8 Supplies for Setting Up a Rainwater Harvesting System
Harness a sustainable water source. Our guide covers the 8 key supplies, from gutters and filters to barrels, for an efficient rainwater harvesting system.
Watching the garden wilt during a mid-summer dry spell is a frustrating sight, made worse by the sound of the well pump kicking on yet again. A simple rainwater harvesting system turns your barn or house roof into a powerful tool for water security. With the right components, you can capture thousands of gallons of clean, naturally soft water to keep your plants thriving and reduce your reliance on municipal or well water.
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Why Harvest Rainwater on Your Hobby Farm?
Capturing rainwater is about more than just a free resource; it’s about water quality and resilience. Municipal water often contains chlorine and other chemicals that can be harsh on sensitive seedlings and soil microbiology. Well water can be hard, with high mineral content that builds up in the soil over time. Rainwater, by contrast, is naturally soft, slightly acidic, and free of these additives, making it the ideal choice for nurturing a healthy garden ecosystem.
On a practical level, a rainwater system provides a crucial buffer during dry periods or in areas with watering restrictions. A few 50-gallon barrels can easily sustain a kitchen garden, a small flock of chickens, or a collection of potted plants through a week without rain. For a hobby farmer, this means less stress on your well, a lower water bill, and the peace of mind that comes from having a backup supply. It’s a foundational step toward a more self-sufficient and sustainable operation.
Gutter Screen – Amerimax Lock-In Gutter Guard
Keep gutters flowing freely with Amerimax Lock-In Gutter Guards. The tight mesh prevents debris buildup, while durable, powder-coated steel ensures long-lasting protection and easy lock-in installation.
Your first line of defense in a rainwater system is keeping large debris out of the water. Leaves, twigs, and shingle grit will quickly clog your pipes and turn your rain barrel into a sludge-filled mess. A quality gutter screen prevents this from ever happening, ensuring the water entering your downspout is as clean as possible from the start.
The Amerimax Lock-In Gutter Guard is the right tool for this job. Made from powder-coated steel, it won’t warp in the sun like cheap plastic or vinyl guards, and its tight mesh blocks everything from maple seeds to pine needles. The "lock-in" design is key—it snaps securely onto the front lip of standard K-style gutters, preventing it from blowing off in a storm. Installation requires no special tools, just a pair of tin snips for cutting to length.
Before you buy, measure the width of your gutters; these are designed for standard 4, 5, or 6-inch K-style gutters. While they do an excellent job, you’ll still need to brush them off once or twice a year, especially after heavy leaf fall. This guard is for the farmer who wants a durable, set-it-and-forget-it solution, not someone who wants to be cleaning out their gutters every month.
Downspout Diverter – Oatey Mystic Collection System
A downspout diverter is the heart of your collection system, channeling water from the downspout into your barrel while allowing excess water to continue down and away from your foundation. A good diverter is efficient, easy to install, and automatically handles overflow. Without one, you’re stuck with a messy, inefficient setup that either overflows constantly or requires manual intervention.
The Oatey Mystic Collection System is a perfect fit for a hobby farm setup because it’s a complete, well-designed kit. It includes the diverter body, a high-flow hose, and the necessary seals. The internal design creates a channel that directs water to the barrel until it’s full; once the water level in the barrel reaches the diverter’s outlet, back-pressure automatically sends all subsequent rainwater back down the spout. This prevents dangerous overflows right next to your foundation.
This system is designed for standard 2×3-inch or 3×4-inch rectangular downspouts, so confirm your sizing before purchasing. Installation involves cutting a section out of your existing downspout, which can feel intimidating but is straightforward with a hacksaw and a measuring tape. The Oatey Mystic is ideal for anyone who wants a reliable, all-in-one solution without piecing together parts from the hardware store.
Rain Barrel – Good Ideas Impressions 50-Gallon Rain Saver
The rain barrel is where you store your captured water, so its design and material matter. You need something durable enough to withstand years of sun and weather, opaque to prevent algae growth, and designed for easy access. Avoid cheap, thin-walled plastic barrels that can crack or become brittle over time.
The Good Ideas Impressions 50-Gallon Rain Saver is an excellent starting point. Its rock-like texture and flat-back design allow it to sit snugly against a wall, looking more like a landscape feature than a piece of plumbing. More importantly, it’s made from thick, BPA-free polyethylene that blocks sunlight to prevent algae growth, a common problem in translucent barrels. The top features a recessed channel for self-draining and a removable, screened lid to keep out debris and mosquitoes.
