Quick Answer
With proper maintenance, water from a rain barrel can be stored for up to 6 months. However, factors like temperature, amount of sunlight exposure, and debris can impact how long rain barrel water will last before needing to be emptied. Generally, rain barrel water should be emptied and refilled every 2-3 months for best quality.
How Does a Rain Barrel Work?
A rain barrel is a container that collects and stores rainwater from downspouts that drain rainwater from rooftops. The rain barrel is typically connected to the downspout either directly or through a diverter. As rain flows through the downspout, it will fill up the rain barrel rather than drain onto the ground. A rain barrel has an opening at the top where water flows in from the downspout, and a spigot near the bottom where the collected rainwater can be drained for use.
Benefits of Using a Rain Barrel
There are several advantages to using a rain barrel:
- Provides a free source of water – Collecting rainwater eliminates the need to use tap water for some outdoor purposes like watering plants.
- Reduces runoff and erosion – By capturing rainwater, less water flows into storm drains and streams which can cause erosion and pollution.
- Saves money on water bills – Using rain barrel water for gardening, washing cars, etc. reduces outdoor tap water usage.
- Good for plants – Rainwater is free of chemicals, salts, and other minerals found in tap water which can build up in soil over time.
- Emergency water supply – Stored rainwater provides a backup supply for essential needs during periods of drought or main water shutoffs.
Factors That Determine How Long Rain Barrel Water Will Last
There are several variables that impact how long collected rainwater will stay fresh and safe to use in a rain barrel:
1. Temperature
Warmer temperatures speed up microorganism growth which can contaminate rain barrel water over time. Cooler temperatures help slow down the rate at which microbes multiply. During hot summer months, rain barrel water may need to be emptied and refreshed more frequently than in cool weather.
2. Sunlight Exposure
Direct sunlight exposure also accelerates microbe and algae growth in stored water. Rain barrels should be placed in shaded areas or covered to help block sunlight. UV rays in sunlight can also break down plastic barrels more quickly.
3. Debris
Screening on rain barrel lids keeps out leaves, dust, and other debris that can accumulate in the barrel. But small organic matter may still enter the water, adding nutrients for microorganism growth. Frequently cleaning out debris improves water quality.
4. Rain Barrel Setup & Maintenance
Proper setup and maintenance makes a big difference in how long collected rainwater stays fresh. Keeping connection points secure, screening vents, sealing cracks, and periodically disinfecting the barrel all help maximize water lifespan.
5. Local Climate & Air Quality
Areas with frequent rainfall versus infrequent, sporadic storms will impact usage and turnover of water in a rain barrel system. Local climate and air pollutants can also play a role in contaminant exposure.
How to Tell if Rain Barrel Water Has Gone Bad
Here are some signs that the quality of water in a rain barrel has declined and needs to be emptied:
– Cloudy appearance or changed color
– Algae visible on the sides and rim of the barrel
– Soft, slippery residue on surfaces the water touches
– Foul odors
– Bitter or unpleasant taste
– Mosquito larvae swimming in the barrel
If rainwater displays any of these characteristics, discontinue use and empty the rain barrel. Thoroughly clean and disinfect the barrel before refilling with fresh rainwater. Preventing stagnation by using rain barrel water regularly helps maintain water quality.
How Often Should You Empty A Rain Barrel?
During frequent year-round use, rain barrel water should be emptied and replenished every 2-3 months. This provides a regular refresh of the water to limit bacterial growth.
However, the ideal time frame can vary based on factors like:
– Temperature – During hot summer months, refresh rainwater every 4-6 weeks. In cooler weather, barrels may only need draining once a month.
– Local climate – In rainy climates with frequent rainfall, barrels can be emptied less often than drier areas.
– Debris/runoff – Heavy debris from trees or potential roof contaminants may require more frequent draining.
– Sun exposure – Barrels getting full sun exposure should be emptied more often than shaded barrels.
– Barrel maintenance – How often the barrel is cleaned and disinfected impacts water lifespan.
– Water appearance – If water becomes discolored, odorous, or contains visible contaminants, empty immediately.
During cold winter months when a rain barrel may be unused for weeks, completely drain and disconnect the system and leave open until spring.
How to Empty and Clean a Rain Barrel
Draining
Open the spigot at the bottom of the rain barrel and allow all water to empty out until container is completely dry.
Rinsing
Use a hose to rinse out any dirt or debris clinging to the inside walls of the barrel. A pressure washer can help blast out stubborn residue.
Disinfecting
Spray or scrub the interior with a bleach or vinegar solution. Let the cleaning solution sit for 10-15 minutes before rinsing thoroughly.
Debris Removal
Remove lid screen and clean out any debris like leaves or dust accumulated in the barrel.
Fixing Leaks
Inspect barrel seals for cracks and reapply silicone sealant anywhere rainwater could leak out.
Drainage
Leave spigot open and upside down to allow all remaining water drainage between rain events.
Thoroughly cleaning and draining the rain barrel between refills helps remove contaminants and prevents stagnation, maximizing the freshness of collected rainwater.
Can You Treat & Store Rain Barrel Water Longer?
While most rain barrel water gets used within a few months, there are methods to try to extend storage times:
Add filtration – Adding extra physical filters, sediment traps or an activated charcoal filter can help clean contaminants.
Limit light exposure – Tight-fitting lids and opaque barrels prevent sunlight from entering.
Control temperature – Storing barrels in cool, shaded areas avoids excess warmth.
Use water biocides – Liquid water treatments can control algae and microbes. Always follow product instructions carefully.
Reduce organic matter – Clean roof surfaces and gutters regularly to limit debris entering barrels.
Regularly maintain the system – Frequently clean, disinfect, and inspect barrels to optimize water quality.
However, while these methods help, they do not guarantee long-term rainwater storage. For optimal safety and quality, rain barrel water should be emptied and refilled every 2-3 months.
Long-Term Rainwater Collection Systems
For large-scale rainwater harvesting, more complex systems are needed to store and treat water for longer periods. Options include:
Rainwater cisterns – Underground tanks collect significantly more rain. Water may be treated with UV, filters, etc. Proper maintenance is still needed.
Well water – While not considered rainwater, wells access underground aquifers that are recharged by rainfall. Provides a consistent, renewable water source.
Municipal recycled water – Some communities now provide recycled wastewater treated to safe standards for non-potable uses.
For critical long-term water needs, professionals should be consulted to design an advanced rainwater harvesting system with proper storage capacity and treatment methods.
Conclusion
A properly maintained rain barrel can provide a free source of water for gardens, landscaping, and other outdoor uses during the growing season. But water quality deteriorates over time without regular draining and cleaning. For optimal safety and freshness, most experts recommend emptying and refilling a simple rain barrel every 2-3 months. With routine maintenance factored in, rain barrel water can be stored up to 6 months, avoiding potential contamination issues. Proper setup, drainage, debris exclusion, and disinfection helps maximize lifespan. Monitor water appearance and odor, draining immediately if any issues arise. While some methods may extend storage time slightly, large-scale rainwater collection requires advanced design and treatment systems. For simple backyard use, routinely flushing and restarting barrels every couple months provides a sustainable way to harness natural rainfall.
