For thousands of years, collecting rainwater for daily use was a common practice; but over the last century, wells and municipal water supplies have taken over as primary water sources.
Today, the diminishing supply of fresh water in wells and aquifers as well as concerns of quality and population growth have lead to a resurgence of rainwater catchment, according to the American Rainwater Catchment Systems Association (ARCSA).
We recently caught up with Heather Kinkade, executive director for ARCSA and champion for rainwater harvesting, to learn more about the organization, how rainwater harvesting works and the benefits to homeowners. Here’s what she had to say:
Tell us about the American Rainwater Catchment Systems Association. Who are you and what do you do?
In 1994, Dr. Hari J. Krishna of Austin, Texas founded the 501(c)(3) nonprofit American Rainwater Catchment Systems Association (ARCSA) to bring renewed attention to the ancient practice of rainwater harvesting.
ARCSA was created to promote sustainable rainwater harvesting practices throughout the United States and the world. Our mission is to promote sustainable rainwater harvesting practices to help solve potable, non-potable, stormwater and energy challenges throughout the world.
Top promotional efforts include: creating a favorable regulatory atmosphere; creating a resource pool; and educating professionals and the general public regarding safe rainwater design, installation, and maintenance practices.
Being a worldwide organization, ARCSA funds a virtual hub at www.arcsa.org. This cyber home offers the public a vast array of information and resources including a project gallery, workshop calendar, course agendas, professional location directory and more.
ARCSA is a membership-based organization whose benefits include access to leading news about the technology and advancements in rainwater catchment. The site establishes a forum for members to share and gain knowledge about the growing industry. Members include professionals working in city, state and federal government; academics; manufacturers and suppliers of rainwater harvesting equipment; consultants; backyard amateurs; and other interested individuals.
Why are you so passionate about rainwater harvesting? What are the benefits?
I personally am passionate about rainwater harvesting because it is a practice that keeps rain where it falls and, if collected and treated correctly, can allow a source of higher quality water than what is provided by municipalities. It is a decentralized water source that can be maintained by an individual. I have written two books on the subject, one of which is now published in Chinese. Forgotten Rain was my first book, and the second was Design for Water.
Rainwater can be used for any water need that municipal water is used for, and it does not need to be treated for most non-potable uses. Rainwater is also a soft water, so it has an added benefit of not requiring as much soap for cleaning needs. Collecting and reusing rainwater can allow a landowner to reduce storm water retention needs in most areas.
Can you tell us about one of the most exciting or innovative residential rainwater harvesting systems you’ve come across?
There are too many these days.
We have numerous examples on our website in the project gallery or the 2014 conference virtual tour. There are potable and non-potable projects that range in size from single family to large commercial. There are even rainwater systems for wildlife catchment for all sizes of animals – from hummingbirds and tortoises to bats and large game animals. We are even seeing swimming pools being turned into cisterns for rainwater catchment needs.
What can harvested rainwater be used for? Is there anything it shouldn’t be used for?
Rain can be used for any water need, and its purification level needs to meet its ultimate intended use requirements. Therefore, if it is to be used to wash typical vehicles, no treatment may be needed; but if it is needed to wash fighter planes, it might need to be treated to ultrapure water levels.
What are some basic ways homeowners can start harvesting rainwater?
Rainwater can be used in both active and passive ways. A gravity system is probably the simplest. A homeowner can catch and reuse the rainwater for passive landscape irrigation at a later date when the soils are dry. Rain barrels are what some people start with, but they soon see how easy and how much they can capture and often end up moving up to a larger tank.
What are some examples of more advanced harvesting systems?
All systems include the same components; it is just the size of storage, level of pumping, and purification needs that may vary. Again, there are lots of systems on the website under project profiles and the 2014 conference virtual tours.
What are some best practices for making sure a harvesting system is clean and safe?
As the emphasis on rainwater harvesting continues to grow, it is important to understand that a healthy rainwater harvesting system requiring minimal maintenance is essential as our industry continues to make positive strides and the rainwater-harvesting phenomenon moves from simple rain barrels to commercial applications.
Storm water laws require most new commercial construction to detain their storm water on the property and release it over time. This has created an opportunity for properly-designed rainwater harvesting systems to become more prevalent and be used to supply water for non-potable uses.
No matter how big or small the system, using four simple design steps will ensure the system is healthy and requires little maintenance. First and most importantly, the rainwater from the roof must be filtered to some level to remove debris that collects on the roof from the water before it goes to the tank. The quality of filter used will determine the amount of maintenance the pre-filter will need to successfully accomplish this first step. It is recommend that the pre-filter be self-cleaning, which requires minimal maintenance and provides highly oxygenated water. The correct pre-filter eliminates the need to ever clean the storage tank.
The second step in this simple process is to reduce any turbulence and introduce the oxygenated water into the tank. Every rainwater storage tank will grow a bio-film that serves as an internal ecosystem. Disturbing this bio-film by simply “dumping” the water into the tank will not allow for this ecosystem to flourish. Using the proper components will allow the water to gently enter the tank from the bottom and replenish the oxygen throughout the tank.
Step three to a healthy rainwater harvesting system is simply to extract the water from just below the surface of the water. Since we all know this, it makes sense to supply the water source with the highest quality water possible.
The final step to a healthy rainwater harvesting system is to allow the tank to overflow. This can be accomplished simply by allowing the water to exit the tank once it becomes full; however, using an overflow device that uses a skimming effect removes floating matter such as pollen from the tank more effectively. It is also recommended that some type of device is used to keep small animals from entering the tank through the tank overflow.
Providing high-quality water to the pump and any additional purification or filtration devices required for specific applications is essential for any rainwater harvesting system. Using this simple four-step process will ensure your rainwater harvesting system is of the highest quality and will require minimal maintenance regardless of the size of the system.
Are there any common laws or regulations homeowners should be aware of before creating a harvesting system?
Every state is different. ARCSA ASPE ANSI Standard 63 is one we have helped write; it can be purchased on our website bookstore.
What are some of the most common mistakes or oversights you see homeowners making when it comes to managing rainwater?
Maybe not designing large enough storage. Maybe collecting off a surface that is not appropriate for the end use; such as asphalt shingles that have a petroleum base, which can be picked up and carried in to the storage system, or collecting off new wood shakes that have been treated with an algaecide that kills the biofilm in the tank. Not using a pre-filtration can be a big mistake in some areas.
Where can homeowners learn more about rainwater harvesting?
At www.arcsa.org or by taking one of our rainwater catchment Accredited Professional Workshops.
For gutter protection that will make for easier rainwater harvesting, call Moonworks at 1-800-975-6666.