Why not install your own well?

[Carey]

There are more people adding wells, esp. on the Kona side and in coastal areas, but it is more $ to install than many catchments, and can have brackish infusion (most of the fresh water on island is sitting in a lens shaped pool floating on top of sea water...the closer to the edge on the 'lens' the thinner the layer of fresh & the more likely to draw a brackish mix. This is also a reason not to keep drilling, esp in a coastal area, as you may go into the salt water base.) The deepest private water well on earth is on this island, at Pu'u Wa'awa'a, at around 4,000'.
There is a well driller on the forum that can give you much more information.