A rain barrel is a simple, above-ground container designed to capture and store rainwater that drains from a roof through a downspout. These systems typically hold between 50 and 80 gallons of water, redirecting precipitation that would otherwise become runoff. Rain barrels offer homeowners tangible benefits related to water resource management and provide broader environmental advantages. Users gain access to a free supply of water for outdoor tasks.
Water Conservation and Utility Savings
Collecting rainwater significantly reduces a household’s reliance on municipal water systems, particularly during the dry summer months. Lawn and garden watering often accounts for up to 40% of total household water usage in the summer, making outdoor irrigation a major demand on potable supplies. By substituting collected rain for treated tap water, homeowners can effectively conserve this resource.
Utilizing rainwater directly translates into lower utility bills because less treated water is drawn from the municipal supply. The US Environmental Protection Agency suggests a single rain barrel can save a typical homeowner approximately 1,300 gallons of water during peak summer usage. Furthermore, using rainwater helps lessen the burden on local water treatment facilities, reducing the energy required for purification and distribution.
Managing Stormwater Runoff
Rain barrels serve a significant environmental function by mitigating the effects of stormwater runoff on local infrastructure and ecology. During heavy rainfall, impervious surfaces like roofs, driveways, and sidewalks prevent water from soaking into the ground, leading to a rapid increase in surface flow. This overwhelming volume can flood residential areas and overload municipal storm sewer systems.
By capturing and temporarily holding dozens of gallons of water, a rain barrel reduces the sudden surge entering the drainage system. This action helps prevent localized flooding and minimizes soil erosion around a home’s foundation.
Stormwater runoff is also a primary source of non-point source pollution, carrying contaminants like oil, pesticides, fertilizers, and sediment directly into local streams and rivers. By intercepting the flow, rain barrels diminish the amount of polluted water that reaches natural waterways, protecting aquatic habitats from excess nutrients and bacteria.
Uses for Collected Water
The collected rainwater is intended for non-potable uses and should not be used for drinking, cooking, or bathing. The most common application is outdoor irrigation, including watering flower gardens, lawns, and container plants. Plants often benefit from rainwater because it is naturally soft, contains atmospheric nitrates, and is free of the chlorine and fluoride compounds commonly added to municipal tap water.
The absence of these chemicals helps sensitive plants thrive and supports the soil microbiome. Beyond gardening, stored water can be used for various household chores:
- Washing cars
- Cleaning outdoor tools
- Refilling ornamental ponds
- Hosing down patio furniture
If the collected water exceeds immediate needs, it should be drained slowly onto a lawn or landscaped area to allow it to seep naturally into the ground.
Basic System Components and Water Quality
A functional rain barrel system involves several components designed to maximize collection efficiency and address safety concerns. The barrel features a connection point, often a downspout diverter, to channel water from the gutter into the container. A spigot or faucet near the bottom allows for controlled dispensing of the stored water into watering cans or hoses.
A mesh screen or tight-fitting lid is necessary at the inlet to prevent debris from entering and to seal the water from insects. This screening is important for preventing mosquitoes from laying eggs in the standing water. If larvae are detected, the water can be treated with a biological larvicide like Bacillus thuringiensis israelensis (Bti), which is safe for plants and wildlife. Because the water runs off a roof, it may contain trace contaminants like bacteria, bird droppings, or particles from the roofing material.