Rain barrels collect and store rainwater runoff from a roof, promoting water conservation and reducing stormwater runoff. This captured water is beneficial for landscape irrigation, as it is naturally free of the chlorine and salts often found in municipal supplies. While many systems rely on traditional gutters and downspouts, it is possible to set up an effective rainwater harvesting system without them. These methods focus on the natural flow paths of roof runoff to successfully collect and store water.
Preparing the Barrel and Foundation
The first step for any rain barrel setup is modifying the container to ensure functionality and safety. You must install a spigot or outlet near the bottom of the barrel, which allows gravity to provide pressure for easily dispensing the collected water into a watering can or hose. A sealed connection, often achieved with Teflon tape and waterproof sealant, prevents leaks at this low-point access.
An overflow mechanism is necessary to manage heavy rainfall once the barrel is full. This is achieved by installing a hose or valve near the top of the container. The overflow pipe should be directed at least six feet away from the home’s foundation to prevent water accumulation and potential damage to the structure.
A fine mesh screen must be placed over the main inlet hole to prevent contamination and insect breeding. This screen filters out debris like leaves and twigs, and blocks mosquitoes from accessing the water and laying eggs. The barrel must also be elevated using a stable platform, such as stacked cinder blocks, concrete pavers, or a wooden stand. This elevation utilizes gravity, creating sufficient water pressure for the spigot to function.
Direct Collection from Roof Eaves
The most straightforward method for gutter-less collection is positioning the barrel directly beneath the roof’s drip line. You should observe the roof during a rain event to identify the eaves where water naturally cascades most heavily, often in a concentrated stream at a roof valley or corner. The barrel’s screened inlet must be aligned precisely under this point of maximum runoff.
To maximize capture, the barrel’s inlet should be as wide as possible or utilize a large, rigid funnel to direct the falling water. Since the water is falling directly from the roof edge, it is susceptible to scattering and splashback upon impact. Placing a layer of coarse gravel or a few flat splash blocks around the barrel’s base helps to mitigate soil erosion caused by the intense water flow.
For longer roof sections, you may need to use multiple barrels. A short, sacrificial section of mini-gutter or a trough can be installed immediately above the barrel to concentrate the flow into a single stream. Alternatively, installing a metal flashing diverter directly under the fascia board can help guide the sheet flow of water into the barrel opening. Careful positioning ensures the majority of the water is captured.
Utilizing Auxiliary Water Diversion Systems
When the main house’s eaves are unsuitable for direct collection, harvesting water from smaller, detached structures is a useful alternative. Sheds, garages, or workshops often have simple roofs that serve as excellent catchment surfaces. The collected water can then be used for gardens located further from the home, and the setup follows the same principle: placing the barrel directly under the most active drip line.
Temporary funnel systems can also be employed to direct rainfall into the barrel. One simple method involves securing a large, waterproof tarp and angling it so that all runoff flows toward a single, low point. The tarp’s corner or a small hole punched in the center can be positioned directly above the barrel’s screened inlet, creating a vast, temporary catchment surface.
A more structured approach involves constructing a “butterfly” or V-shaped diversion system from two rigid, sloped surfaces. This structure acts as a large, custom-built funnel, directing water down a sealed midline and into the barrel. Commercial rain chains or specialized diverters, often designed for downspouts, can be adapted to guide water from the roof fascia. They capture runoff closer to the building and slow the water’s descent into the container.