He illustrated the impact of adding value with a slideshow of the large commercial areas that had grown around the city.
Washdyke, in particular, was now home to the likes of McCains, Seedlands, large flour mills, and a large Fonterra plant.
The flow-on effects of irrigation extended into the community, with the expansion of other businesses such as trucking companies, and housing.
Selling the scheme to farmers was difficult in the early stages, Mr Howey said.
"When you are living in the dry you tend to be risk averse. That mentality was in our area, the tendency to be conservative without reliability of water supply."
Those farmers who did invest were now seeing the returns, with irrigation from the Opuha dam creating more than $40 million per annum farm revenue in the region, he said.
Along the way, environmental considerations were given priority, and an increasing amount of time was being spent on considering such issues.
Since 2007, the Opuha scheme has been 100 per cent farmer-owned.
That model was one Tikokino farmer Mr King said was imperative for the Ruataniwha scheme.
"I'm delighted TrustPower has gone. We don't want someone like them clipping the ticket, we need to own this thing."
He suggested the Hawke's Bay community, both farmers and business people, raise $50 million to invest, and called on the CHB District Council to contribute $10 million.
"We have to have this thing, we have to make it happen."
Mr Newman said the minimum amount for such investment had been calculated at $50,000, and they were looking for a commitment of 40 million cubic metres of water uptake by farmers.