If it goes ahead with plans to notify the changes at the end of the month, farmers would be backed into a corner, Otago Federated Farmers president Mike Lord said at the council's public forum yesterday.
He said there was widespread concern that with Proposed Plan Change 6A Water Quality becoming active on April 1, any farmers contravening the new measures would face compliance action.
The proposed changes would require run-off from land to meet certain standards.
Farmers who had planted winter crops without sedimentation mitigation were just one example of this, he said.
Mr Lord, while praising the regional council's consultation so far, suggested postponing notification until June would enable the council to undertake more consultation with farming leaders so there was more confidence those in the industry could comply.
"There is too much detail we do not know. A lot of farmers think this isn't going to work."
Cr Gerry Eckhoff, who was also concerned about a lack of consultation on an amendment to the changes identifying lakes Hawea, Wanaka and Wakatipu catchment areas as nitrogen-sensitive, backed delaying the notification.
He also worried what would happen if an environmental organisation made a complaint about land-users' practice under the new rules.
"I'm concerned we are jumping the gun a little in terms of implementation."
Cr Doug Brown said many farmers were wondering what the detail of the legislation meant for them and believed they had "not a bull's roar" of meeting the new standards.
Cr Michael Deaker said he was concerned the council could lose the positive momentum it had gained in the past 18 months of consultation if it pushed on.
Cr Bryan Scott said while he had sympathy for those concerns, it was not time to be nervous. There would be challenges and the consultation process that followed notification would give people the chance to raise issues.
"It's not time to dilly-dally. Just do the consultation and get on with it."
Cr Gretchen Robertson said the council risked losing respect if it delayed notification.
Chairman Stephen Woodhead said the Resource Management Act required that any notification of a plan change relating to water became active but that did not mean the "compliance men" would be out on April 1.
"We all understand ... there is an awful amount of work to be done in education and transition."
He hoped the concerns would translate into good submissions.
Chief executive Graeme Martin said after the meeting unless there was a "gross and wanton" incident which would breach present water plan regulations, a transitional and educational approach would be taken.
"Will we force it to the letter of the law? Absolutely not, unless it's gross and wanton."
Councillors approved the amendment and despite a failed attempt by Cr Eckhoff to delay the notification of the plan to September, they agreed the notification would go ahead on March 31.
Cr Eckhoff had his objection noted.