Frequently Asked Questions
If your question is not answered below, feel free to contact us at info@SustainingRain.com
How much rain water is available in my area, and how much can I collect?
The Asheville area’s average annual rainfall is around 47 inches. A house with a 2000sq. ft. base can expect to collect about 58,000 gallons of water annually in this situation.
The formula for approximation is for every one inch of rain annual rain (AR), and every one square foot of collection area (CA - determined by the foot print of your house without regard to roof pitch or slope), you will collect .6233 gallons of water. AR(47) x CA(2000) x .6233 ≈ expected rainwater collection (58,591).
Once collected, how will I store my rainwater?
There are a variety of tanks available, ranging from the simple rain water barrel (holding anywhere from 50-100 gallons), to large underground cisterns. Depending on your individual needs, you can store as much water as you want above, or under ground.
How much rainwater do I need to collect?
It is generally recommended that you store two to three months water use. This generally provides an adequate cushion for dry periods or droughts.
How much can I expect to spend on my rainwater system?
Rainwater collection systems vary in price. Due to the great variance in our client’s needs, and in the systems available, we recommend an initial consultation to give us a chance to evaluate what will work best for you. Some elements of consideration are the scale and feasibility of the project, water usage, personal aesthetic preferences, and the water collection system of choice.
How much can I expect to save with my rainwater system?
In North Carolina the average price of water is around .0046 cents (about half of a penny) per gallon. 50-80% percent of most home or business water usage can be supplemented by harvested rain water. Depending on your situation and system of choice, your long term savings could be moderate to substantial. If your bill is usually $50 a month, you could save anywhere from $25-40 a month, $300-480 a year with the appropriate rain water harvesting system.
What is the difference between harvesting rainwater, grey-water, and potable water?
Rainwater is water than has been processed naturally, but is not safe for consumption without the use of filters. Rainwater may contain pathogens which can be easily treated with a UV filter.
Grey-water is water that has already been used for washing dishes, laundry, or bathing and must be treated in many states before use for irrigation. Grey-water contains residual chemicals, cleaning agents, and pathogens that require intensive treatment for domestic recycling.
Potable water is water that has either been filtered at home, by your city, or by large manufacturer of bottled water. A fair amount of energy goes into this process, whether it is human labor, electrical power, or both.
How exactly does a rainwater system help the environment?
The environmental benefits of rain water conservation range from simply saving the time, effort, and money involved in supplying a house or business with processed water, to the less obvious concerns of water being diverted away from its natural course by roads, parking lots, homes and businesses.
Most people do not often think of what it takes to get water into their home because as of now, it’s relatively inexpensive. However, the chain of events required is actually quite substantial when you consider that the effort goes toward nothing more fruitful than flushing drinkable water down the toilet 50-80% of the time. Utilizing rain water to flush toilets and irrigate landscapes (among its other many uses) makes the effort of processing water more practical, efficient, and most importantly, less wasteful. Think of how many fewer processing plants, pipes, and pumps would be required if the only water processed was the water people drank.
The issue of rain water diversion has become more prominent in our future. As our cities, businesses and neighborhoods expand, so does our concrete footprint. The larger our footprint becomes, the more rainwater we divert away from the soils and reservoirs underneath. Many of the rain water harvesting systems available have been designed with this issue in mind. Most in ground rain water tanks have overflow valve's which reroute the water to its natural path after your tank has filled. This rerouting also alleviates the load on storm run off systems, and can reduce localized flooding.
How is the collected rainwater filtered, and how much trouble is it to do so?
Your collected rainwater can be filtered in several different ways depending on your individual needs. The basic rain water barrel collects water straight from your gutter downspout where the water passes through a mesh filter to avoid the collection of debris and bugs. This water is safe to use for irrigation purposes.
Large above and underground tanks can be equipped with other filters, including a point of use UV filter that sterilizes your harvested rainwater right before use.
