The type of water system you choose will depend on the quality of the land and the location on the 53.5 acres you decide to build on. Reverse Osmosis systems are great here because we never run out of seawater, but they are pricey and must be maintained meticulously. I personally think the initial investment in a good RO system is worth it's weight in gold. You can live without a lot of things but water is not one of them.
You can also do a combination of rain catchment and a well. A well is ok if you can find good water and there is occaisional maintenance that needs to be done with that as well. They do wells differently here than in the states and about once every year or so you will need to dig out the silt that filters in or it will start stinking from decaying plant materials. You will know when it's time because you will smell it when you take a shower. LOL Also using one of those floating pool chlorinators with chlorine tablets works well. This water is not usually drinkable though so you will need to have access to bottled water or even a small under-the-counter R.O. system for your drinking and cooking water.
When we go through a dry spell the well may also get low and start to smell. This is when you utilize your rain catchment storage.
Rainwater is great. If you have a house with a roof large enough to collect huge amounts each time it rains, with sufficient storage capacity, you may be able to use rain water as your primary source and the well as backup.
Keep in mind all three systems require electricity for a pump to run them.
The best way to plan for your infrastructure is to imagine a worst case scenario. Don't forget any details. If you do, you will be reminded of them the first time a hurricane (worst-case-scenario)hits. LOL
Been there...done that!
There is a good website for off-the-grid products and supplies. It used to be called Jade Mountain. It has now merged with a company called Real Goods and can be found at: http://www.realgoods.com/renew/
They have everything you could possibly need to be self sustaining.
I have a schematic drawing for a household rain catchment system. If anyone would like it just email me at [email protected]
Cheers! (as Wendy says