5 Best Storage Tanks for Rainwater Harvesting That Boost Self-Sufficiency

Capturing and storing rainwater isn’t just environmentally conscious—it’s a smart investment that can significantly reduce your water bills while creating a sustainable water source for your garden and home. Rainwater harvesting systems rely on quality storage tanks that determine how effectively you’ll collect and maintain this valuable resource. Choosing the right tank depends on your specific needs, available space, and budget constraints.

When selecting from the numerous options available, factors like durability, capacity, and material composition should guide your decision-making process. The perfect rainwater storage solution balances functionality with practicality while complementing your property’s aesthetic. Let’s explore the five best storage tanks that deliver exceptional performance for rainwater harvesting enthusiasts.

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5 Best Storage Tanks for Rainwater Harvesting

Polyethylene Rain Barrels: Affordable and Versatile Solutions

Polyethylene rain barrels offer the most cost-effective entry point into rainwater harvesting. These lightweight tanks come in various sizes, from compact 50-gallon barrels to expansive 300-gallon systems like the Snyder Water Storage Tank. Their UV-inhibited construction prevents degradation from sun exposure while resisting rust, corrosion, and impact damage, making them ideal for beginners and experienced harvesters alike.

Galvanized Steel Cisterns: Durable and Long-Lasting Options

Galvanized steel cisterns provide exceptional longevity and strength for serious rainwater collectors. These robust tanks feature corrosion-resistant coatings that protect against the elements, ensuring decades of reliable service. Steel cisterns can be installed both above and below ground, adapting to various property configurations while maintaining structural integrity even in challenging environments or when storing large water volumes.

Concrete Storage Tanks: Heavy-Duty and Underground Capabilities

Concrete storage tanks excel in situations requiring maximum durability and underground installation. These heavy-duty systems can be customized to exact specifications, supporting large-scale rainwater collection needs of 1,000+ gallons. Their solid construction withstands significant soil pressure when buried, making them virtually permanent installations that require minimal maintenance while providing decades of reliable water storage capacity.

Fiberglass Rainwater Collectors: Lightweight yet Robust Alternatives

Fiberglass rainwater collectors balance impressive strength with manageable weight for easier installation. These tanks resist corrosion, chemicals, and UV damage while maintaining structural integrity year after year. Their smooth interior surfaces prevent algae growth and simplify cleaning maintenance, while their natural insulating properties help maintain consistent water temperatures throughout seasonal changes, protecting your harvested rainwater from freezing or overheating.

Flexible Bladder Tanks: Space-Saving Storage Solutions

Flexible bladder tanks revolutionize rainwater storage for properties with limited space or awkward configurations. These innovative systems expand as they fill and contract when empty, fitting underneath decks, in crawl spaces, or other tight areas conventional tanks cannot access. Made from durable, food-grade materials, bladder tanks offer surprising capacity (up to several hundred gallons) while remaining virtually invisible when integrated into existing structures.

Key Features to Consider When Choosing a Rainwater Storage Tank

When selecting the perfect rainwater storage tank for your harvesting system, several critical features will determine its effectiveness and longevity. Here are the key aspects you should evaluate before making your purchase:

Capacity and Size Requirements

Your tank’s capacity should match your water needs and available rainfall. A small garden might only require a 100-gallon Bushman tank ($462), while larger properties benefit from 1000+ gallon options like the Snyder 2000 Gallon ($2,070). Consider your space limitations and anticipated usage patterns—landscaping demands more capacity than occasional garden watering. Always calculate based on your region’s rainfall patterns and dry periods.

Material Durability and Maintenance Needs

Polyethylene tanks from manufacturers like Poly-Mart and Norwesco offer excellent durability with built-in UV inhibitors to prevent sun damage. These tanks resist rust, corrosion, and impact, ensuring longer lifespans whether placed indoors or outdoors. Bushman tanks come in various colors (black, dark green, dark brown, mocha) and require minimal maintenance, making them practical long-term investments for any rainwater harvesting system.

Installation Complexity and Placement Options

Above-ground tanks from Snyder and Bushman offer simpler, more cost-effective installation with pre-installed lids and outlets. Underground options provide aesthetic benefits but require more extensive planning and installation work. Consider your property’s layout—slimline tanks work well in narrow spaces, while larger cylindrical models need more open areas. Factor in accessibility for maintenance, proximity to downspouts, and whether you’ll need additional features like pre-tank filtration or level gauges.

How to Properly Install Your Rainwater Harvesting Tank

1. Assess the Roof Surface

Determining your roof’s suitability is the first crucial step in rainwater harvesting installation. Use a rainwater calculator to estimate collection potential based on your roof size and local rainfall patterns. Smooth, non-toxic surfaces like metal or clay tiles typically provide the cleanest water compared to asphalt shingles that may leach chemicals.

