- Q: Are we running out of water?
- A: The world is incurring a vast water deficit. The recent water deficit is the result of a combination of many things: Demand has tripled over the last half century, causing falling water tables, disappearing lakes, and even rivers running dry. Unless steps are taken, failing infrastructures will result in a 40% deficit in water availability to meet demand in 20 years. According to the American Groundwater Trust, 3.3 billion people worldwide will experience water scarcity by 2025.
- Q: What is the minimum amount of rainfall necessary to provide credible residential rainwater harvesting application for homeowners?
- A: Annual rainfall must be a minimum of 5 - 7 inches to yield results.
- Q: What is the national average of water usage per home/person?
- A: The average American uses about 90 gallons per day in the home and each American household uses 107,000 gallons of water annually.
- Q: What is the national average of household water usage for residential irrigation?
- A: 50 to 70% of available fresh water is used for residential irrigation.
- Q: What is the national average cost of water per year/household?
- A: The national average cost of water is $2.00 per thousand gallons or about $474 per year. Water is our most precious and rapidly shrinking resource. Because it is grossly undervalued, its cost is predicted to more than triple over the next ten years. These estimated cost increases include infrastructure rebuild.
- Q: What is average national square footage of residential roof tops to be used to catch rainfall?
- A: The average USA roof top approximates 1750 square feet.
- Q: What is the formula for determining the number of gallons of rainwater per square feet of roof space required for its conversion into harvested water?
- A: The formula is: .623 X square feet of roof space X annual inches of rainfall = amount of water reclamation per year.
- Q: Which cities have advanced forward in providing incentives/rebates to homeowners for installing water catchments?
- A: These US cities have provided or are working towards incentives/rebates to homeowners for installing water catchments:
- Raleigh, NC
- Atlanta, GA
- Santa Fe , NM
- Chino Valley, AZ
- Tucson, AZ
- Albuquerque, NM
- Santa Monica, CA (in process)
- Others in process
- Q: What are comparative analysis of water drip versus a sprinkler system?
- A: Many variables come into play in comparing each system. The consensus is that drip systems are 90-95% efficient in water usage, while sprinkler systems approximate 65-70% efficiency. A drip system uses about 25-35% less water than sprinkler system, resulting in less water usage than a sprinkler system and more saturation of the area watered. The two primary factors for this are:
- Water soaks into the soil before it is able to evaporate or run off.
- Water is applied only where needed, such as to plant roots rather than being sprayed everywhere.
- Q: What are inherent risks of existing old infrastructures, and what is the potential cost to taxpayers for re-construction of infrastructures to meet rising demand?
- A: To protect drinking water from contamination and the threat of further infrastructure deterioration, the NRDC recommends that cities replace/update pipes and water distribution systems in major cities. This need results in a funding gap of over $600 billion in cost to taxpayers. Residential water catchments can help, by reducing demand on aged infrastructure by using water where it falls, preventing runoffs and largely eliminating use of fresh drinking water for irrigation.
- Within Our Reach:A strong argument can be made that -- if there is national unity at all government levels within the US – a 3% penetration of converting homeowners to install water catchment systems, the following results would result in attaining water conservation, with conservative assumptions applied:
- There are approximately 100 million households in the USA. If only 3% of these homes on average installed rain catchment systems, with an average USA rainfall of 28.9 inches, these systems would conserve approximately 95 billion gallons of water annually.
City, state and federal action supporting such conversions by offering rebates and tax incentives, could go a long way toward shifting how we use our water, keeping our precious drinking water for drinking, cooking, and bathing, where purity is most important. - Figures used are conservative: USA precipitation in 2007 was below the long term mean, ranking as the 47th driest year on record. The average annual precipitation in 2007 was 28.9 inches (733mm) which is .03 inches (7mm) below the 20th century (1901-2000) average. Source: National Climate Data Center.
