Any wash water that has been used in the home, except water from toilets, is called grey water. Shower, sink, and laundry water comprise 50-80% of residential “waste” water. This may be reused for other purposes, especially landscape irrigation.

NB : Kitchen Sink water is also classified as “dark grey water” and is only suitable for harvesting if the correct system is put in place. It is cautioned against harvesting kitchen sink water due to blood and meaty fats present.