2. Install Gutter Mesh and Outlets

Proper gutter protection prevents debris from entering your system and causing blockages. Install quality gutter mesh like Blue Mountain Mesh® to keep leaves and twigs out while allowing water to flow freely. Fit gutter outlets from underneath to ensure smooth water flow and maximum collection efficiency.

3. Use Leaf Eater or Leaf Beater Rain Heads

Rain heads serve as your system’s first line of defense against contamination. Install Leaf Eater® or Leaf Beater® devices on all downpipes to prevent debris from entering the tank system. These specialized components also create a physical barrier against mosquitoes and other pests that might try to access your water supply.

4. Install First Flush Diverter

First flush diverters significantly improve your harvested water quality by preventing initial contaminated runoff from entering your tank. These devices automatically divert the first few gallons of rainfall that typically contain the highest concentration of roof contaminants. Position diverters on each downspout connected to your collection system for optimal results.

5. Screen the Tank Entry

Proper screening at the tank entry point creates an essential secondary barrier against contamination. Install fine mesh screens where water enters your tank to catch any debris that might have bypassed earlier filtration steps. This screening also prevents mosquitoes from breeding in your stored water, protecting both water quality and family health.

6. Choose the Right Tank Size

Selecting appropriate tank capacity ensures you maximize collection potential without wasting space or resources. Base your tank size on three key factors: annual rainfall in your area, available roof catchment area, and your household’s water usage needs. Remember that larger isn’t always better—the ideal tank balances collection potential with practical space considerations.

7. Attach Insect Proof Screens and Flap Valves

Complete pest protection requires securing all potential entry points to your tank. Attach insect-proof screens or flap valves to every pipe connected to your tank system. These protective measures prevent mosquito breeding while ensuring proper ventilation and overflow functionality.

8. Install an Air Gap to Tank Overflow Outlets

An air gap between your tank overflow and drainage system prevents potential contamination through backflow. Install this critical separation point where your overflow connects to stormwater systems. This simple measure protects your clean harvested water from contamination during heavy rain events when stormwater systems may become pressurized.

9. Utilize a Tank Top-Up System (if required)

Automatic top-up systems provide peace of mind during dry periods when rainwater supplies run low. These systems monitor water levels and automatically supplement your tank with municipal water when levels fall below a designated minimum. Install with appropriate backflow prevention devices to meet local plumbing codes.

10. Select a Pump System (if required)

The right pump ensures reliable water pressure for your intended applications. Choose a pump system based on your specific needs—garden irrigation requires different specifications than whole-house supply. Position pumps on level, stable surfaces with appropriate weatherproofing and electrical safety measures in place.

11. Install Rainwater Filters

Final filtration polishes your harvested water for optimal quality and usability. Fit purpose-designed rainwater filters after the pump to reduce any remaining sediment, color, or odor. For potable applications, invest in multi-stage filtration systems that include UV treatment to ensure water meets safety standards.

Maintaining Your Rainwater Storage System for Maximum Efficiency

Pre-Tank Filtration

Pre-tank filtration is essential for keeping your rainwater clean and your system functioning properly. Install filter screens at your gutters and downspouts to prevent leaves, twigs, and other debris from entering your storage tank. First flush diverters are particularly effective as they redirect the initial rainfall (which contains the most contaminants) away from your storage system. Regular inspection of these filters ensures they’re not clogged or damaged, which could compromise water quality.

Regular Cleaning

Your rainwater harvesting system requires consistent maintenance to operate at peak efficiency. Clean your roof catchment area at least twice a year, removing accumulated debris, moss, and bird droppings that could contaminate your water supply. Flush your gutters and downspouts seasonally to prevent blockages that reduce collection efficiency. For optimal results, schedule major cleanings before the rainy season starts in your region to maximize collection potential.

Tank Inspection

Routine tank inspections prevent small issues from becoming costly problems. Check your storage tanks quarterly for cracks, leaks, or signs of damage, especially after extreme weather events. Inspect all connections, fittings, and seals to ensure they remain watertight and secure. Look for signs of algae growth or sediment buildup inside the tank, which may indicate that your filtration system needs attention. Document each inspection to track changes or developing issues over time.

Water Sanitization

If you’re using harvested rainwater for potable purposes, proper sanitization is non-negotiable. UV treatment systems effectively neutralize harmful microorganisms without adding chemicals to your water. Alternatively, chlorination using food-grade bleach (at a ratio of 1/8 teaspoon per gallon of water) can disinfect stored rainwater. For non-potable uses like irrigation, consider simple filtration methods that remove particulates without full sanitization. Test your water quality regularly to ensure your treatment methods are working effectively.

