A water allocation limit set in 2004 and being newly promoted by the Otago Regional Council would wipe out half the farming operations in the Manuherikia Valley should it be enforced, a local critic says.
Manuherikia farmer and water leader Gary Kelliher, who is chairman of the Manuherikia subgroup of the Otago Water Resource Users Group (OWRUG), said a "nominal" historical figure of 3.2cumec of water allocation for the entire valley had recently been promoted anew by ORC chief executive Sarah Gardner.
But about 8-9cumec of water was used in the valley at present, and about 9000ha of the valley's 15000ha of irrigable land would lose water if the allocation dropped to 3.2cumec, Mr Kelliher said.
It would take millions out of the district's economy and "be the nail in the coffin" for many farming operations, as well as threatening the Falls Dam project.
If fewer farmers bought into it because their operations were threatened, the price of the dam project could double and it could become unviable.
The news of the 3.2cumec target had sent shockwaves throughout the district and farmers were "working on a strategy" about what to do next, Mr Kelliher said.
"Lawyers and Environment Court is expected anyway [from the proposed Manuherikia minimum flow process] but ORC are becoming so entrenched and imbalanced that there are now discussions in meetings about what to do at a higher level."
Ms Gardner told the Otago Daily Times the 3.2cumec — which would not be phased in for about 10 years — was not a "nominal" figure or "target", but the "actual primary allocation" for the Manuherikia catchment in the Otago Water Plan following a 2004 Environment Court ruling around the minimum flow at Ophir.
She said the figure had been agreed to at the time by OWRUG members.
Mr Kelliher said he did not believe that — "it was more likely to be an end outcome that OWRUG could not change".
He said the Manuherikia subgroup had to present publicly to the ORC several weeks ago, as they had been refused a private meeting with ORC staff and councillors in Dunedin.
He was angry at being refused a meeting, and that the 3.2cumec figure had been raised anew by Ms Gardner during a council meeting when his group members were unable to respond.
Ms Gardner confirmed Mr Kelliher's group had been denied a private meeting with staff and councillors, as councillors wanted to ensure the "integrity" and "transparency" of the process and it was "best [for the Manuherikia group] to do [the presentation] in a public meeting".
She said she had raised the 3.2cumec figure publicly at the meeting because the Manuherikia group's presentation had not mentioned it.
Dunstan ORC councillors Graeme Bell, Michael Laws and Dr Ella Lawton have repeated their concerns about the ORC's handling of water issues in the Manuherikia catchment.
"Councillors have not yet seen the science for the Manuherikia ... I would have preferred we had seen the science before ORC went public," Dr Lawton said.
"I do not think it is fair to the community to have gone about it in this way."
Ms Gardner said economic data, a water surety model and cultural and social assessments would be available at the end of this year.