These rest upon a series of early reports predicting how land use would change - adding more and different output and profit on a farm-by-farm basis - if only stored water were made available. The authors of the Macfarlane and Butcher (and other reports) made assumptions about shifting farming systems (e.g., more dairying, more orchards and vineyards), water and commodity prices, costs of mitigating environmental impacts, and the actual productivity of farmers.
Each report built upon the ones preceding, accepting previous assumptions without challenge. Hence claims of 2500 'new' jobs and $235 million in added annual value to the region's GDP were born.
But consider the fine print.
For example, in estimating farm profitability, Macfarlane used a water price of 20 cents per cubic metre (but the price is actually now set at 26 cents, with an inflation clause). He also forecast a substantial shift to dairying; an assumption HBRIC now dismisses.
In the meantime, though, another consultant assigned to translate Macfarlane's projected farming intensification into job and output growth, assumed all water would be taken up within 8 years of the scheme becoming operative (even HBRIC would smile at that). He said 500 of the permanent farm jobs (out of a total of 1,160 such jobs) would come from increases in orcharding and vineyards. Local experts dismiss that prospect, noting far better conditions for such growth elsewhere in the region. Moreover, the consultant said regarding his other projected 1,090 jobs (in processing support): "there is enormous uncertainty with these numbers because of the uncertainty as to the mix of irrigated land uses".
So half the originally predicted 2,500 jobs (eventually got trimmed to 2,250 jobs after closer scrutiny, are strongly hedged by the consultant. And the most of the other half come from predicted activities - orcharding and grape growing - with dubious prospects in CHB.
That consultant also estimated up to 9,000 containers (TEUs) of additional produce coming through Napier Port; HBRIC rhetoric has inflated that number over time, with no supporting analysis, to 15,000 containers.
Regarding his overall job and GDP projections, the consultant cautioned: "The impacts reported here should be seen as the likely upper limits to the net impacts on the community." A warning long since buried. And all this only at 100% water uptake.
Two other sets of assumptions are even more disturbing.
The first involves nutrient leaching. Consultants considered the cost of cutting back the nitrogen leaching that everyone concedes would increase substantially with intensified farming. Ten different types of most likely post-irrigation farming systems - dairying on various soils, cropping, orchards - were modeled. Not surprisingly, the more mitigation measures were needed, the less profitable per hectare the farm, eventually to the point of unacceptable returns on investment.
That report concluded: "The HBRC decisions will be: the acceptable level of nitrogen losses from farms to achieve a target water quality; the mechanisms necessary to achieve and police farm nitrogen losses; and finally the acceptable rate of return from the scheme."
Here you see the seeds of HBRIC/HBRC's attempt to minimise the need to address nitrogen leaching in its phosphorus-focused Plan Change 6 proposal - an approach the Board of Inquiry soundly rejected. A decision HBRIC/HBRC still can't swallow.
The second assumption involves farmer productivity. After considering ALL factors that might adversely affect the economic viability of the scheme, Macfarlane concluded the single most critical factor was that every farmer using dam water had to be a "top 20%" farmer - using best practices in every phase of their operation - to achieve the levels of productivity (and profitability) upon which rosy economic predictions for the scheme were based.
He says: "We note the severe impact on profitability incurred if the investment generates only average productivity. For that reason farmers not wishing or able to generate top 20% performance will either need to decline participation, sell, or transfer management of the property to another person."
But not a week goes by where the farm media doesn't bemoan the reality that most farmers will never attain such 'superstar' status.
Indeed, these days HBRIC advocates simply promise that a new breed of CHB farmer will arise from the ashes of the failed ones to grow highly valuable crops we haven't yet dreamed of - 70% turnover within five years.
At the end of the day, ratepayers are being asked to make an $80 million bet on that prediction (leaving aside adverse environmental consequences), with even greater financial risk if the prediction proves wrong.
To build a convincing economic case for the dam, one must ignore the hedges and caveats in these original reports and latch on to only the most optimistic of the assumptions. No fresh assessment using realistic assumptions has been done, but the ambitious claims remain.
A cascading set of outdated 'best case' assumptions - this is how a house of cards is built. And why the builders of the house must fervently trust in the Dam Fairy.
Meantime, HBRC is promised soon an independent assessment of the project's financial viability by Deloitte. Unfortunately, given the resistance of five councillors, Deloitte's brief specifically excludes re-examining the issues I've raised here.
Fairy dust will do.
Tom Belford is a Hawke's Bay Regional councillor
