Why, How, and What is Rainwater Harvesting?

In this economy, we’re saving where we can. In this Redfin article, we’re covering everything you need to know about harvesting rainwater at your home. Whether you’ve always wanted a barrel system for your house in New Milford, CT, already have a catchment system at your rental home in Tucson, Arizona, or are interested in saving some money, keep reading for answers to why, how, and what is rainwater harvesting.

photo courtesy of Pioneer Water Tanks America

Table of Contents

• What is rainwater harvesting?
• Why should you survey?
• How: harvesting rainwater ideas
• Should I start harvesting rainwater?
• FAQs

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What is rainwater harvesting?

Rainwater harvesting, or RWH for short, is the practice of collecting and storing rainwater for later use rather than just letting it run off. This “sustainable and simple yet powerful practice not only conserves water and reduces one’s footprint, but also helps protect nature and secure the future,” says Chandrima Debi.

Pros of rainwater harvesting

• Reduces your water bill“By collecting and storing rainwater from rooftops, households can save money and lower their utility bills by using the water for irrigation, flushing toilets, washing vehicles, and more,” says Brandi Whitaker, account and business development manager of Pioneer Water Tanks America.
• Minimizes the strain on municipal systems
  By decreasing the demand for treated water and lessening the load on drainage infrastructure, “collecting rain at home is a simple and eco-smart way that reduces strain on municipal systems,” says Homesteadin’ Hawai’i.
• Supplies you with a backup water source
  “This practical and eco-friendly solution for residential homes provides a reliable backup water source during droughts, water restrictions, or other emergencies,” says Brandi.
• Nourishes your garden
  Harvesting rainwater can be extremely beneficial for a home garden since “rainwater is naturally soft, free of chlorine, and ideal for plants,” says Matt Lebon, owner and founder of The Foodscaper.
• Prevents erosion and runoff pollution
  By capturing rainwater where it falls, rainwater harvesting reduces the volume and speed h the water flows, thus helping to prevent erosion and runoff pollution.

Cons of rainwater harvesting

• Initial cost
  While harvesting rainwater can save you money in the long run, the initial setup cost can be relatively expensive. When installing it’s especially important to not cut corners as improper systems can cause damage like hazardous water.
• Storage limitations
  Some smaller homes and properties may not have the space required to have a proper storage system
• Water quality concerns
  If not set up correctly, collected water can become contaminated by outside pollutants like animal droppings, dust, attract algae, or become a breeding ground for mosquitoes. It’s especially important to ensure the system is properly sealed, filtered, cleaned, and maintained to ensure the water is safe for use.

Why should you survey?

“Before implementing any water-harvesting techniques, understanding your land is crucial,” advises Santa Cruz Permaculture. As every plot of land varies, “effective rainwater harvesting is more than just placing a barrel under a downspout — it’s a system rooted in strategy, not sentiment,” reminds Diego Torrelio, founder and CEO of Circlefoot. 

For example, in the Bay Area, “where rainfall is sporadic and storage is limited, the real ROI begins by restoring the soil since it acts as your first reservoir,” says Diego. In this climate, he recommends first “focusing on healthy soil, followed by integrated plant systems and then subsurface or above-ground cisterns sized to your actual hydro capacity and landscape demand if needed.”

Since what’s needed differs, it’s important to first “assess your site’s topography and water flow patterns to inform effective design,” reminds Santa Cruz Permaculture.

How: harvesting rainwater ideas

Now that you’ve surveyed your land, it’s time to decide on which rainwater harvesting system is right for you, your home, and your land. While it can be complex understanding the various systems, it can be helpful to break it into four main parts: catchment, conveyance (transportation), storage, and distribution.

Rain barrels

One of the most popular, simple, and cost-effective catchment and storage options is the rain barrel. Typically, these are placed at the bottom of downspouts to catch runoff during rainfall. Since the rainwater is also stored inside the barrel, most also have a spigot at the bottom for easy access along with a mesh screen to filter out debris.

Cistern tank

For a more advanced collection system, consider an above- or underground cistern tank. Like a rain barrel, a cistern tank also collects and stores rainwater, but these can hold hundreds or even thousands of gallons. This system allows you to “capture roof runoff to use for watering plants, washing outdoor surfaces, or even flushing toilets (with proper filtration) and can thus reduce demand on the local water supply, cut your water bill, and help manage stormwater runoff that can otherwise lead to pollution like microplastics in local waterways,” adds Kara Young, marketing director of Rainplan. 

photo courtesy of Pioneer Water Tanks America

Downspout extender

A downspout extender focuses on the catchment and transportation of rainwater. This device is attached to the bottom of a roof downspout to help direct the rainwater into a collection container, like a rain barrel. “Adding an extender to your downspout is a low-cost and eco-friendly way to harvest and redirect water to your plants [or storage container for other uses] instead of the storm drain,” adds Mackenzie Sanders, development manager of The Park People.

