Don't use rain runoff from the roof. Use a capsulated tank and have water trucked in or use a pump to extract well water. Those who can afford it will find ample groundwater within Puna. Eventually the County will feel guilty enough for allowing these unserviced lots to be created by unscrupulous developers to provide public water to these areas. This is the unintended consequence of not providing a basic need in the first place. The cost is inconsequential when solar energy technology for pump power and the availability of underground water table is present. It is possible and doable. IMO.