Austin Greenbuilder Program Rainwater harvesting section of sustainable building sourcebook describes the potential for collecting and using rainwater as a water supply. The Austin area receives an average of 32 inches of rain per year. A 2000 square foot area can capture 36,000 gallons of water, which would match up 100 gallons per day in water demand. This is a significant amount of water toward the needs of a waterconserving home.The quality of rainwater can vary with proximity to highly polluting sources. However, in general, the quality is very good. The softness of rainwater is valued for its cleaning abilities and benign effects on waterusing equipment. As an irrigation source, its acidity is helpful in the high PH soils of our region and, as one would expect, is the best water for plants. Rainwater harvesting systems designed to fill all the water needs of a home can be similar in cost to the expense of putting in a well. Operating costs for a rainwater system can be less. Rainwater collection systems designed to supplement the water needs of a home already on the city system for irrigation purposes can be costly. The primary expense is in the storage tank cistern. In our area, the cistern size for irrigation can be large due to the high temperatures and extended dry periods in the summer. If the system is not counted upon as the only source of irrigating water, building as large a cistern as one can afford is often the measuring gauge for cistern size.

Address: Sustainable Sources 108 Royal Way #1004 Austin, TX 78737 USA
Website: http://www.greenbuilder.com/sourcebook/RainwaterGuide1.html