Your name saw this post on The ActiveRain Real Estate Network and thought it might be of interest to you. Please see the link below to review the post.

How does water catchment work in Haiku Maui Hawaii?
How does water catchment work in Haiku Maui Hawaii?
In some parts of Maui and the other Hawaiian islands, there is no county water service, no water lines.  The nature of the terrain and I suppose the low population density makes it unfeasible for the development of new lines.  There are no plans to provide this basic utility.
In rainier areas, such as Haiku or Hana and Nahiku it's not unusual to have catchment water as your primary household water source.  There's plenty of rainfall to supply all the water you need, provided you have enough storage capacity.  You will be able to get a building permit for your Maui home if you use water catchment.
How big a tank you'll build will depend on your home size, and the requirements of the Maui County building department.  A 5-10,000 gallon tank might be sufficient, but to get a permitted tank you'll more likely have to go bigger, like 12-20,000 gallons.  The extra water supply is for your benefit in the event of a structure fire.
The basic requirements:
a roof, preferably metal - Metal surfaces won't degrade and create particles or toxins in your water.  Avoid composition shingle type material if ... more

__________________________________________________
Are you on The Rain? Grow Your Network!