Frequently Asked Questions
How much water can harvesting save?
Indoor water use varies primarily as a function of the number of occupants in a household. Typical water use ranges from 55 to 75 gallons per person per day. For a family of 4, this works out to a range of approximately 200-300 gallons per day, or 1,400 to 2,000 gallons per week.
Outdoor water use varies widely, primarily based on usage type or irrigation watering patterns. See below for information on potential uses for collected rainwater.
The chart below provides examples of typical outdoor water use for irrigation watering for varying landscape areas.
|Irrigated Area, Square Feet||
Recommended Weekly Water Usage
|2,000 sq. ft.||1,200 gallons|
|4,000 sq. ft.||2,500 gallons|
|8,000 sq. ft.||5,000 gallons|
|12,000 sq. ft.||7,400 gallons|
|15,000 sq. ft.||9,300 gallons|
|Half-acre (21,780 sq. ft.)||13,500 gallons|
|8,000 sq. ft. Acre (43,560 sq. ft.)||27,000 gallons|
Without chemical treatment or special filtration, harvested rainwater typically does not meet State and Federal drinking water standards and as such is not suitable for human contact applications. Subject to regulatory stipulations, however, harvested rainwater may be suitable for treatment to allow for potable usage. Contact your local Department of Health, or Rainwater Recovery Inc. for further information.
Storage requirements depend on usage type and requirements. For irrigation applications, system size is determined based on area of intended irrigation and the desired interval between natural precipitation events the systems is designed to span.
Periodic cleaning of the filtering device and material is required at intervals that vary as a function of the type and size of the system, the proximity to trees and leaves to collected roof areas and the type and effectiveness of downspout screening materials. Inspection and maintenance as required should be performed at least twice annually.