A 55-gallon rain barrel sitting at the corner of your house can collect, on average, around 1,500 gallons of usable water across a typical year. That number depends heavily on your local rainfall and roof area, but in nearly every climate that gets meaningful rain, the math is favorable. The water is free, soft, and immediately usable for almost everything outdoor: garden beds, container plants, washing the car, refilling the dog’s bowl, even flushing the toilet during emergencies.
Installing one is a Saturday-morning project. The hardest part isn’t the work. It’s choosing well and avoiding the small mistakes that turn a rain barrel into a frustrating drip-trickle of mosquito breeding water instead of a useful piece of garden infrastructure. The EPA’s Soak Up the Rain guidance gives a good sense of the environmental case, but the household case is often just: less turning on the tap.
What rain barrels actually do
A rain barrel is a container that catches rainwater from a downspout. Most are 50 to 80 gallons. They have a screened inlet at the top to keep debris and mosquitoes out, an overflow outlet near the top to handle storms that exceed capacity, and a spigot at the bottom for connecting a hose or filling a watering can.
For every inch of rain falling on every 1,000 square feet of roof, you collect roughly 620 gallons. A typical American roof shed contributes 300 to 800 gallons per inch of rain, which means a single moderate storm can fill a 55-gallon barrel two or three times over. Multiple barrels chained together capture more.
Choosing the barrel
The market has expanded considerably in the last decade. The basic options:
| Type | Price | Best for | Notes |
|---|---|---|---|
| Plastic (HDPE) 55-gal | $60 to $120 | Most homes | Lightweight, UV-resistant, often dark color |
| Repurposed food barrel | $30 to $60 | DIY/budget | Verify previous contents were food-safe |
| Decorative urn-style | $120 to $300 | Visible front-yard use | Higher cost for aesthetics |
| Slimline wall barrel | $100 to $200 | Tight spaces | Less capacity per dollar |
| Cistern 200+ gal | $300 to $800 | Serious gardeners | More water, more siting required |
For a first barrel, a basic plastic 55-gallon model with a built-in spigot, screened inlet, and overflow port is the safe choice. Look for these features specifically. Some cheap barrels lack proper overflow protection, which leads to flooding around the foundation in heavy storms.
Where to put it
The barrel goes under a downspout. Which downspout matters more than people realize.
- Choose one that drains a useful area. A downspout from a small porch roof won’t collect much. Pick one off a larger section of the main roof.
- Position it near the garden it will water. Carrying watering cans across the yard is fine for small jobs. For larger ones, having the barrel near the beds it serves saves significant effort.
- Allow gravity to work. A barrel needs to be raised, usually on cinder blocks or a stand, so the spigot is high enough for a watering can to fit under and for a hose to gravity-feed downhill to garden beds.
- Avoid the side of the house with the most visible curb appeal. Rain barrels are functional, not always beautiful. The back or side of the house usually works best.
The installation itself
The basic process:
- Measure the downspout where you want the barrel. Mark the new height for the cut, typically just above the height of the barrel’s screened inlet.
- Build the platform. Stack cinder blocks two-high, perfectly level, in a 2×2-block pattern. Cap with a plywood scrap if needed. The platform should sit on compacted ground, not loose soil.
- Cut the downspout with a hacksaw at the marked height.
- Install a diverter or elbow at the cut. A diverter routes water to the barrel and bypasses to the original drain line when the barrel is full. A simple elbow just routes water into the barrel and uses the barrel’s own overflow port.
- Position the barrel on the platform, aligned under the new downspout outlet.
- Connect the overflow port to a hose or extension that directs overflow safely away from the foundation, at least 5 feet from the house, ideally toward a planted area.
- Test with a watering can poured into the downspout above the barrel.
Total time: 1 to 3 hours depending on whether you use a diverter (more complex but more polished result) or a simple cut-and-route approach.
The mistakes to avoid
- Not raising the barrel. A barrel sitting on the ground produces almost no pressure at the spigot. A two-block lift gives enough gravity for a useful flow.
- No overflow management. Storms will exceed barrel capacity. Without a planned overflow path, water pools around the foundation and causes problems.
- Open inlet. A rain barrel with no screen becomes a mosquito factory within a week in warm weather. The mesh inlet is non-negotiable.
- Using rain barrel water for edible crops without consideration. Roof contaminants like bird droppings and asphalt particles can wash into the barrel. Use rain water for ornamentals freely; for vegetables, water the soil rather than the edible leaves, especially in the weeks before harvest. The CDC’s guidance on rainwater collection covers this in more depth.
Twice-a-year barrel care
Rain barrels need almost no attention, but a few annual chores keep them working:
- Clean the inlet screen once or twice a year. Leaves and debris accumulate.
- Empty and rinse the barrel at the end of each season in regions with hard freezes. Frozen water can crack the plastic.
- Inspect the spigot for drips.
- Check the overflow direction after major storms to make sure water still routes away from the foundation.
Local rules
Most regions allow residential rain barrels without restriction. A handful of dry-climate states have specific rules. Colorado, for instance, limited rainwater collection until relatively recently. A quick check with your municipal water department answers the question in a thirty-second phone call: “Are there any restrictions on installing residential rain barrels?”
The slow pleasure of it
The first time you water a garden bed with a hose connected to a rain barrel, it feels different from city tap water: softer, almost gentle. The plants seem to notice. The water bill notices too, eventually. It’s not life-changing money. It’s just one of those small, satisfying systems that quietly does its job, year after year, for almost no ongoing cost.
If you’ve been thinking about a rain barrel for a few seasons and not gotten around to it, this is the post that says: it’s a single morning of work. The savings start with the next rain.
Frequently Asked Questions
Can I connect two or three rain barrels together to store more water?
Yes, and it is one of the most useful upgrades a first-time barrel owner can make. Barrels are linked at the overflow port using a short section of hose or rigid PVC, so when the first barrel fills the water flows into the next. All barrels should sit at the same height on a common platform so the water level equalizes. A three-barrel chain gives you roughly 165 gallons of storage from one downspout, and you can add more as needed. Just make sure the final barrel still has an overflow directed away from your foundation.
Will a rain barrel work with a soaker hose or drip irrigation?
It can, but with limitations. Gravity from a two-block platform only produces about 1 psi per 2.3 feet of height, which is far below the 10 to 30 psi most drip systems expect. A short soaker hose lying downhill from the barrel will weep water and works reasonably well for a nearby bed. Long runs, uphill routing, or standard drip emitters usually will not perform without a small booster pump. If you want a full drip zone fed from stored rain, a raised cistern or a low-pressure drip kit rated for gravity feed is a better match than a standard barrel.
How long can rainwater safely sit in the barrel before it goes bad?
For non-drinking uses like garden watering, rain water can sit in a properly sealed barrel for many months without meaningful problems. A closed, screened barrel keeps light out and mosquitoes out, which are the two things that create real trouble. If you notice a strong smell, slime on the walls, or discoloration, drain the barrel, scrub it with a mild bleach solution (about a teaspoon per gallon of water), rinse well, and refill. Most home owners never need to do this more than once a year at the start of the growing season.
Do rain barrels actually save money on the water bill?
Modestly, and mostly in dry climates or on properties with significant outdoor watering. A typical household with one 55-gallon barrel might displace 1,000 to 2,000 gallons of municipal water per year, worth roughly $5 to $20 at average US rates. The real value is usually softer water for acid-loving plants and continued outdoor watering during municipal restrictions, rather than the dollars themselves.
