Rainwater is directly harvested for domestic (household) consumption in over 100 countries, yet a massive amount of rainwater that could be used for watering plants and other purposes goes to waste every year. For instance, a 930 square- foot roof intercepting 3.28 feet of rainfall per year will shed, on aver- age, 71.2 gallons of water per day. This amount is roughly 75% of a typical North American person's domestic consumption. Just think about how much water would be harvested if every person in the United States who lives in a house collected the rainwater coming off of their roofs.