Rainwater catchment, collection & harvesting is the capture and storage of rainwater for landscape irrigation, agriculture as well as potable and nonpotable indoor use. Collected & harvested rainwater can be particularly useful when no other source of water supply is available, or if the available supply is inadequate or of poor quality.
Rainwater has long been valued for its purity and softness. It is slightly acidic and is free from disinfectant byproducts, (chemicals) salts, minerals and other natural and man-made contaminants. Additionally, rainwater collection & harvesting is valued as a water conservation practice which reduces demand on more traditional water supply sources like municipal and private water well systems.
The capacity of a rainwater collection & harvesting system depends on the amount of rainfall, size of collection area, rainwater storage capacity, and the household’s level of demand for water. The Boerne and Fair Oaks Ranch TX area receives an average of 32 inches of rain per year. A 2000 square foot area can capture 36,000 gallons of water. This is a significant amount of water toward the needs of a water-conserving home.
A complete rainwater collection & harvesting system for a typical single-family home will generally cost somewhat less than drilling a water well. However, the utility and water treatment costs are much less. The single largest cost in a rainwater collection & harvesting system is the rainwater storage tank. As expected, the cost of a rainwater storage tank or cistern depends on its size and construction material.
Other components such as gutters, downspouts, roof washers, water booster pumps, and water pressure tanks will add to the cost of the rainwater system. If the intended use of the rainwater catchment system is to collect water for drinking, costs for disinfection must be added to the total cost of the rainwater catchment system.