Social Design Gris Water Saving System by Carlos Alberto Vasquez Decrease of water resources is a world wide problem these days. It’s crazy that we still use drinking water to flush the toilet! Gris is an incredibly cost effective water-saving-system which can collect all the water you use during a shower. You can reuse this collected greywater for flushing the toilet, cleaning the house and for certain washing activities. This way you can save at least 72 liter water/person/day in an average household which means at least 3.5 billion liter saved water per day in such an 50 million habitant country like Colombia.