Rain Harvesting----Rain Water INFO
First Flush is a must when looking to use your stored rain water. The simple diagram above helps explain visually the importance and parts of a first flush. Don't forget to add a first flush to rain collection system!
Learn More About Rainwater Harvesting, Storage and Usage
In arid areas where rainfall is light and drought is common, large storage tanks can be expensive but well worth the money. If rain falls often in your region, you might consider a smaller system like a rain barrel to handle your watering needs during the occasional dry spell.
Make sure that your rainwater collection devices are covered and tightly sealed. This helps minimize mosquito populations and prevent them from becoming a drowning hazard to small children. Tightly secure your storage device to the ground so that it won't easily fall over. One gallon of water weighs over 8 pounds, so even a half-full 55-gallon drum can be a crushing hazard.
Rainwater is relatively free of chemicals and toxins when it leaves the clouds, however dust, leaves, bird droppings or bugs from your roof can easily be washed into your conveyance system (the gutters and downspouts). Keeping your storage tank free of this debris is critical if you want to maximize water pressure and the longevity of the rainwater system.
A simple metal mesh screen is ideal for filtering out larger debris, and a second fine screen at the mouth of the storage tank will help keep small critters out of your watering supply. Be sure that the filtering screens are readily accessible to make cleaning and maintenance easy.
Once you have filtered the water in your rainwater storage tank, you can retrieve it with a manual hand pump, electric pump or through a spigot. Most of the rainwater storage tanks available to homeowners come equipped with a standard garden spigot near the bottom of the tank where you can easily hook up a garden hose.
For larger irrigation systems or systems where most water is stored below grade, a pump is generally required to get the water out of the storage tank. There are two types, manual and electrical. Hand pumps require manual energy and aren’t as convenient as electrical pumps which cost more, but will enable you to water plants in a raised or hanging location with ease.
With a rainwater harvesting system, the water must be moved from the collection system to the filtration and storage tank before you can use it. For standard roof-collecting systems, gutters are the first part of the conveyance stage. The most common place to tap into a conventional gutter system is at the downspouts. From there the water can be diverted directly into a rain barrel or storage container.
You can cut the existing downspout and attach it directly to a filtering device, or you can install a downspout diverter to direct excess water down and away from your home when the rain barrel is full.
How much rainwater falls on your roof?
Each inch of rainfall drops 1,240 gallons on a 2000 square foot roof. To approximate the amount of rainwater falling on your roof, multiply the square footage of your roof footprint (including porches and garage) by .62 to get your gallons per inch of rain. Tip: if you don't know the square footage of your roof footprint, substitute your house square footage.
How much rainwater can you collect from your roof?
It depends mainly on the annual rainfall in your area, but also on the "runoff efficiency" of your roof. A conservative estimate would be 85% efficiency due to evaporation, splashing, and roof surface smoothness. So a realistic collection amount from that inch of water on a 2000 square foot roof is 1,054 gallons. Multiply the square footage of your roof by .527 to get a conservative estimate of your collection potential.
How can you use less water on your yard?
Water used for foundation plantings and gardens can be cut in half by using drip irrigation and mulch instead of sprinklers or sprayers. St. Augustine turf needs about an inch of water a week to stay green. Several varieties of Bermuda need only half that amount. Buffalo grass needs almost no supplemental watering once established, but it needs a lot of sun. Consider replacing your sunnier areas of St. Augustine with Buffalo grass, and creating mulched areas in the shadiest spots planted with native or adapted low water use plants. You can probably reduce your turf water use by half or better.
Why does grass look so much greener after a rain?
Rain clouds form in the sky when water vapor in the atmosphere cools and forms droplets. These droplets also contain dissolved nitrogen that comes from the air. (Nitrogen is the main active ingredient in commercial lawn fertilizer). Rainwater, whether it comes as rainfall or from a rainwater storage tank, greens up your grass with free, natural fertilizer. And you will be "greener" since this free fertilizer isn't made from hydrocarbons.
How much water do you use in your house?
Nationwide, we use about 150 gallons per day per person, which includes outdoor use. Indoors, we use about 70 gallons per day per person. Of that, less than 5% is used for drinking and cooking. Most is used for washing dishes and clothes, flushing toilets and bathing. It takes 2 gallons to brush your teeth, 2 to 7 gallons to flush a toilet, and 25 to 50 gallons to take a shower. If you have low-flow toilets and faucets, usage might drop to about 60 gallons per person. By using water-efficient appliances and water-conserving practices, you can achieve a daily per-person usage lower than 50 gallons per person.
What are the components of a rain harvesting system?
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