Environment Canterbury is proposing a controversial amendment to the Waitaki water catchment plan, effectively reducing its minimum flow by nearly 30 per cent for four months.
The Waitaki Catchment Allocation Plan, drawn up after a Government call-in of water-right applications back in 2004, sets the minimum flow for the river at 150 cumecs, to allow for both hydro generation and good environmental qualities.
However, a draft discussion document proposed by the Canterbury Water Management Strategy's Lower Waitaki committee suggests dropping this to 105 cumecs for pre-2006 issued consents for October to January, and between 125 to 145 cumecs for them in other months.
Although any proposed changes will eventually go out for public consultation, Government legislation sacking ECan's 14 elected councillors and replacing them with seven appointed commissioners also removed the right for people to appeal against decisions to the Environment Court.
Ian McIlraith, who is chairman of the Waitaki River Society, said he was concerned the changes were being made for political convenience without adequate science or evidence.
"When the Waitaki Catchment Allocation Plan became operative in 2006, it was a democratic process, and involved a lot of solid evidence and reasoning for its decisions," Mr McIlraith said.
"We haven't seen any convincing information and reasoning for these moves.
"On the other hand, our society has reliable evidence that there is sufficient flow in the Waitaki for irrigation without lowering the minimum flow."
Mr McIlraith was concerned further lowering the rivers' minimum flows could detrimentally affect their quality.
The Canterbury water management zone committee members are all appointed, and feature a mix of representatives from the regional council, district councils and the community.
They are tasked with recommending limits to ECan.
Lower Waitaki committee chairman Robin Murphy said nothing was a fait accompli.
"It will go through the submission process like anything else, we want to get as much community buy-in as early as possible before that happens," he said.
Mr Murphy said there were several existing consents that did not comply with the current limits, and the committee was trying to find a decent compromise.
But fellow society member Dugald MacTavish said such an amendment was unnecessary.
"It seems to me that ECan and the zone committee are trying to pass the buck for not bringing the existing resource consents into line before allocating new consents.
"I don't know whether it is right that the river should pay for that mistake," he said.
- The Timaru Herald