A 50-gallon capacity is a manageable size for a small garden or for watering livestock, and multiple barrels can be linked together as your needs grow. It comes with a basic plastic spigot, which is functional but should be upgraded for longevity. This barrel is for the hobby farmer who values durability and aesthetics and wants a ready-to-go solution that will last for many seasons.
First Flush Diverter – Rain Harvesting Water Diverter
Collect rainwater easily with this versatile downspout diverter. It fits various downspout sizes, filters debris, and connects to standard hoses for efficient water distribution.
The first few minutes of any rainfall wash the accumulated dust, pollen, bird droppings, and shingle grit off your roof. A first flush diverter is a simple but critical device that captures and isolates this initial "dirty" water, preventing it from contaminating the rest of the water in your barrel. Skipping this step means you’re storing lower-quality water and will have to clean sediment out of your barrel far more often.
The Rain Harvesting Water Diverter is a simple, effective, and widely-used model. It’s an in-line chamber that installs on your downspout before the main diverter. As rain begins, the chamber fills with the initial dirty water; a floating ball then rises and seals the entrance, allowing the subsequent clean water to flow past and into your barrel. After the rain, a slow-drip release at the bottom of the chamber automatically empties it, resetting the system for the next storm.
This component adds a bit of complexity to your setup but pays for itself in water quality and reduced maintenance. You’ll need to calculate the right length for the diverter chamber based on your roof area—the general rule is to divert at least one gallon for every 100 square feet of roof. This is a non-negotiable component for anyone serious about using their rainwater for vegetable gardens or for animals.
Choosing the Right Location for Your System
Where you place your rain barrel is just as important as the components you choose. The ideal location balances four key factors: proximity to a downspout, a stable and level base, elevation for water pressure, and distance from your foundation. Most collection systems are designed to be fed directly from a downspout, so pick a corner of your house, barn, or shed that is convenient.
Your barrel must sit on a solid, level surface. A full 50-gallon barrel weighs over 400 pounds, so placing it on soft ground will cause it to tilt and potentially tip over. A base of compacted gravel, concrete pavers, or a dedicated rain barrel stand is essential. Elevating the barrel on cinder blocks or a sturdy stand is also crucial. This elevation creates head pressure, allowing water to flow more easily from the spigot and into a watering can or through a soaker hose.
Finally, always manage your overflow. Even with a diverter, you need a plan for where excess water will go. Ensure the main downspout and your barrel’s overflow hose direct water several feet away from your building’s foundation to prevent water damage, basement leaks, or soil erosion. A little planning here prevents major headaches later.
Tank Inlet Screen – Blue Mountain Co. 90mm Screen
Even with gutter guards, fine debris and, most importantly, mosquitoes can find their way into your rain barrel. A tank inlet screen is the final barrier, fitting securely over the barrel’s opening to keep the water clean and prevent it from becoming a breeding ground for pests. This is a small, inexpensive part that provides essential protection.
The Blue Mountain Co. 90mm Screen is a simple, robust solution. It’s a fine stainless steel mesh screen set in a durable PVC frame, designed to drop right into a standard 90mm (approximately 3.5-inch) opening. The stainless mesh is fine enough to block mosquitoes and leaf fragments but won’t impede water flow during a heavy downpour. Unlike flimsy fabric screens, it won’t tear or sag over time.
This screen is a perfect companion to barrels that have a simple, open inlet hole. If your barrel already has an integrated screen, check its quality—many are made of cheap plastic mesh that degrades in the sun. This drop-in screen is a worthy upgrade for ensuring your water stays clean and your yard stays mosquito-free. It’s for anyone who understands that a successful system is about managing the small details.
Barrel Spigot – American Valve M71HD Brass Spigot
Most rain barrels come with a cheap, plastic spigot that restricts flow, leaks, and breaks after a season or two of use. Replacing it is one of the easiest and most impactful upgrades you can make. A high-quality spigot allows you to fill a watering can quickly and will last as long as the barrel itself.
The American Valve M71HD Brass Spigot is the perfect replacement. It’s a quarter-turn ball valve, which means it opens and closes quickly with a simple flick of the handle. Made from heavy-duty brass, it won’t rust or become brittle from UV exposure. The full-port design offers a much higher flow rate than the standard plastic spigots, cutting down the time it takes to drain water.
Installation is simple: just unscrew the old spigot and screw this one in, using plumber’s tape on the threads to ensure a watertight seal. It has a standard 3/4-inch thread that fits most rain barrels and garden hoses. This is not an optional upgrade; it’s a fundamental improvement for anyone who plans to use their rain barrel regularly and wants a frustration-free experience.
