"However, we strongly believe our more defined regional model is a better solution for Hawke's Bay than what Government proposes," she said.
Little said the Hawke's Bay model aligns with Government's reform objectives, but unlike Government's plans, would also ensure Hawke's Bay's communities retain local control and ownership of Three Waters assets.
It also aligns with the Communities 4 Local Democracy approach, supported by about 30 councils nationwide, he said.
"Support from Auckland and Christchurch means there is now support from councils representing more than two-thirds of New Zealand's population," he said. "Surely now the Government will listen, and begin a new constructive conversation based on what the majority of councils and New Zealanders want?"
A Crown funding support mechanism would help transition to a regional water model in an affordable way for all of Hawke's Bay's communities, said CHB mayor Walker.
"We are committed to working together to achieve the very best outcome for the people of Hawke's Bay, and we are looking forward to constructively engaging with Government to make that happen," she said.
The mayors say the Hawke's Bay model will achieve the efficiency and affordability and resilience outcomes for Hawke's Bay's drinking, waste and storm water services and keep decision-making local.
It would also ensure co-governance and satisfy the principles of Te Mana o te Wai, meet Hawke's Bay councils' regional investment objectives and principles (including better alignment with regional planning and freshwater management), ensure the new water standards set and monitored by Taumata Arowai are met, and mean communities have meaningful input into planning and management of their water services.