He was critical the report had not been released yet, in light of it being almost 10 years since the last guidance on coastal hazards and rising seas was issued.
Figures from NIWA studies in 2015 were included in the report and showed that the risks for resident coastal populations, buildings, roads and railways in Hawke's Bay were second only to the Canterbury region.
In terms of population, 8740 households (24,747 people) were at risk, along with 19 kilometres of rail, 169 kms of local roads and three kilometres of arterial road.
The issue was not new for local authorities and across the region efforts were underway to identify the risks.
The defining long-term strategy for managing coastal hazards between Clifton and Tangoio was that being developed through a joint committee made up of representatives of Hawke's Bay Regional Council, Hastings District Council, Napier City Council and Iwi.
Hawke's Bay Regional Council chairman Rex Graham said the work had been comprehensive and not quite finished yet, but as soon as it was the findings would be released to the public.
He questioned why the government was not taking the same approach to informing the public as soon as possible.
"The public need the information so they can understand the risks and make decisions based on their perception of those risks.
"People have different perceptions - what some consider a big risk, others will not be so concerned about and it's their right to make their own commercial decisions - they just need the information.
He said he found it extraordinary that this report had not been released yet.
"It's like they think people are children that can't face the realities of global warming - they aren't - they will make responsible decisions if they are given the information.
"Hiding the information is never a good idea."
Asked why the report had not been publically released yet, Climate Change Minister Paula Bennett said the Ministry for the Environment was asked to carry out more consultation at the request of stakeholders, community groups and coastal residents groups who felt they hadn't had enough time to consider the draft guidance.
The Ministry was about to carry out that work, she said.
"It is an important document, so we need go through a robust process to ensure it is accurate and appropriate before the final version is published."