The report focuses on the future economic impacts felt directly in the TANK (Tūtaekurī, Ahuriri, Ngaruroro and Karamū) and Tukituki catchments by the primary sector of the economy, which includes horticulture and fruit growing, sheep, beef, deer and other livestock and grain farming.
It predicts that a "do nothing" scenario in terms of water security and climate change post 2060 will have a significant impact on regional GDP and community wellbeing.
Forest & Bird freshwater advocate Tom Kay said the statement released by the council after Thursday's meeting "failed to acknowledge that there are numerous other things Hawke's Bay could do to address the impacts of climate change".
He said moving to more regenerative models of agriculture, restoring wetlands, lowland forests, and riparian vegetation to store water and carbon in our soils, among other initiatives.
"The report HBRC commissioned makes no reference to these options," Kay said.
"It also fails to mention that many of the land uses we're trying to 'protect' [like] dairy, beef, horticulture, through water storage investigations like the ones council is commissioning, contribute significantly to climate change.
"I can't help but feel like council is just paying for all the science it needs to build some water storage infrastructure and uphold the status quo.
In response, council chief executive James Palmer said the report was particularly focused on "the relationship between water security for irrigation and climate change".
He said the council was interested in commissioning research on the wider impacts of climate change on the regional environment.
"It would be disappointing to be pigeon-holed without fair acknowledgement given to the full suite of interventions funded by the ratepayers of HB," Palmer said.
Graham agreed water storage "is only part of the future story" for Hawke's Bay.
Other scenarios in the report predict the region's GDP to fall by up to $120 million per annum by the middle of the century if nothing is done about water security to adapt to the impacts of climate change.
Graham said the report was important as it was the first piece of analysis about the economic impact of climate change focused on the primary sector — the largest and most vulnerable extractive user of the region's freshwater resource — under the council's water security work programme.
"We need to focus on developing a range of interventions, not just one or two solutions, to be resilient in our future supplies of water that match our future demand, particularly relating to climate change."