Rainwater Harvesting: Utilizing Nature's Gift for Irrigation

Have you ever received a gift card and saved it for months until you really needed it? That, essentially, is how rainwater harvesting works in gardening.

When you collect and store the rain that falls on your property, you’re holding on to a precious resource from nature for later use in your garden.

The process can be as straightforward as directing the water from your house’s rain gutters into a rain barrel equipped with a spigot. When you need the water, you’ll simply attach a garden hose to the spigot (or release the water into a watering can) and apply the water to your garden soil.

Some people opt for more intricate systems like multiple rain barrels interconnected by pipes or automated systems with sensors and timers.

Whatever system you use, when you collect rainwater, you’re doing something that benefits you, your garden, and the environment.

The benefits start with savings

The most obvious benefit of harvesting rainwater is it can save you money. Every saved raindrop you use to irrigate your garden is water you don’t have to get from your municipal utility. Over time, that can lower your water bills, especially during prolonged dry periods.

Or, depending on how you get your water, you could see savings on your electricity bill. If you use an electric pump to access your well water, rainwater harvesting can reduce the amount of power you use and lower your electricity costs.

In some regions, you may be able to tap into government or utility company rebates, tax incentives, or grants for installing and using rainwater harvesting systems, saving you even more money.

Yes, you will spend money to set up your rainwater harvesting equipment, but basic harvesting systems—like rain barrels or homemade collection systems—are not expensive. 

Another plus: Once installed, most rainwater harvesting systems need minimal maintenance compared to traditional irrigation systems. If you regularly clean your gutters and rain barrel filters, your rainwater harvesting systems likely will provide a reliable and cost-effective water source for years.

A treat for your plants

When you harvest rainwater, you’re doing your plants a favor, too. 

First, you’re sparing them from the treatment chemicals (including fluoride and chlorine) and salts in municipal water. These substances tend to accumulate in garden soil, and they’re not particularly great for plant health.

While your rainwater is free from potentially harmful substances, it also contains things that are good for your plants. Water collected from your rooftop is exposed to whatever is on it like leaves, pine needles, bird droppings, and pollen. (That’s why it’s not a good idea to drink your harvested rainwater straight from the barrel.) Those organic materials provide nourishment for your plants.

Rainwater also contains nitrates, a form of nitrogen, which is one of the things your plants need to thrive. And while some forms of nitrogen are not easy for plants to absorb, nitrates are optimal for plant uptake.

Not only that, but rainwater tends to have a slightly acidic pH level, which can be beneficial for many types of plants, especially acid-loving varieties like azaleas, rhododendrons, and blueberries.

Environmentally friendly irrigation

Some people are drawn to rainwater harvesting because of its environmental benefits. Collecting rainwater reduces stormwater runoff on residential property, and that, in turn, helps prevent pesticides, sediment, metals, and fertilizers from contaminating surface water sources like lakes and creeks.

By capturing rainwater before it runs off paved surfaces and directing it into the soil, you can also prevent soil erosion, which degrades soil fertility and leads to sedimentation in water bodies. 

Harvesting also is an effective way to conserve drinking water. When you use rainwater to irrigate your garden plants, you reduce demand for treated municipal water, which is often sourced from finite freshwater reserves.

Rainwater harvesting: Getting started

If you’d like to try rainwater harvesting, we have a few tips to help you get started.

Start by identifying the best spot(s) on your property to collect rainwater. Ideally, you want areas where rainwater naturally accumulates: near downspouts, rooftops, or paved surfaces.

Once you've determined the best locations, select a collection system that suits your needs. 

One of the most popular options among gardeners is to place a rain barrel under a rain gutter’s drain spout (also known as a downspout or downpipe) to collect rainwater from the roof.

Your average rain barrel will hold 50 to 100 gallons, but other sizes are available. Most have a screen or filter to prevent debris and insects from entering and a spigot for easy access to the stored water.

If you get a rain barrel, you’ll need to make sure your home’s rain gutters and drain spouts are properly positioned to direct rainwater into your barrel. Doing that might require gutter accessories or extenders.

Once your system is in place, you can start collecting rainwater and using it to irrigate your garden plants as needed with a hose or watering can.

Don’t forget regular maintenance. In addition to cleaning your home’s rain gutters and the barrel’s filters, you’ll need to clean the barrels themselves to prevent the buildup of debris, algae, and bacteria that can contaminate your stored rainwater.

Aim to clean your barrel at least once per year, preferably before the start of the rainy season or whenever you notice visible debris accumulation. To clean your rain barrel, empty it completely and scrub the interior with a solution of mild soap and water. Rinse thoroughly with clean water.

Nature is going to gift us rainwater one way or the other. Why not save it and reap all the benefits it can provide?