Far North Mayor John Carter said signing the MoU was a non-binding commitment, which did not require councils to commit to future phases of the reform, but the councils could now access $14.14 million in government funding (FNDC $5.90 million, WDC $5.89 million, and KDC $2.35 million).
None of the councils signed happily, however.
"There's a sense of being strong-armed," Kaipara Mayor Dr Jason Smith said, while Cr Phil Halse (Whangārei) said the reforms were the most significant in local government in his three decades' experience, and were about driving the councils into a unitary authority.
Whangārei Mayor Sheryl Mai said the MoU had to be signed to protect ratepayers' Three Waters investment.
"We must be around the table safeguarding the significant investment our ratepayers have made in these assets over the years," she said at her council's August 27 meeting.
"If we choose not to take part in this (signing) we can't take part in discussions, we won't be part of making decisions about where to from here."
Kaipara's deputy Mayor, Anna Curnow, said signing was a "tentative step we are taking with our eyes wide open."
The council chief executives will now prioritise which projects they will use the money for, while Innes has called for a governance-level steering committee.
WDC general manager infrastructure Simon Weston said one key piece of work would be to look at options for a regional and multi-regional amalgamated water entity.
This included investigating a regional and a multi-regional water reform entity. There might be a Northland waters entity, Northland infrastructure entity or other alternative deemed suitable for Northland.
A major driver in councils signing the MoUs was to ensure access to the one-time-only first funding, particularly for the drought-challenged FNDC, deputy Mayor Ann Court saying a new water entity would take on council Three Waters debts as well as assets, although Cr Rachel Smith warned of significant costs in infrastructure upgrades and maintenance.
"This is going to be an expensive exercise. We cannot rely on our ratepayers to fund the catch-up," she said.
Another motivation for signing was ensuring that the councils were part of shaping Northland's reforms.
"We must be at the table, as much as it irks me. We have to get into the sandpit and probably flick sand in people's faces," Kaipara councillor Karen Joyce-Paki said.
Water poverty was a massive issue, she added, and communities deserved access to sustainable water.
"We can't be seen to be rolling over. We want our broader outcomes for our community," she said.
Clendon said Three Waters provision issues would not be solved by the government's "clear" amalgamation push, however. More money would be thrown at boosting water quality and management, and it would be that money, rather than amalgamation, that made the difference.
That increased spending, he added, would in turn mean people paying more for their water.