Level Gauges and Monitoring

Installing water level indicators gives you valuable data about your system’s performance. Modern digital gauges can provide real-time monitoring accessible from your smartphone, allowing you to track water usage patterns and collection efficiency. This information helps identify potential leaks when water levels drop unexpectedly or overflow risks during heavy rainfall periods. Some advanced systems even integrate with weather forecasts to help optimize water usage based on upcoming precipitation predictions.

Aesthetic and Functional Considerations

Balance practical needs with visual appeal when positioning your rainwater storage system. Underground tanks offer excellent aesthetic benefits by remaining hidden from view while providing stable water temperatures and protection from UV damage. For above-ground tanks in visible locations, consider decorative screens, trellises with climbing plants, or custom paint finishes that complement your property. Remember that tank accessibility remains critical for maintenance regardless of placement decisions.

UV Protection

UV damage significantly reduces the lifespan of plastic storage tanks. Choose tanks with built-in UV inhibitors or apply UV-resistant coatings to existing tanks to prevent deterioration and cracking. Position vulnerable tanks in shaded areas whenever possible to minimize direct sunlight exposure. For added protection, consider installing sun shields or canopies over exposed tanks, which has the added benefit of reducing algae growth by limiting light penetration. Check manufacturer specifications for the expected UV resistance rating of your particular tank.

Conclusion: Making the Right Choice for Your Rainwater Harvesting Needs

Selecting the perfect rainwater storage tank is a crucial step toward sustainable water management. Whether you opt for versatile polyethylene barrels durable galvanized steel cisterns heavy-duty concrete tanks lightweight fiberglass collectors or space-saving bladder systems your choice should align with your specific needs.

Remember to consider capacity material durability maintenance requirements and installation complexity as you make your decision. A properly installed and maintained rainwater harvesting system isn’t just environmentally responsible—it’s a smart financial investment that can boost your property value and provide reliable water for years to come.

By implementing the installation and maintenance tips outlined above you’ll maximize efficiency and extend the life of your system. Your journey toward water independence starts with choosing the right tank—make it count.

Frequently Asked Questions

What are the benefits of rainwater harvesting?

Rainwater harvesting offers multiple benefits including reducing water bills by 30-50% annually, decreasing demand on municipal water supplies, preventing erosion and flooding, and providing a sustainable water source for gardens. It can increase property value by 3-7%, appeal to eco-conscious buyers, and enhance disaster preparedness by ensuring access to water during emergencies or service disruptions.

How much money can I save with a rainwater harvesting system?

A properly installed rainwater harvesting system can reduce water bills by 30-50% annually. The initial investment typically pays for itself within 2-5 years, especially when taking advantage of available tax incentives. Additionally, homes with these systems may see an increase in property value by 3-7%.

What are the best storage tanks for rainwater collection?

The five best rainwater storage options are: 1) Polyethylene Rain Barrels – affordable and UV-resistant; 2) Galvanized Steel Cisterns – durable and corrosion-resistant; 3) Concrete Storage Tanks – ideal for underground installation; 4) Fiberglass Rainwater Collectors – lightweight with algae prevention; and 5) Flexible Bladder Tanks – space-saving solutions that expand as needed.

How do I choose the right size rainwater tank?

Select your tank size based on your water needs and local rainfall patterns. Consider your roof collection area, average rainfall in your region, and intended water usage (garden only vs. household use). Larger capacity systems provide more consistent supply during dry periods, but ensure your space can accommodate the tank dimensions.

Is rainwater good for gardening?

Yes, rainwater is excellent for gardening. It’s naturally soft and free from chemicals like chlorine found in municipal water, promoting healthier plant growth. Rainwater helps maintain soil quality and pH balance, making nutrients more accessible to plants. Using harvested rainwater for gardens also reduces demand on treated water supplies, making it environmentally beneficial.

What maintenance does a rainwater harvesting system require?

Maintenance includes regular gutter cleaning, checking pre-tank filtration systems, and inspecting tanks annually for cracks or leaks. Clean tanks every 2-3 years to remove sediment. If using water for drinking, sanitize via UV treatment or chlorination. Install water level indicators to monitor system performance and ensure UV protection for plastic tanks to prevent degradation.

Do I need a permit to install a rainwater harvesting system?

Permit requirements vary by location. Some municipalities require permits for large systems or those connected to household plumbing. Others offer incentives for installation. Check with local building departments, water authorities, or homeowners associations before installation. Some regions with water scarcity may have specific regulations governing rainwater collection systems.

Can harvested rainwater be used for drinking?

Yes, harvested rainwater can be made potable with proper treatment. This requires a comprehensive filtration system including sediment filters, activated carbon filters, and UV disinfection or chlorination. Regular water quality testing is essential. Many jurisdictions have specific regulations for potable rainwater systems, so check local health department guidelines before using for drinking water.