Members of Hawke's Bay regional, Hastings district, and Napier city councils also attended.
While it was hosted in Hawke's Bay, Ms Delahunty said it was a national issue, but this could not be left to politicians, and it could not be left to corporates alone.
"The most important thing is how we are going to make a sensible, sustainable solution to this issue."
Ms Delahunty said without these conversations she was afraid NZ would lose even more of "the most precious resource we have except for air, and I guess they're going to be selling that next".
Hawke's Bay regional councillor Peter Beaven advocated addressing water ownership.
Without ownership, he said government would say no one could charge for it. "We need to refine the discussion on water, we have to stop saying no one owns water, and start saying everyone owns water."
By including local communities and iwi in water ownership, it would ensure they made decisions about how to use it.
"If we're not using water to add value... then we are giving a valuable resource away."
He cited the nine consents within Hawke's Bay which covered a total 40 million cubic metres of water bottled annually, and said if the region were paid a cent per litre it would be a $40 million injection into the economy.
Having a lot of water "made us a bit lazy", he said, with only 2 per cent of what fell being allocated.
"It's an important task for all regional councils to manage this precious resource, it's our job to manage the quality and quantity of the water."
However, he said the regulatory framework to do that was "woefully inadequate".
While Napier MP Stuart Nash said he agreed with Mr Beaven, he would charge 2 cents a litre.
"If someone is making an economic gain out of our water they should be paying for it."
Putting the issue in a global context, internationally 500,000 people died a year from contaminated water he said.
"You know what we do with our water? We give it away for free."
Dr Adele White explained the value of water to Ngati Kahungunu iwi, citing cultural and economic research, their property water rights, and how their interest in water space had increased over the years.
She said iwi saw water access across all spectrums, economic, social and cultural, and it was up to users to choose how to use it.
Chris Kennan from horticulture New Zealand put the issue in a wider context, and spoke of the challenges dealt with around the country and worrying projections around water scarcity for the future.
Mr Kennan said when considering the value of water, it had to be looked at in terms of its impact on other values such as food.
"I'm sick of just talking about the commercial value of it," he said. "If you don't think communities have other values for it you are wrong."
He also said if water was to be priced or allocated, that needed to be measured.
The floor was also opened to the public, with statements and questions answered by panellists.