Brush dams and gabions

For stabilizing eroded gullies and seasonal drainages, Santa Cruz Permaculture recommends using brush check dams and gabions. These structures help “aid in landscape restoration by slowing water flow and promoting sediment deposition.” 

A dam helps to store the rainwater by creating a reservoir, whereas gabions control the water speed and spread. Together, they both help to retain moisture in the landscape as well as improve long-term water availability, which is especially effective for harvesting and managing rainwater in larger and more erosive-prone landscapes.

Berms and swales

If your house is built on a slope, consider “berms and swales, a simple water harvesting technique that involves shaping the earth to slow and infiltrate the flow of rainwater on a slope,” describes Santa Cruz Permaculture. This method is extremely cost-efficient as it only requires a shovel, sloped terrain, and some manual labor. This strategy is “designed to intercept rainwater running down the slope and infiltrate this water in a localized area, providing significant benefits to the landscape and your local watershed like enchanting soil moisture and reducing erosion,” adds Santa Cruz Permaculture.

photo courtesy of Santa Cruz Permaculture

Greywater raingardens

“Harvesting rainwater and greywater reuse offers a smart, sustainable way to conserve water with raingardens and greywater irrigation systems helping homeowners reuse water efficiently for landscape irrigation, drought resilience support, and healthy landscape building,” says Avery Ellis of United Ecology and Colorado Greywater.

Raingardens are shallow depressions that help catch rainwater runoff, slow water flow, and soak it into the ground. This natural and attractive rainwater design is filled with plants – hence a garden – and improves soil infiltration, filters pollutants, and supports biodiversity. 

Custom rain catchment systems

Since the best rainwater harvesting system for your home depends on your climate and landscape, consider seeking help from locals.

A simple search will help you find a local company specializing in local rainwater harvesting system design and installation. For instance, if you live in Oregon or another place with an increased water scarcity, Peter Thomas of Oregon Rain Harvesting, recommends “a rain catchment system made to provide water security and take pressure off already stretched water resources.” 

Similarly, you can consider working with a local company that keeps your region and personal needs in mind. For example, if you live in Texas, where drought and well reliability are growing concerns, companies like Holden Rainwater help to “design and install systems that provide clean, dependable water for drinking, bathing, cooking, and more – especially in areas where every drop counts.” Choosing something more tailored to your home, area, and can also help increase the benefits of your system.

photo courtesy of The Foodscraper

Should I start harvesting rainwater?

Now that you know the answer to “What is rainwater harvesting?”, the next question is, should you start the process at home? We unfortunately can’t answer this question for you, but we recommend first analyzing your home, region, personal needs, budget, and local laws. However, not only is being environmentally friendly and sustainable a great trend, but rainwater, as a resource is often overlooked, yet critical for survival,” reminds JB Rainwater Harvesting. 

So, “Whether you’re collecting for irrigation or planning a whole-house potable system, harvesting rainwater can truly transform your roof into a resource,” says Erin Moeller, vice president of Harvest Rain. 

Installing a rainwater system “can make a tangible difference for our planet by promoting ecological balance, economic stability, and climate resilience, and since every individual has a role to play — by adopting rainwater harvesting, we can collectively contribute to a sustainable future and ensure water security for generations to come,” adds JB Rainwater Harvesting. 

After all, “a well-designed rainwater system doesn’t just reduce your water bill, it builds long-term property resilience and helps reduce impact on local water sources,” reminds Erin.

FAQs

Is harvesting rainwater illegal?
There are currently no federal laws prohibiting rainwater harvesting, but restrictions and permits vary by state.
Before you start harvesting, we urge you to look into the local guidelines. Marianna Sachse, founder and CEO of Jackalo, recommends that you “contact your local government to see what sorts of incentive programs they offer.” For example, her city “offset the cost of rain barrel installation as part of their river smart program.”

Is a rainwater harvesting system expensive?
This depends on the system you choose, but rainwater harvesting systems typically “offer a practical, affordable, and flexible solution that works in both urban and rural settings,” says Moshe Belilty of Hilico. Especially since these systems can help lower your utility bills, installing a rainwater harvesting system can act as an investment and save you money over time.

Is harvesting rainwater similar to solar panels?
Both harvesting rainwater systems and solar panels are home additions that can help you “generate your own clean energy, reduce your bills, and minimize your environmental impact,” says Ivan Lu of Ivan the Solar Guy. “Pairing solar and rainwater harvesting can be a smart move for any homeowner looking to live more sustainably and save money in the long run,” adds Ivan.