Given that the amount of tranche 2 groundwater available under Tukituki Plan Change 6 had been set by the Board of Inquiry, Mr Maxwell warned that attempting to change the plan or fight the consents would be "very, very expensive," and likely require extensive new science, appeals, consultants and lawyers.
"It may well fail at the end of all that," he said. A more practicable solution would be for the CHB District Council to put down a community bore at a secure depth for residents, he said.
"Rather than several hundred individuals having to resolve this issue themselves, it is probably far more effective for the community to work with the District Council to investigate construction of a community-supply bore — a bore at a depth that will never run dry — as a pragmatic option," Mr Maxwell told Local Focus.
CHB mayor Alex Walker rejected that, saying security of water supply was a regional council responsibility.
"If only it was so easy," said Ms Walker. "HBRC is responsible for managing the quantity and quality of water in our rivers and aquifers. That is why the residents of Ongaonga and Tikokino took a petition to the regional council. They have an issue with water security and how water is being managed," she said.
Residents across the Ruataniwha basin experienced issues with their private water bores, said Ms Walker, and not just in Ongaonga and Tikokino.
"So CHBDC spending millions on water bores, treatment plants and piping networks would never solve the problem completely anyway."
Council chief executive Monique Davidson said in the past, council had investigated creating reticulated supplies in Tikokino and Ongaonga which were possible practically, but would require "significant work".
She said a council-owned supply would not work if only some residents wanted to be connected. It would also require the support of HBRC and Hawke's Bay DHB as well as significant investigation into water quality, as there were potential complications from iron and manganese in the area.
She said a reticulated drinking water supply would also likely require the creation of a reticulated waste water system soon afterwards.
"It is likely that existing septic tank and effluent field systems in these communities would not cope with the additional water provided by a reticulated drinking water system."
Ms Davidson said council officers had again held several discussions with residents during its recent LTP process about a council-owned supply, but opinions were "divided".
"There is no provision in [council's] current LTP for creation of a council-owned supply. That does not however say that is not an option for council to consider in the future," she said.