Russell Baylis has been drilling wells all his life but he still fizzes about Hawke's Bay aquifers.
He took local leaders on his 15th monthly tour yesterday, explaining what is known about the underground rivers.
He doesn't charge for the tours, saying more people needed to realise what an aqua bonanza the region had.
"We have the best aquifer in New Zealand by far and it is right here under our feet," he said.
The amount of land it flowed under, relative to the size of its catchment, meant it was easily being under utilised.
He likened the many contained aquifers to veins of a body or underground hosepipes, carrying water long distances securely.
Outside Hawke's Bay Prison at Mangaroa he pointed out a bore to an aquifer that flowed under the Tukituki River and Cape Kidnappers Golf Course on its way out to sea.
He was certain of its course because of matching gravels found when drilling, but where other aquifers came from or went to required "a bit of guess work".
He said Hawke's Bay Regional Council needed to do more exploratory drilling because there was a lot more water underground but it needed to be found and qualified/quantified to "open up the resource to everyone".
The tour group was a mix of private and public sector leaders, invited by Napier MP Stuart Nash.
"I think it is very important the region's leaders understand what is happening," he said.
"I'd like them to put pressure on the Regional Council so it can do some research around this. The level of data and research we are doing is not sufficient to provide us with informed decisions on how we use our water."