Ms Lambert said the reason that the decision had been pushed back was currently there was no capacity in the council's science team to complete the work required to the level in the timeframes set.
She said as such an external consultant with requisite qualifications and experience in environmental flows and aquatic ecology will be sourced to work with key staff to complete this work.
The work, which could begin in July, will cost somewhere between $30,000-$50,000, Ms Lambert said, which means the council's annual plan will need to be amended.
While the environmental flows made the agenda, two noticeable absences from the docket are the monthly update from the council's investment company HBRIC and the long awaited Deloitte report from its peer review of the Ruataniwha dam's business case.
Chairman Fenton Wilson said the reason for the first absence was HBRIC "don't really have a lot to add" over what was presented to councillors last meeting.
"The discussions are getting close to an end that much is evident, but there has been no report as such added," he said.
In regards to the Deloitte report, while he was "hanging out to see it as much as everybody else", he was not too concerned about its absence.
"It's not there because they [Deloitte] are still waiting for further information," he explained.
