As weather patterns become increasingly erratic, drought, water stress, and high utility bills can make gardening and watering your plants a real challenge. To make your garden more water-wise and resilient, capturing and using rainwater for plant irrigation may be worth the investment.

In this guide, you’ll learn how to create a simple and inexpensive system for harvesting rainwater, discover ways to upgrade existing rainwater collection systems, and find out how to maintain a functioning rain barrel for many years to come.

Is Harvesting Rainwater Legal?

There’s a common misconception that harvesting rainwater is illegal. However, in many areas, collecting rainwater is not just legal but encouraged.

In the past, rainwater collection was prohibited in some states, but today, harvesting rainwater is legal in most locations, and many local governments actually offer rebates and other incentives to encourage homeowners to harvest their own rainwater for climate resilience, water savings, and more.1 However, it’s always wise to educate yourself about local rules and regulations.

Benefits of Harvesting Rainwater

If you’re new to collecting rainwater for garden irrigation, you may wonder why it’s worth the trouble when you can get water straight from the tap. But harvesting and using rainwater in your garden has several advantages that you may not expect :

• It saves money. Rainwater harvesting systems can be created from inexpensive or upcycled materials that don’t cost much at the outset. Once installed, these systems can potentially capture thousands of gallons of rainwater for free and drastically reduce utility bills.

• It’s easy. Rainwater collection systems can be complicated, but they don’t need to be. In fact, a basic rainwater harvesting system can be as simple as placing a bucket below your downspout.

• It’s eco-friendly. Capturing rainwater reduces water waste, but that’s not all. It can also reduce runoff and help to counteract erosion.

• It’s good for plants. Tap water often contains chlorine, salts, and other additives that aren’t great for plants and can build up in the soil. However, rainwater is free of these contaminants and is particularly good for plants with sensitive root systems or salt sensitivity.

• It makes gardens more resilient. Collecting rainwater gives you more control over your water supply and can serve as a safeguard for your garden. Even if towns place water restrictions on tap water or your well runs dry, you can still water your plants with your rain barrel.

Steps to Harvest and Use Rainwater

Most rain barrels collect water directly from the roofs of houses, and most rooflines work well with rainwater collection systems. You can either purchase a premade rain barrel online or from a specialty garden center, or opt for a simple, DIY rain barrel to cut costs by following the steps below.

1. Calculate How Much Water You Can Harvest
Before installing a rain barrel system, it is helpful to calculate how much rain you can reasonably expect to collect. To do this, multiply the square footage of your roof by the average annual rainfall in your area in inches and multiply this number by 0.623. This will give you the approximate number of gallons of rain you should be able to collect per year.
Example : 1,000 square foot roof x 1-inch average rainfall per year for your region x 0.623 = 623 gallons of rain collected annually.

2. Choose the Right Collection Vessel
Many vessels can be used to collect rainwater, but 55-gallon plastic drums or 275-gallon IBC totes are popular picks. These vessels are available new or used, but it’s important to ensure they’re made of food-grade materials and that recycled ones haven’t been used for materials that aren’t safe for gardens where edibles are grown. IBC totes are particularly handy for rainwater collection as they come with pre-installed spigots, but you can add a spigot to plastic barrels, too.

3. Install the Barrel
Store-bought rain barrels may come with hoses for installation, but DIY rain barrels are even easier to install. Just cut an opening in the top of your rain collection vessel if needed, and locate the vessel below the drip line of your roof or beneath a downspout so that rain is channeled directly inside. If the ground is uneven, take the time to level it with a shovel or gravel before moving your barrel into position.

4. Add Safety Measures
Rain barrels should have a tightly fitted lid to keep animals out. If your rain collection vessel has any openings at the top or sides, cover the openings with fine mesh so that mosquitoes and other creatures won’t find their way inside.

5. Raise It Up
You can install rain collection systems directly on the ground, but water pressure will be higher if you raise them up. Laying one or two sturdy layers of cinderblocks beneath your rain collection system increasess water pressure dramatically and helps hoses work better.

6. Consider Upgrades
If you’re new to collecting rainwater, it’s a good idea to start small and scale upwards as needed. You can always add more barrels for rain collection or increase the size of the vessel you’re using later on. Adding a spigot or pump system to your barrel can make watering even easier, but it’s not required.

7. Water Your Plants
When it comes time to water your garden, collect water from your rain barrel by removing the lid or by opening up the spigot if your barrel has one. Then, simply fill a bucket or watering can. You can also install a garden hose directly to a rain barrel spigot as long as the connections fit.

Maintaining a Rainwater Harvesting System

Rain barrel systems don’t require much upkeep and they can pay for themselves over time. But if you want to keep your rain harvesting system in tiptop shape, here are a few maintenance tips to remember.

• Keep gutters clean. To maximize rainwater collection and avoid clogs, make sure to clean your gutters regularly or install gutter guards.

• Clean barrels. If algae grows in your rain barrel, it won’t cause damage, and the water will still be safe to use in your garden. That said, it’s still a good idea to drain and scrub rain barrels regularly to keep them clean and reduce the risk of clogs.

• Inspect for leaks. Check rain barrels, and spigots in particular, every so often to ensure they’re working properly and don’t have any leaks.

• Check screens and lids. For safety, keep rain barrels covered with sturdy lids and ensure screening is hole-free so that mosquitoes won’t lay eggs in your collected water.

• Winterize systems before cold weather. At the end of the season, rain barrels should be drained and moved indoors or turned upside-down to keep water from collecting inside and causing damage. If your rain barrel has a spigot, leave it open for the winter.

How to Harvest Rainwater at Home to Lower Your Water Bills by Lauren Landers | Better Homes & Gardens