are really tight and it's a job that occupies myself and key members of my team largely seven days a week and upwards of 24 hours a day in terms of either access or thinking time. It's absolutely continual and a fairly unique circumstance," Mr Newman said yesterday.
The work includes securing multiple resource consents for the project, negotiating a design and construction contract, raising capital from a number of investors, working up a mountain of legal and commercial arrangements and signing irrigation customers.
"Probably the most complex bit of this is having to bring all of these elements and relationships together into a whole proposition. We've run this process over a four-year period and on average these projects have taken over 10 to 12 years to get up," he said.
"Every element of it is a challenge.
"What motivates me is to do something that hopefully will be a leading project that is going to create real value for this region for a long time."
His large pay cheque has drawn criticism, including from some of the regional councillors who employ him.
The remuneration hike was the board's initiative, not his, and the ensuing criticism is "just the reality of a high-profile public role," Mr Newman said.
His HBRIC role, and the extra $84,500 allowance, is due to end in the middle of this year once the assessment phase of the Ruataniwha project is completed and - assuming it goes ahead - the relatively mundane role of overseeing the project build gets under way.
There is no certainty the dam project will proceed. It could be thwarted by an unfavourable ruling from the board of inquiry currently deliberating on resource consent conditions, by a council decision that the business case does not stack up or by a legal challenge from affected parties. But Mr Newman says he is optimistic the scheme will be built.
"You never say it's an absolute certainty until it's done but I think our proposition is now very well defined.
"We know where the bits all fit together and subject to decisions that are not in our hands going in a way that is manageable then it's absolutely there to be done."