Resolved Water Issues

Wondering if this could be a solution for us - opinions very welcome =)

Wow - the water issue ... we've put some extra money on your water rates to cover the rescuing of stressed trees in our garden. And feeling guilty because although we aren't on any restrictions, it's drinking water we are using. No trees have died but the small leaved tamarind lost 70% of its leaves before we got to it.

I have been thinking of a way to use naturally occurring water on our land. A rain tank is not very useful while it's not raining. However, a combination of a bore, a small windmill to drive the pump, and a tank for the water to go in seems like a good, if very expensive, idea.

My aim would be to have the windmill drive the pump to get water from the bore and fill the tank which would be at the top of our garden slope. Then open a reticulation system and allow gravity to water the garden. There is not high pressure needed, not electricity needed, just maintenance on the system as a whole.

Wondering if I have a good idea here? Cheers - Cate =))