Water Capture FAQ

Expert answers to all your questions about gray water, rain water, and water recycling systems to reduce your water bill, survive drought, and save the planet.

Why think about water harvesting?

Water harvesting is an eco-friendly and cost-effective method to collect extra water to reduce municipal water consumption and bills. As we know, with the increase in population, the fresh water needs increase, and in the future, the groundwater supply in many areas will likely no longer meet the needs of the population. Water harvesting increases the availability of water by adopting collection and recycling methods mapped to the various water-usage needs in your home.

What does the future of water look like?

Scarcity: Due to global warming, rain and snowfall patterns around the world are changing dramatically. In many regions, such as the Southwestern United States, the climate will become drier, while other areas may experience more pronounced dry-wet seasonality. In California, drought continues unabated. According to the latest US Drought Monitor Report, 46.77% of the state is currently in “exceptional drought”. The “exceptional drought” category increased from 32.21% at the beginning of 2015. At a time where reservoirs across the country should be filling up from snow-melt, reservoir levels are actually dropping. Researchers are finding no midwinter snow in many areas, for the first time in the 70-year history of formal precipitation surveying. Another study published in the journal Nature says that over a quarter of the world’s population could live in a state of permanent drought by 2050 if the goals of the Paris climate agreement are not met. Unpredictable and sudden changes in environmental and ecological systems due to global warming will directly affecting the availability of freshwater.

High Costs: There will be increased demand for fresh water, due to population and wealth growth. At the same time, supplies may decrease from drought. Water companies will increase their prices to provide water to the population. Many water systems will resort to rationing or risk running out of reserves. In many California cities, water prices have increased 120% in the last 5 years. For a view of the near-future, Denmark has some of the most expensive water prices in the world; there, it costs $2,115 U.S.D. per 200 cubic meters. By comparison, the same amount of water in the United States could cost less than half that much.

Solutions: This situation will lead water companies and people towards adaptation of eco-friendly and cost-effective ways to harvest, recycle, and use less water. Various forms of water harvesting will be key for homeowners who want to to sustain or overcome the consequences of global warming, and protect themselves from droughts and increasing water prices.

What is rainwater harvesting?

Rainwater harvesting is a method to capture, store, filter, and use the rainfall on your property. Common rainwater uses include water for gardens, livestock, irrigation, domestic use with proper treatment, indoor heating for houses, etc. The harvested water can also be used as drinking water, set in longer-term storage, or for other purposes such as groundwater recharge.

How do rainwater collection systems work?

Rainwater harvesting system captures rainwater by directing it from large surfaces (e.g. roofs) to an underground or above ground holding tank. The harvested rainwater is filtered and then pumped directly to water-using appliances or to a header tank. Other surfaces by which rainwater can be easily collected includes parking lots, roadways and driveways, depending on the intended use.

How can rain water be used?

Properly treated and filtered rainwater can be used for any application well water or municipal water can. Common uses include: flushing toilets, showers, sinks, washing machines, washing vehicles, fire protection, gardening and irrigation.

What is required for rainwater filtration and treatment?

Filtration system for rain water varies according to the intended use of rainwater. If rainwater is going to be used for drinking or food-related purposes, special filters are required to remove harmful substances like bacteria and viruses. Polypropylene & ceramic cartridge type filters, activated carbon filters and micro/ultra filtration membrane filters are mostly used for filtration of rainwater to make it drinkable. Use of rainwater for other “graywater safe” activities like washing cars, flushing toilets and gardening usually does not require these filtration systems except a simpler filter for removing sediments.

How much rain water could I collect off of the roof of my house?

For calculating how much rain water you can collect from the house roof, you need to know your annual average precipitation in your area and the square footage of your roof top.

The amount of rainfall that you can collect from your roof can be calculated with the following formula:

1″ of rain x 1 sq. ft. = 0.623 gallons

The average residential roof size in the United States is about 1,700 square feet, although there are many larger homes (think, your standard “McMansion”) with roofs twice as large.

For example, if your area in California receives 50-inch average annual rainfall, then with an average roof size of 1,700 square feet a resident could collect about 52,955 gallons of rain water annually.

50″ of rain x 1,700 sq. ft. = 52,955 gallons

What is gray water?

Gray water can be described as wastewater which is produced from sources like bathroom, kitchen and laundry. Wastewater from toilets is not included.

How do gray water systems work?

This system involves three basic steps: Collecting the gray water, storing and treating the gray water, and then using the gray water. With a slightly modified plumbing set up, gray water can be collected from the sinks, baths or washing machines into a tank or storage container. Generally speaking, collected gray water should be used quickly, within 24 hours, to avoid the risk of bacterial build up or the heavy treatments necessary to prevent it. Mild chemicals like chlorine or iodine can be added to ensure against this. The storage containers are generally connected to a system by which gray water can be diverted to flush toilets, or, more simply, to irrigate a lawn or garden. The gray water can be moved either by gravity or by using electric pumps.

Where can gray water be used?

With proper treatment, gray water can be used for many applications, though the most common is free, eco-friendly irrigation for lawns and gardens.

Is gray water safe?

With proper treatment, gray water can be made safe for most uses. Gray water is easily suitable for toilet flushing and irrigating lawns, trees and ornamentals. Toilet flushing can use considerable amounts of gray water, as it normally accounts for up to 50% of indoor water use. Low-treatment gray water is not a problem if it is used to flush toilets, because the water goes into the sewer or septic system where it would have gone had it not been reused.

What other types of water capture are there?

Finding alternative, eco-friendly, and diversified water sources will be crucial in our drier, less-predictable future. Techniques can include digging wells or reservoir ponds, sculpting and terracing landscapes to maximize rainwater efficiency, or even collecting dew and fog with a set of techniques known as “atmospheric water generation”. An assessment of your needs, climate, and budget are necessary for determining the proper water harvesting methods for you.

Will water harvesting lower my water bill?

Yes, water harvesting will definitely lower your water bill as it is an eco-friendly and cost-effective method. Water harvesting and reuse of wastewater will reduce the municipal water consumption up-to 50% and it will lead to lowering your water bills.

How much does a rain tank or water tank cost?

Rainwater tanks start as low as $70 for a small, freestanding model without pump or extras, and range up to $2,000 for arge, custom-built models. Costs vary depending on the size, material, finish and strength of the tank.