Benefits of Rainwater Harvesting

07/19/2016 16:27

Rainwater harvesting - also known as rainwater catchment, rainwater capture, or rainwater collection - is the simple act of collecting the rainwater that runs off the hardscapes on your site (or house) for beneficial use. Passive rainwater harvesting methods include infiltration basins and bio-swales, that slow or stop the flow of runoff across your site. This allows storm water to infiltrate into the ground, hydrating soils and recharging groundwater. Active rainwater harvesting refers to catching and storing water in rain barrels, rank tanks, or cisterns for later use. If used in the garden, stored rainwater will also hydrate soils and recharge groundwater. With active rainwater harvesting, you control when and how the water is used.

Rainwater Harvesting is an obvious necessity for off-grid living, but why collect rainwater if I already have water available from the city or a well?

Rainwater harvesting is rising in popularity with renewed concerns about water supply, resource consumption, global climate change, and emergency preparedness. Many think of it as a new technology whose time has come, but at BlueBarrel we like to remind folks that rainwater harvesting is an ancient technology whose time has returned. Truth is, people have been collecting rainwater since the beginning of time as part of living in harmony with the land.

Why Should You Consider Harvesting Rainwater?

Protect the Environment

The environmental benefits to collecting rainwater onsite are many! When you install a rainwater catchment system you are aligning with Mother Earth in a variety of ways:

  • Reducing your draw on stressed systems: Aging water infrastructure is expensive to update, and groundwater and reservoirs are often overdrawn. When you supply a portion of your own water from the rain that falls on your roof, you reduce your draw on these stressed systems.
  • Restoring the hydrologic cycle: In a natural landscape, approximately 50% of storm water infiltrates into the ground, recharging groundwater. About 40% evaporates, and only 10% runs off. In developed landscapes by contrast (e.g. our neighborhoods!), only 15% infiltrates and a whopping 55% runs off! When you collect rainwater for use in your garden, you fix the broken hydrologic cycle by restoring the infiltration link.
  • Managing storm water to protect your local watershed: When rainwater infiltrates onsite, it is prevented from entering storm drains and surface waters as polluted runoff. Left unmitigated, rainwater sheets off hardscapes collecting contaminants along the way. If everybody captures a little, we can take the peak off storm loads and the associated erosion and pollution. The result is healthier waterways.
  • Reducing your carbon footprint: There is a strong nexus between energy and water in our modern world. In the state of California, for example, 20% of per-capita energy use is dedicated to treating, heating, and transporting water! By reducing your reliance on pumped and treated water sources, you are contributing to a collective savings in energy.

Nourish Your Plants

Rainwater is high-quality water that is especially great for plants. Why? Four primary reasons:

  1. 100% soft water source: Rainwater is free of the salts, minerals, pharmaceuticals, and heavy metals that leach into groundwater and surface waters. Of course it is also free of the treatment chemicals found in municipal water. Rain is a 100% soft water source!
  2. Contains organic matter: If caught from a rooftop and stored in barrels, rainwater will accumulate a small amount of organic matter which can be very beneficial to your garden. It's like a light application of fertilizer every time you water.
  3. Perfect pH balance: Rainwater tends to be slightly acidic. Most organically grown plants prefer a soil pH of 5.5 – 6.5, which is on the acidic side of the neutral pH 7. It's no coincidence that rain has the perfect pH – it's nature's design! Rainwater can help you maintain the perfect soil pH balance.
  4. Natural nitrate delivery: Rainwater contains nitrates – the most bio-available form of nitrogen. This is one of the three macro-nutrients that plants rely on. Again, no coincidence – nature intended it this way.

Be Prepared for Emergencies


There is tremendous peace of mind in knowing that you have many gallons of water stored and accessible on your site in the case of an emergency. While collected rainwater is not potable without treatment, in an emergency it can be disinfected with a variety of home-scale techniques for a reliable emergency water supply. In today's world, emergency preparedness is key.

Save Money

The cost of water is rising in most regions and this trend is expected to continue with no end in sight. When you meet some of your water needs with rain, whether you're on a municipal water meter or a private well, you will see ongoing cost savings. Metered sites will see a drop in metered consumption, and those using wells will save in energy costs due to reduced pumping. And speaking of costs savings, many cities and water districts sweeten the pot by offering rebates and incentives for rainwater harvesting. Click to learn about rebate options in your area!

Increase Awareness and Well-Being

Home-scale measures such as collecting rainwater for irrigation help us become more aware of our resource use. You will find yourself tuning into nature's flows as you observe the rate at which your rainwater system fills and empties, and the health of your garden throughout the seasons. You may connect with friends and neighbors to share inspiration about what you are doing to be more sustainable in your home, and adding to the collective resilience of your community. There is a sense of well-being and invigoration that comes with understanding and living in proportion to the earth's resources, and in turn, enjoying the garden's bounty!

Ready to Get Started Harvesting Your Own Rainwater?

Visit BlueBarrel Rainwater Catchment Systems for your DIY rain barrel kit!


Jesse Savou is the founder of BlueBarrel Rainwater Catchment Systems.


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