Some Rotorua leaders have described Three Waters as "very bad legislation" and "profoundly flawed".
But, another says it is "a much-needed reform" and initial concerns have been listened to.
The Government announced on Friday it would move forward with the Three Waters proposal to give control of New Zealand's water services to four newly-created entities, instead of local councils.
The entities would be run by boards that are appointed by a panel, which is appointed equally by councils and mana whenua.
One change to the initial proposal was local councils would now have a shareholder's stake in the created entities, potentially allowing for more influence over their operations.
Rotorua MP Todd McClay of National said the community was "disappointed" and he believed the water assets paid for by locals would be "stripped away".
"Frankly, it's not good enough - the government has let the city down."
McClay described the council's ownership stakes as a "sleight of hand" and he believed the council would have little say if any.
"It's very bad legislation, and the government should actually not go forward with it."
McClay said concerns about privatising the entities were an attempt to "shift the debate sideways".
"Our water shouldn't be privatised, and it wouldn't be under a National government."
He said, in his opinion: "This is a government that is ... not talking to nor considering the concerns of ratepayers or voters."
Rotorua-based Labour list MP Tamati Coffey said Three Waters was a "much-needed reform that will save ratepayers thousands of dollars a year, countless tummy bugs from contaminated water and deliver better water infrastructure for us all".
"At the heart of councils' concerns have been the issues of ownership and voice. By accepting the majority of the recommendations made by the independent Working Group on Representation, including a shareholding plan, we have listened to these concerns and modified our proposals accordingly."
Wairiki MP and Te Paati Māori co-leader Rawiri Waititi said the party would not support Three Waters until the Waitangi Tribunal had ruled about water ownership.
In his opinion, "Maori ownership and customary rights to water hasn't been recognised."
He was concerned the Three Waters entities would not reflect the wishes of smaller groups.
"Where is the voice of smaller councils? Where is the voice of hapu and iwi?"
Under the plan councils would have "shares" in the new water entities with each council getting one share per 50,000 people in its district. Each council will have at least one share.
Waititi was also concerned about how the entities would be arranged, and thought the "intricacies haven't been thought out very well".
"It's a move towards the right direction, but there's still a lot of work to be done."
Taupō's National MP Louise Upston said Three Waters was "unacceptable".
"What the Government is really saying is that locally elected councils are unable to make decisions for themselves.
"National agrees that the current system needs improvement to ensure all New Zealanders have access to clean, safe water, but [Three Waters] is not the way to get there."
Rotorua mayor Steve Chadwick said, "at first glance there are still some unanswered questions.
"I'm not yet reassured about local input. We need clarity and details around the governance model and what localism and local control looks like, other than shareholdings."
She said the council would be analysing the government's response to the working group recommendations "against our own initial position and the concerns we expressed" and what was best for the district.
"We haven't yet had the opportunity to do that as a council to enable us to then consider if our initial position changes and what steps we want to take from there. We will be doing that in the near future."
When asked to respond to the MP's criticism, local government minister Nanaia Mahuta said the reforms were "fundamentally...about delivering clean and safe drinking water at an affordable price".
"With the key issues now addressed, we cannot afford to wait any longer. The costs to communities and ratepayers are just too big to ignore."
Responding to the criticisms, Local Government Minister Nanaia Mahuta said the co-governance arrangement would "mutually reinforce the sustainability of water management and keep public ownership of water entities as a top priority, while prioritising the benefits to all communities big and small".
"Co-governance arrangements exist at the regional representative group level, where 50/50 governance oversight between councils and mana whenua is exercised for the broader wellbeing and benefit of the whole community.
"The decision-making process that ensures that community priorities are reflected, will be at the regional representative group level and also through the establishment of sub-regional groups. It will enable communities to prioritise what is important to them."