DISCLAIMER: Harvesting rainwater is illegal in some places. If a permit can be obtained in the area you are trying to harvest rainwater, please do so before collecting and harvesting the water. Some locations do not allow you to harvest rainwater for potable use. You are solely responsible for your own health and safety consuming illegally harvested rainwater. It is not my responsibility nor will I be held liable for your actions.
Cisterns or water catchment systems are a great way to collect water for purposes other than drinking, personal hygiene, and showering. I personally do not use collected rainwater for anything except for watering outdoor decorative plants and landscaping.
There are filtration systems and methods that may make it safe to drink, but based on what is in the air and what materials it touches before it goes to the rainwater collection system, it is generally not safe for consumption or even showering. Now, this can depend on if you are catching it from a trickling waterfall in nature as opposed to rain falling from your rooftop.
Rainwater in most of the planet carries viruses, bacteria, parasites, and harmful chemicals that make it unsafe to drink or even use to wash yourself or brush your teeth. Boiling the water doesn’t eliminate the harmful chemicals. Don’t even use the water for plants that produce edible fruit or vegetables. I wouldn’t even use it to do laundry using a manual crank washer. Yes, some third world countries wash their clothes in rivers and streams that contain harmful chemicals, viruses, bacteria, and parasites, but I don’t like taking unnecessary risks.
Here are some example uses for rainwater that is collected in a cistern or catchment:
- Watering the lawn – I don’t have lawn because it uses too much water
- Watering the landscaping plants
- Washing items that you don’t use to consume or don’t use on your body (like driveways and cars)
- Toilet flushing – remember when the power goes out for a prolonged period, there will be no tap water or water for the toilets
Can I make it potable?
Yes, you can with a hefty investment in a water processing and filtration system. It is very similar to what the public utility system uses, but in a smaller package. Professional installers can even tap this into your home, and have a switch installed to go from public water to stored water. There is a significant cost associated to this type of system, but if money is no object, and you can have a water catchment system and storage which can be a great option for potable water.
