But he hopes farmers and the Otago Regional Council (ORC) may be able to find some common ground as both proposals progress.
It was announced this week the independent irrigation companies in the Manuherikia Valley would amalgamate into Manuherikia WaterCo to do final studies into the Falls Dam proposal, to either raise the Falls Dam by about 6m or build a new low dam.
The announcement followed $815,000 of funding from Crown Irrigation Investments, and landowners in the Manuherikia Valley who had registered interest in the scheme will now be asked to contribute $25 per ha of money previously pledged towards the project. At this stage landowners representing 13,000ha in the Manuherikia Valley have registered interest in the new scheme.
However, Mr Kane said the ORC’s minimum flow process for the Manuherikia River had created uncertainty among farmers and impacted on the Falls Dam proposal, meaning interest from landowners had been lower than expected.
"It’s because we don’t know what it [the new minimum flow] is. It certainly creates a degree of uncertainty."
Some farmers and irrigation leaders have criticised the ORC process, saying it has suggested unachievably high minimum flows that would threaten farming operations. They have also said ORC data did not recognise the Manuherikia catchment went so dry in drought years, and that stored water from the Falls dam augmented the Manuherikia River.
Mr Kane said this week it was acknowledged the minimum flow of the Manuherikia River was likely to increase. But he hoped the ORC was taking on board farmer feedback when setting the minimum flow, and said the ORC response to a recent delegation was "reasonably open and constructive".
"They [ORC] did acknowledge that they need to take another look at this area ... They have agreed to work with us to make sure the hydrology model for the catchment — theirs and ours — is reasonably well aligned so that we are all operating on the same basis."
ORC director of policy, planning and resource management Fraser McRae said to suggest a "compromise" between the ORC and irrigators "suggests a misunderstanding about the purposes of each of these studies and the data they use. The ORC’s study addresses maintaining river flows while the Falls Dam study addresses keeping the irrigation dam full".
"The Falls Dam crosses the flow of the river, so it interrupts the full flow of the river. Any management of the dam needs to respond to the total take of water by allowing some of the flow to continue. This is seen as the dam having to release stored water just to keep the river flowing," Mr McRae said.
Waitaki MP Jacqui Dean said she hoped the ORC and farmers would find "some common ground" about the suggested minimum flows.
"I’ve spoken to farmers on several occasions and I acknowledge their concerns about the council’s proposed minimum flows and the effect that they could have on farming, orchard and winegrowing operations in the region. It’s essential that the environmental values of the river are protected, but this has to be balanced against economic and social factors."
"I would like to see both parties talking these issues through. I believe that both parties have the best interests of the Manuherikia River at heart and that a viable solution can and must be found."
The cost of the different Falls Dam proposals range from $28 million to $68 million, with a cost to landowners of between $1875 and $4000 per ha of irrigated land.
