A rain barrel is a simple collection system designed to capture and store rainwater runoff, typically from a home’s rooftop via its gutter and downspout network. The primary function of this system is water conservation, providing a readily available supply of non-potable water for household and garden use. Harvesting rainwater reduces the demand on municipal water supplies and mitigates stormwater runoff, which can carry pollutants into local waterways. The basic mechanism involves diverting the natural flow of water into a secure storage container for later retrieval.
Anatomy of the Rain Barrel and Collection Flow
The rain barrel system relies on several integrated components to manage the flow of water from the roof into storage. Water travels from the roof into the gutters and then down the vertical downspout, where it encounters the downspout diverter. The diverter is a mechanical device installed into a cut section of the downspout, designed to channel water horizontally into the barrel. A connector hose links the diverter to the barrel’s inlet, which is typically protected by a fine mesh screen.
This screen prevents leaves, large debris, and insects from entering the stored water, which helps maintain water quality. The main barrel serves as the storage reservoir, commonly holding between 50 and 80 gallons of water. Once the water level rises to the height of the diverter connection point, the flow automatically stops entering the barrel.
Subsequent rainwater is then redirected back down the downspout’s original path, safely bypassing the full barrel to prevent overflow near the foundation. For water retrieval, a spigot is installed near the bottom of the barrel, and an overflow port near the top allows excess water to be channeled away from the home via a separate hose.
Installation and Downspout Diversion
Proper installation begins with selecting a sturdy and level location for the barrel, preferably near a downspout that handles significant roof runoff. Since a full 55-gallon barrel weighs over 450 pounds, a stable foundation is necessary to prevent tipping or sinking. The barrel should be elevated slightly, often placed on a platform of concrete blocks or bricks, to create enough height for gravity to provide adequate water pressure when using the spigot.
Connecting the system requires cutting the downspout to insert the diverter mechanism. A precise section of the downspout is removed, and the diverter is positioned so its outlet connection is level with or slightly below the barrel’s inlet port to ensure optimal water flow. Once the diverter is secured, the connector hose is run to the barrel inlet. This setup ensures efficient water flow and correct overflow mechanism function when the barrel is full. The remaining section of the downspout is reattached below the diverter to guide bypass water away from the structure’s foundation.
Seasonal Maintenance and Water Usage
Regular maintenance is necessary for the barrel system to function effectively and safely across different seasons. During warmer months, the primary concern is preventing mosquito breeding, as standing water provides an ideal habitat. All openings must be sealed with fine mesh screening to block adult mosquitoes from laying eggs.
If mosquitoes bypass the screens, a biological larvicide containing Bacillus thuringiensis israelensis (Bti) can be added to the water. Bti is a naturally occurring bacterium toxic only to the larvae of mosquitoes and black flies when ingested, making it safe for use on food crops and around pets. Periodic cleaning of the barrel interior is also recommended to remove sediment accumulation, which should be drained away from the home’s foundation.
Before the first hard freeze, the system must be winterized to prevent damage from expanding ice. This involves completely draining the barrel and disconnecting the downspout diverter. The empty barrel should be stored in a protected area or turned upside down to prevent water collection. A winter cap is then placed over the downspout opening to restore the original water path and direct runoff away from the home until spring.
The collected rainwater is considered non-potable and is intended for outdoor applications that do not involve consumption. Water is retrieved either by gravity feed through the spigot or by connecting a small electric pump for applications requiring higher water pressure. Common uses include:
- Watering ornamental plants, vegetable gardens, and lawns.
- Washing vehicles.
- Cleaning tools.
- Rinsing off patios.