Quick Answer
Cisterns are more effective than rain barrels for long-term water storage, as they can hold significantly larger volumes of water, often in the thousands of gallons, making them ideal for larger homes or gardens with high water demands.
Cistern Design and Sizing
When designing a cistern, it’s essential to consider the roof size and the local rainfall pattern. A general rule of thumb is to size the cistern to capture 1-2 inches of rainfall per hour from the roof area. For example, a 1,000 square foot roof with a 1:12 slope can be expected to collect around 450 gallons of rainwater per hour. To calculate the cistern size, multiply the roof area by the expected rainfall depth and the desired collection period. For a typical suburban home, a 5,000-gallon cistern can provide several months of water supply during dry periods.
Rain Barrel vs. Cistern Water Quality
While rain barrels can be effective for small-scale water collection, they often require more frequent maintenance and are more prone to contamination due to their smaller size and open-top design. Cisterns, on the other hand, can be designed with a floating intake system, which draws water from the top 1-2 feet of water, reducing the risk of contamination from sediment and debris. This design also helps to protect the cistern from mosquito breeding and other pests. Additionally, cisterns can be equipped with sedimentation chambers and other treatment systems to improve water quality.
Maintenance and Upkeep
Regular maintenance is crucial to ensure the effectiveness and longevity of both cisterns and rain barrels. Cisterns should be inspected annually for signs of damage, corrosion, or contamination, and cleaned as needed. Rain barrels require more frequent cleaning and maintenance, as they are more prone to clogging and contamination. By understanding the unique needs and limitations of each system, homeowners can make informed decisions about which option is best suited for their specific needs and circumstances.
Find more answers
Browse the full Q&A library by topic, or jump back to the topic this question belongs to.