The scheme has been described as the largest irrigation project ever undertaken in New Zealand.
Mr Newman was previously chief executive of the regional council before being seconded to HBRIC.
A recommendation that his pay be increased - through a "temporary higher duties allowance"- was made by the three-member HBRIC board of directors who are independent of the council.
Their proposal was discussed in secret during public-excluded sessions of council meetings last month and again yesterday when councillors voted 5-4 to increase Mr Newman's pay.
Hawke's Bay Regional Council chairman Fenton Wilson said the HBRIC directors who recommend-ed the pay rise included David Faulkner, a former managing Dam boss gets $84k pay rise
director of Fulton Hogan "who is well versed in the challenges and complexities of these roles".
"He [Mr Newman] has moved from a local government chief executive's role - which is a complex role in its own right, dealing with public expectations and public money and other issues - but the range of work he's had to do in this role far surpasses that."
HBRIC chairman Andy Pearce said Mr Newman's role warranted a higher level of remuneration than that of a council chief executive.
"It [Ruataniwha] is a very complex project with multiple streams of work. They're all interrelated. It's a very large project with a $300 million kind of number. We were very much of the view that the additional higher allowances we proposed are entirely consistent with the degree and impact of the project."
But councillor Rick Barker criticised the way the decision had been made, saying an independent report should have been commissioned to confirm what was a suitable pay level for the role.
Councillor Rex Graham, who works with disadvantaged groups as chairman of Flaxmere's U-Turn Charitable Trust, described the pay increase as 'a disgrace'.
He said the increase alone was several times the wages earned by many hard-working people who were on wages of $25,000 to $35,000 a year.
