Catching rainwater for later use has been done for centuries, but many of us don’t do it in this modern day and age. Having free access to running water has made it unnecessary to go through the trouble, but that doesn’t mean that there aren’t any benefits to invest time and effort into it. For one thing, fresh water supply is not a guarantee. While there aren’t any current problems in this country, no one knows what the future might bring.
Some choose to get their own water catchment system to supplement a well. A simple system that supplies water for flushing toilets, watering crops and doing laundry can easily be installed, but if the water will be used for cooking, drinking and showering, a filtration system will be needed.
You should make sure that the surface where the water is collected is clean; you don’t want a roof with flaking paint or covered in bird droppings to be the source of your drinking water.