Meeting papers said there is a growing group of councils which, while supporting the establishment of a new regulator and standards, oppose the creation of four regional entities to deliver the service.
The Government launched its proposal in July last year but after receiving feedback from councils announced three weeks ago it will go ahead.
Councillors were told the $15,000 would be an "initial" contribution from a contingency fund, and the council could consider increasing that support at a later stage, or withdraw from the partner group at any time.
A summary said councils opposing the reform model believe each Three Waters asset owner has the right to determine with their community how best to meet the standards and that there are a number of alternative and viable delivery models that would be supported by councils and ratepayers across New Zealand, for the future of drinking water, stormwater and waste water services delivery.