Rainwater Collection is Gaining Ground
The collection of rainwater is quickly growing in popularity across the country. A typical household can significantly benefit from this natural commodity in so many different ways.
Rainwater collection in the U.S. can certainly trace its roots to its earliest times. In arid parts of the country especially, it's easy to imagine early settlers using various methods to collect rainwater as a primary source of drinkable water and crop irrigation. As water storage and delivery systems modernized, rainwater collection became less and less of a necessity in almost every part of our country. The practice never completely disappeared, however. Rainwater collection has always been, and will continue to be a necessity in areas where other freshwater sources such as rivers, lakes, ponds and wells are scarce, inadequate, or impractical.
The most common rainwater catchment area available to most people is a household roof. During the collection and storage processes, rainwater can be contaminated from roof pollutants, airborne dust, insects, and other debris. This can be minimized, however, by using simple screens and filters where rainwater enters and exits a storage tank. A rain barrel is only one of many types of rainwater storage tanks. Much larger holding tanks, both above and below ground level, and even converted 55 gallon drums and wine barrels are all commonly used. Depending on the size of your roof and the amount of rainfall in your area, you can collect a substantial amount of rainwater. For example, one inch of rain falling on a 1,000 square foot roof can generate about 500 gallons of captured rainwater!
Some water supplies contain added chemicals such as fluoride and chlorine, or naturally dissolved salts and minerals from the soil. Rainwater is a naturally soft water devoid of minerals and chemicals. In fact, the quality of collected rainwater is generally better than many
water sources. That makes it a very good source for drinkable water for pets and livestock, and for irrigating landscapes, gardens and crops.
For individuals choosing to live “off the grid”, rainwater collection is an important aspect of becoming self-reliant. For individuals interested in the “green” aspect of rainwater collection, this practice represents an environmentally friendly utilization of our natural resources. Another obvious motivation for many is the fact that harvesting rainwater saves money. Individuals can commonly utilize enough stored rainwater over a period of time to significantly decrease their usage of municipal supplies which results in a positive impact on their water bill.
As more people become aware of the benefits of rainwater collection, more systems are being installed on new and existing homes and other structures. A variety of different groups, organizations and agencies are currently and actively promoting these system installations wherever practical. In a growing number of cities such as Santa Fe, New Mexico, and in the U.S. Virgin Islands, rainwater catchment systems are mandatory for new dwelling construction. More and more states like Texas, Ohio and Oklahoma are passing legislation which promotes projects for rainwater catchment among other water saving techniques.
Unfortunately, the U.S. Is not a leader in the field of rainwater catchment research, development and education. Rainwater harvesting systems are being installed in a number of schools in Israel for the purpose of educating schoolchildren about water conservation principles. Many countries already have extensive systems in place to take advantage of this relatively low cost source of potable and non-potable water. About 50% of the households in Queensland, Australia harvest rainwater. Gansu Province in China and semi-arid Northeast Brazil may have the largest rooftop rainwater harvesting projects currently ongoing.
One of the most beneficial and efficient uses of stored rainwater is the irrigation of crops, gardens, and landscapes. Utilizing a drip irrigation system can help in conserving the stored rainwater. A typical gravity feed drip irr system consists of rainwater stored in one or more holding tanks, and utilizing the natural water pressure created by gravity, the water is directed through drip irrigation tubing and emitters which distributes the water to the plants. Elevation creates water pressure. For example, for every 10 foot of elevation you can gain you will create 4.3 psi. The closer you can get to an adequate pressure the better your distribution uniformity will be. That being said, we have identified the following products that can be adapted to very low pressure gravity systems.
Drip emitters, specifically non-pressure compensating or those with turbulent flow technology, can operate at very low water pressures. Micro In-Line Shutoff Valves are often used when the water supply is considered “dirty”, referring to water not thoroughly filtered and not from a municipal water supply. These valves have a larger orifice than standard drippers and are much less susceptible to clogging. Quarter inch drip line tubing and drip tape can be compatible with gravity feed systems as long as the water source is thoroughly filtered and can produce the water flow rate required by the system design. Drip Depot has been working on identifying products and developing kits to help overcome many of the systemic issues that are inherent in gravity systems. Many of our drip irrigation kits even though designed for pressurized systems, are also compatible with gravity systems.
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