Now South Taranaki District's mayor and councillors have signed a letter to Local Government Minister Nanaia Māhuta to express their "absolute dismay, disappointment and frustration" with her making the reforms compulsory.
The Government initially said councils could opt out of the reforms, but last month Mahuta announced all districts must be included.
The South Taranaki councillors' letter said compulsion "is wrong on so many levels, it's anti-democratic and in our view represents a major breach of trust".
The councillors wrote that the minister and her officials had consistently said there would be full public consultation on the change.
"You have broken your promise and commitment and taken the decision-making out of the hands of the people who actually own the assets.
"While we acknowledge that there is a need for regulatory changes in the three waters activities, this move to force councils to participate without public consultation is totally unacceptable.
"The South Taranaki District Council demands that you reconsider this decision and do what you said you would do, which is to give our residents an opportunity to have their say on this matter."
When she announced the reforms would be compulsory, Mahuta said they were not popular but were necessary to fix what was a long-term challenge.
"No one council can fix the scale of the challenge by themselves and nor can they ignore the substantial benefits that this reform begins. To highlight this point 64 per cent of councils don't have water revenues to meet the full costs of running services and assets.
"We've had years and years of underinvestment in water infrastructure and now is the time to do something about it."
In response to objections, Mahuta has appointed a working group of local government and iwi representatives to recommend how to strengthen governance and accountability.
The group includes Taranaki's Jamie Tuuta and New Plymouth mayor Neil Holdom.
Even before the reforms were made compulsory, South Taranaki mayor Phil Nixon had in September expressed concern.
"Effectively we'll have no direct control over the proposed water services entities as presented and we can't see how the new entities will be responsive and accountable to our communities."
In a submission to the council, Ngāruahine raised similar concerns; Te Korowai o Ngāruahine Trust feared local views would be overridden by larger iwi.
"There is concern that under the proposed Entity B, mana whenua representation for hapū and iwi of the Taranaki region will be poor given the large confederations of Tainui, Te Arawa, Mātaatua and Whanganui."
Te Korowai also said investment would be needed to address rural shortcomings.
"From the perspective of a rural iwi, we are uneasy with the focus on urban growth and development. This will potentially privilege larger urban centres with existing infrastructure capacity and capability."
Te Korowai said Government consultation had been rushed and superficial, and made worse by reforms happening at the same time: the Resource Management Act overhaul and the boom in Māori seats at council tables.
"We have not had adequate time to consult with our hapū who are key stakeholders as both community members and mana whenua."
But Te Korowai's analysis said reform could also bring benefits, including enhancement of rivers, increased participation in decision-making, and safe and affordable water for marae and papakāinga development.