Mr Butler said the level of opposition to the investment surprised him, given that hundreds of CHB residents turned out at a rally in support of the scheme two weeks ago and a large number attended a Hawke's Bay Regional Council meeting last week where the council voted to invest up to $80 million in the scheme, provided a number of conditions are met.
He said given the boost the dam would provide to the local economy, he had expected more people to write in supporting the investment but believed it was a case of "the silent majority" remaining silent.
The council's stake in the project would be through buying units in the Tukituki Investment Limited Partnership, an investment vehicle set up by Hawke's Bay Regional Investment Company (HBRIC), the commercial arm of the regional council, which devised the water storage scheme.
The Tukituki Investment Limited Partnership - and the entire project - will not go ahead if a number of conditions are not met, including if HBRIC believes it has not received a "workable" consent from the board of inquiry which released its decision on the project and a related environmental plan change last week.
Regional council and HBRIC staff have been studying that decision, which runs to more than 1000 pages, and are due to brief regional councillors tomorrow.
The CHB District Council's proposed $5 million investment would require additional rates funding to repay the $4 million loan from 2020 onwards but the council is confident it could manage the impact within the constraints of its 2012-22 plan.
A common theme in submissions opposing the investment was a call for the council to stick to its core business.
"It's central government's responsibility to fund this scheme, not CHBDC," said one.
Another said the council should be focusing on matters such as roading, water supplies including waste water, rubbish management and inspection services for regulatory purposes. "With a much publicised deteriorating system associated with many of the above items, it would be more prudent to use capital reserves or loan capital to invest in the infrastructure replacement of these core facilities."
Those in favour of investing said the scheme would be good for Central Hawke's Bay, one suggesting the council should invest $10 million.