He said while there had already been a feasibility study carried out, a new independent review was needed.
"It can't just be somebody we get on board for our own efforts. Sport New Zealand have offered to fund that, or at least partly.
"That feasibility study might say 'yeah this is a goer or it's a goer if you do two sports and this' but that will form the basis of any provincial growth fund application.
"We'd need Sport New Zealand to support it because Sport NZ advise the minister and the Minister of Sport would be a key individual in ... giving the green light in the Provincial Growth Fund."
The Regional Velodrome Development Trust's spokesperson, Leigh Grant, was still confident the project was solid.
"We're quite happy with Sport New Zealand coming on board and doing a peer review and feasibility [study]. We have already done those," Grant said.
"We're pretty confident that what we're asking Sport New Zealand to do, they will come up with the right answers."
The trust itself has raised more then $3m for the project. Council has agreed to contribute $1m. Grant reiterated the community wanted the velodrome roof.
"This is a project that the community are really, really getting behind in a big way. I think that we've already had two referenda. Each time those have come back, the velodrome is a number one priority.
"We have a very good relationship with council. Hamish has basically said that 'hey guys we need a roof on the velodrome'. They're very, very supportive of what we're doing."
McDouall said trying to ensure the $6m promise from central government had been "very frustrating".
"We wrote a letter a year ago to the Prime Minister who had, during the election campaign when she was leader of the opposition, affirmed the promise from the then National Government of around $6m.
"However ... we received a reply that it had been directed to Shane Jones as minister of regional development.
"Our assumption from that - right or wrong - [is] that it's part of the Provincial Growth Fund and that seems to be where the money has ended up. It was in the budget before and it just seems some budget pots have been shuffled around a bit and poured here and there and that $6m ... is with Shane Jones.
'I don't think that's right. It was a budget line under the previous government and it was discreet and it was for us."
He said the feasability study from Sport New Zealand wouldn't change expected cost.
"The feasability study is not a value of engineering ... it's really about its usage, it's not an architectural thing or a quantity surveying thing. It's about the use it will get - the economic benefit to the community, that kind of stuff. It's not assessing the building at all."
McDouall said it was likely the study would be carried out in the first six months of 2019.
