Rain water harvesting is one of the easiest and most efficient means of reducing water consumption and waste. The quantity of water use varies dramatically by region and household, so stats about use and waste wouldn’t be incredibly meaningful. What you should instead realize it that toilets and garden hoses use the same quality tap water as kitchen sinks. While I personally am most concerned with water conservation and smart use natural resources, it is also worth noting that tap water has been clean and sterilized through a very expensive set of procedures in a very energy demand treatment facility. For us to send away the clean rain water that falls on our roofs and use drinking water for our toilets simply doesn’t make sense.
The image is a computer drawing of the Kingspan Water Integrated Rainwater Harvesting System. The basic premise is to eliminate the use of tap water in the home’s sewage system. Rain that falls on the roof is collected in the basin buried under the yard. This water is pumped into a smaller holding tank in the attic of the house which acts as the water tower to the home’s system. Then, when a toilet is flushed, gravity does the work. Obviously this system is more sophisticated than your average rain harvesting system. Even if you just store water coming off your roof in tanks and use it to water your lawn during dryer weeks, the reduced tap water use and reduced rainwater runoff will have a beneficial effect on the environment as a whole. Little things count.