In one of our recent projects, we installed a rainwater harvesting system that captures 100% of the roofs’ runoff water. The water is captured through gutters and then routed into a 16,000 gallon tank. For this purpose we installed a “trunk line” all the way around the home’s perimeter. All the downspouts of the gutter system “feed” into this trunk line which is connected to the tank. The water is pushed into the tank by gravity and then pumped out when needed. One important aspect of the system is the pre-filtering system, on this project we used a product called “Gutter Foam”. You can find details about their product at http://gutterfoam.com. You can see in the picture that the foam piece is wedged in the gutter and prevents any debris from entering the system.

The tank is a galvalume tank with interior liner set on a sand & gravel base. It has a backup line from the city water meter in case the water level ever drops too low. At this point the backup kicks in and fills the tank to minimum level with city water. Water is pumped out of the tank with a Grundfos pump and filtered through a UV-filtration system. That way the water will not carry and “foul” odor, especially if it is used for toilets or exterior water faucets. In this home the rainwater harvesting system supplies 100% of the irrigation water and 100% of the water for all toilets and the washing machine. This dramatically reduces the use of city water and also helps with managing drainage around the homes’ perimeter.