Overflow Hose Kit – EarthMinded Rain Barrel Overflow Kit
Prevent rain barrel overflow and protect your home with this easy-to-install kit. The flexible, 5-foot hose directs excess water where you need it to go.
Every rain barrel needs an overflow port. When the barrel is full, this port safely directs excess water away from the barrel and, more importantly, away from your foundation. A proper overflow system is a non-negotiable safety feature that prevents soil erosion and potential water damage to your home or outbuildings.
The EarthMinded Rain Barrel Overflow Kit provides all the necessary components in one package. The kit includes a high-quality hose, seals, and a hose clamp, taking the guesswork out of finding compatible parts. The included drill bit and instructions make it easy to add an overflow port to any plastic barrel that doesn’t already have one. This allows you to position the overflow to direct water exactly where you want it—to another barrel, a nearby garden bed, or a drainage area.
This kit is particularly useful for linking multiple barrels together in series. By connecting the overflow of the first barrel to the inlet of a second, you can easily expand your storage capacity. This is a must-have for anyone building a DIY system or for those whose pre-made barrel has an inadequate or poorly placed overflow. It’s a small investment that protects your much larger investment: your home’s foundation.
Soaker Hose – Gilmour Flat Weeper Soaker Hose
The water from a rain barrel is delivered at very low pressure—it’s gravity-fed, not pumped. This means it won’t work with standard sprinklers or many spray nozzles. The best way to use this water efficiently is with a soaker hose, which weeps water slowly and directly into the soil at the base of your plants.
The Gilmour Flat Weeper Soaker Hose is an excellent choice for gravity-fed systems. Unlike round soaker hoses that require higher pressure to work evenly, this flat-style hose is designed to weep water consistently even at low pressure. It’s made from a tough, vinyl fabric that resists clogging and UV degradation. The flat design also makes it easy to snake through garden rows and store neatly when not in use.
For best results, your rain barrel should be elevated at least one to two feet above the garden bed to provide enough head pressure. This hose is perfect for watering raised beds, vegetable rows, and foundation plantings without wasting a drop to evaporation. It’s the right tool for anyone who wants to put their harvested rainwater to work in the most efficient and effective way possible.
Essential Maintenance for Clean Rainwater
A rainwater harvesting system is wonderfully low-maintenance, but it isn’t no-maintenance. A few simple, seasonal tasks will keep your system running efficiently and ensure your water quality remains high for years to come. Neglecting these steps can lead to clogs, contamination, and a shortened lifespan for your components.
In the spring, give the entire system a thorough cleaning. Scrub the inside of the barrel with a brush and a mild vinegar solution to remove any sediment or biofilm that formed over the winter. Re-install your diverter and ensure all screens—on the gutters, barrel inlet, and first flush diverter—are clean and free of debris. This is your chance to check all connections for leaks before the heavy spring rains begin.
Throughout the growing season, periodically check your gutter screens and clear away any accumulated leaves or twigs. After a long dry spell, it’s also wise to check and clean the first flush diverter. In the fall, prepare for winter by draining the barrel completely, disconnecting the diverter, and leaving the spigot open. This prevents water from freezing and cracking the barrel or its fittings, ensuring your system is ready to go again next spring.
Putting Your Rainwater System to Good Use
With your system set up and collecting water, the final step is to use it effectively. The primary use on a hobby farm is irrigation, where rainwater’s softness and purity offer significant benefits over treated or hard water. Use a watering can for targeted watering of containers, new transplants, and sensitive seedlings that can be damaged by the high pressure of a regular hose.
For larger areas like vegetable beds or berry patches, the soaker hose is your best tool. Lay it out at the beginning of the season and let it do the work, delivering water directly to the root zone. This method minimizes evaporation and fungal diseases that can be caused by overhead watering. Remember that a 50-gallon barrel will empty surprisingly quickly, so prioritize your most valuable or water-needy plants first.
Beyond the garden, harvested rainwater is perfect for mixing fertilizers, washing tools, or topping off water for chickens and other livestock (provided your roof is free of contaminants like lead paint or heavy moss treatments). By matching the use to the quality of the water, you maximize the value of every gallon you collect. It’s a simple, powerful way to close a loop on your farm and make the most of a precious resource.
Setting up a rainwater harvesting system is a weekend project that pays dividends for years. It’s a practical investment in your garden’s health and your farm’s resilience. By choosing durable, well-designed components, you build a reliable system that works with nature to support your efforts.
