Readers, who recall that I strongly opposed the Ruataniwha Dam project in a series of Hawke's Bay Today columns published in 2014-16, may be surprised to learn that I'm now offering provisional support for the new improved dam proposal being worked on by a group describing itself as Water Holdings CHB.
I'd like to assure any such readers that my approach hasn't changed, what has changed is the new dam proposal, and who would be expected to pay for it.
My previous opposition was based on the principle that economic development is best paid for by the people who stand to benefit from it.
In the case of the Ruataniwha Dam, the main beneficiaries were always going to be a group of up to a few hundred Central Hawke's Bay landowners who could potentially make profitable use of reliable irrigation water.
But these people were not the main public advocates for the dam, nor were they being asked to pay the up-front costs of developing the proposal, which eventually came to more than $15 million.
That role was assumed, on behalf of regional ratepayers, by the Hawke's Bay Regional Council. And sitting behind this initial funding was the promise of up to $80 million more. Unsurprisingly, this resulted in a huge controversy.
Back in 2014 I wrote: 'If intensified farming from building a huge irrigation dam was going to be highly profitable, and therefore capable of standing on its own feet and generating a wide range of spin-off benefits, there would be no need for the regional council to be leading it.
The council's role would be limited to carefully scrutinising private-sector dam-building proposals and setting conditions for any such proposal to go ahead.'
But now, four years later, the regional council has withdrawn its proposal to be a major funder for the dam and a new group has stepped forward, led by three capable and experienced CHB businessmen.
This represents a huge change for the better.
Nothing is going to be easy about bringing a revised dam proposal to fruition.
As I see it there are three major practical requirements: economic, environmental, and conservatory.
Each of these will have its own political requirements, needing strong support at local, regional and central government levels respectively.
At local level the economic benefits of building the proposed dam must be demonstrated in a sufficiently compelling way to ensure it can be funded by the Central Hawke's Bay community.
Not just by farmers and their families, but by the wider community, including the owners of transport infrastructure, that stands to benefit from local economic development and may be asked, by the Central Hawke's Bay District Council, to approve new resource consents.
Such support can best be demonstrated at the next local government elections.
At regional level the environmental consequences must be demonstrated to be acceptable, at least to the satisfaction of the Hawke's Bay Regional Council, no longer conflicted by being the main funder as well as the referee.
This will need strong demonstrated support from regional ratepayers, through their elected representatives on the Hawke's Bay Regional Council.
At national level there must be sufficient support from our region's Members of Parliament to enable a Local Bill to be passed, permitting the conservation land threatened by the dam to be traded for a new bespoke conservation solution judged by experts to be sufficient compensation.
To be quite clear about this: it will need to be a much better offer than the previous one, which was widely derided by conservationists and was judged illegal, under existing law, by the Supreme Court.
This judgement can only be overridden by legislation.
My expertise is in science, not conservation, but it seems to me to be almost certainly possible for the dam proponents to find some other block of land, potentially even better for conservation purposes than Ruataniwha, and to develop a convincing plan for ensuring its staged development, as a new plant and wildlife haven with guaranteed protection in perpetuity.
Such a plan would still be opposed by some, but in my opinion they would be a minority.
The challenge I put to Water Holdings CHB is 'Can your proposal convincingly address these practical and political requirements?'
If it can, then despite the fraught history of this project, it deserves our support to go ahead.
* Bill Sutton is a former DSIR scientist and former MP for Hawke's Bay.
* Views expressed here are the writer's opinion and not the newspaper's. Email: firstname.lastname@example.org