rain water

I was visiting some friends the other day and found out they had a big underground storage tank to collect rain water from the roof. It is apparently pretty rare although I was told it is quite common in some parts of the world. Probably those parts where it rains a lot and people have plenty of water to begin with, as in the UK and parts of Northern Europe.

It has always struck me as ironic that places like California, parts of Australia and even South Africa sell bottled drinking water and juices. In case you did not know, these are largely desert areas. So why are they selling water? And why do people find it so exotic and attractive to buy water from dry places?

In any case, my friends had a very nice set-up, where the rain water was used automatically for clothes washing and for flushing toilets. I could not tell and if they hadn´t told me I would never have noticed. They have a dual system, and when the rain water runs low, they can switch to the utility by flipping a switch.

Their main reason for doing this was to save their equipment. Where they live the water is quite hard, or high in calcium. Calcium deposits ruin things and appliances need frequent treatment to keep them in good working order. Where we live the water is quite soft, although even I noticed that rain water is better for washing clothes. Apparently, when water is hard, the difference is even more pronounced. Plus you need a water treatment or the machine will die a premature death.

So, it can be done. The question is why doesn´t everyone do it? Why do we think of desalination and other excessively wasteful and expensive options when everyone could just collect their own rain-water? Is it because of the way one ends up paying for things? I.e. big upfront versus monthly? Or maybe, like so many other things, water is just too cheap here in California?