Watch the video on Rain Barrels.
Municipal water costs are rising, and in many areas of the county, the municipal water supply is under strain. Systematically collecting rainwater for home use can help take pressure off the municipal water supply and also reduce the amount of homeowners' monthly water bills.
The most common way to collect rainwater is to "catch" water that falls on the home's roof and direct it, usually via gutters and downspouts, into a rain barrel or a cistern for later use. For every inch of rain that falls on a catchment area of 1,000 sq. ft., you can collect about 600 gallons of rainwater. For example, a home with outside dimensions of 27 x 37 feet with overhanging eaves of 1.5 feet at each wall has a total catchment area of 1,200 sq. ft. [(27 +3) x (37 + 3) = 1,200]. So, for every inch of rain that falls on this roof, the homeowner can potentially collect 720 gallons [1.2 x 600 = 720] of water. Note that rainwater catchment systems typically are 70 to 90% efficient; all systems lose some of the rainwater because of spillage, wind, evaporation, or other reasons.
A common and easy-to-implement use for collected rainwater is watering outdoor landscaping. Rainwater is naturally good for plants. It doesn't contain the minerals, chlorine, fluoride, and other chemicals that municipal water does, and you can use it directly from your rain barrel or cistern without special filtering. The simplest way to collect rain for landscape watering is to put a rain barrel under one of the home's downspouts. A variety of rain barrel types and sizes are readily available for home use, ranging from 55 to 80 gallons. To collect more water, connect several rain barrels together near the bottom using PVC pipes or hose. You can use the water directly from the barrels with a spigot or hose, or install a small pump in one of the barrels to pump water to your landscape. Even greater amounts of water can be collected by using gravity to carry water from all the home's gutters to a larger cistern for longer-term storage. These systems almost always involve a water treatment system and pumping the water back to the landscaping.
Collected rainwater can also be used for drinking, but first it requires special filtration. The most simple and inexpensive type is a microfiltration process that uses gravel, sand, and charcoal. Two other more expensive treatments are UV sterilization and ozonation, which cost about $1,000 each. If you're going to collect rainwater for filtration and drinking, it's important to understand that many areas require the drinking water filtration system to be certified and the water to be tested regularly.
Health and safety considerations
When using the home's roof as the rainwater catchment area, carefully select the roofing materials. Stainless steel or galvanized steel with a baked-on enamel, lead-free finish are the best, because they are smooth, impervious, and not treated with any chemicals that will leach into the water. Poor choices include organic roofing materials such as wood shakes, clay tiles, or concrete materials because they'll support algae and mold growth, and wood shakes treated with preservatives can contaminate the water. Other poor choices include asphalt shingles, rolled roofing, and porous or rough materials, because they'll hold more particulates such as bird droppings and heavy metals. Porous materials also absorb more rainwater, reducing the collection efficiency.
In addition to roofing materials, consider the gutters, downspouts, and piping materials. Avoid lead-based solder in all metal-to-metal connections. Opt for piping made of roll or channel-formed copper, aluminum, stainless steel, galvanized steel, or PVC to limit water contamination.
Follow these additional guidelines for safe collection of rainwater.
- Check rainwater quality. Before you decide to begin collecting rainwater for home use, check with your local government about possible environmental contamination. If you live in an area that produces heavy industrial pollution, your rainwater itself may be contaminated, and you may decide not to use it.
- Locate rain barrels on level, stable ground. At maximum capacity, rain barrels will weigh quite a bit and will tip more easily on uneven ground.
- Cover rain barrel openings. A tight-fitting lid, most importantly, will keep children and small animals from accidentally drowning. It also will stop algae from growing, minimize accumulation of leaves and other contaminants, and prevent your rain barrels from becoming a mosquito breeding ground.
- Use an overflow device. Make sure your collection system has an overflow device to direct excess water away from the home's foundation when the rain barrels or cistern reach capacity. An overflow device can be as simple as allowing excess water to continue through the downspouts into the municipal storm sewer.
- Monitor water collection. Check rain barrels regularly to make sure intakes and overflows aren't blocked with leaves or other debris that could limit collection or delivery.
To learn more about Rain Barrels, visit:
www.rainbarrelguide.com/
dnr.metrokc.gov/wlr/pi/rainbarrels.htm
dnr.metrokc.gov/wlr/pi/pdf/Rainwater-Harvesting.pdf
dnr.metrokc.gov/wlr/pi/pdf/cistern-water-saving.pdf
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