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.