Tarheel - in the UK many of us have 'water butts' (these are often purpose-made plastic containers you can buy from garden centres or DIY stores) that you use to collect rainwater. We have several in different parts of the garden, to collect water from the house roof, the greenhouse, shed, etc. You can get a simple gizmo that fits into the rainwater downpipe and delivers the water into a butt standing nearby, and when the butt is full, the water continues down into the drains or soakaway. So the butt won't overflow and flood your garden during wet weather. The butts have a tap near the bottom so you can fill your watering can, etc. from them.

Most people use the water thus collected to water the plants in their garden during dry weather, to avoid using the mains water (which many of us have to pay for by the litre, as it's often metered).

I guess there may be some folk who use it for other purposes such as washing but I don't know of any personally. However we do have a near neighbour who uses their bathwater to water their garden (they have rigged up some sort of piping system to divert the bathwater into a butt during droughts).

I guess if the UK water companies don't get their act together and build more reservoirs to allow for the thousands of new homes being built (especially in the south-east of England), we might all end up depending on the water we collect ourselves to survive :-(