The Best Way to Store Water Long Term

By Nate Baker

The short answer is that the best way to store water long-term is in rotationally-molded plastic water storage tanks. There are some very important reasons why roto-molding matters, and we'll cover that.

Why Long-Term Water Storage Matters

Clean water is the foundation of emergency preparedness. Natural disasters, infrastructure failures, and contamination events can interrupt your water supply with no warning. Long-term water storage helps you stay self-reliant during these disruptions, ensuring your family has safe drinking water, sanitation water, and cooking water when you need it most.

The Best Containers for Long-Term Water Storage

Rotationally Molded Tanks vs. Cheap Alternatives

Rotationally molded (roto-molded) tanks are the gold standard for long-term water storage. Unlike thin, blow-molded barrels, roto-molded tanks have uniform wall thickness—even in the corners—and are significantly more impact-resistant. This rugged construction is why the same plastic is used for chemical storage, septic tanks, and even crash barriers.

Cheap containers like reused soda bottles or milk jugs break down quickly, leach chemicals, and often fail without warning. For multi-year reliability, dedicated water storage tanks are the safest and most durable solution.

Why Food-Grade Plastic Is Ideal

Food-grade, BPA-free plastic is engineered to prevent chemical leaching, resist UV degradation, and preserve water purity over long periods of storage. Water tanks made from FDA-approved polyethylene won’t impart taste or odor into your water and remain stable in changing environmental conditions.

All Emergency Water Tanks products use food-grade, rotationally molded HDPE for maximum safety and longevity.

How to Prepare Water for Long-Term Storage

  • Use treated, municipal drinking water when possible—it's already chlorinated and ready for storage.
  • If storing well water or untreated water, use a long-term water treatment solution (like 5-year treatment drops).
  • Clean and sanitize tanks before filling using a mild bleach solution (1 tsp of unscented bleach per quart of water).
  • Fill completely to reduce oxygen exposure and minimize bacterial growth.

Where and How to Store Your Water Safely

We recommend storing water in our stackable water storage tanks. We have two sizes, and also a doorway tank option. All of our tanks are built to last through rotomolding. And you don't need a pump to get the water out!

Temperature, Light & Placement Guidelines

  • Keep water out of direct sunlight to prevent algae growth and slow plastic degradation.
  • Store in a cool location, ideally 50–70°F.
  • Avoid garages or sheds if temperatures regularly exceed 120°F.
  • Place tanks on a flat, stable surface to prevent stress on fittings.

How to Use Stackable Tanks for Space Efficiency

Stackable water tanks—such as 30-gallon and 55-gallon stackable units—let you store more water in small spaces without compromising stability. These tanks lock into place and include bottom spigots, allowing you to dispense water without pumps or siphons.

The 300-gallon doorway tank fits through standard doorways, making it perfect for indoor placement where temperatures are controlled.

How Long Water Lasts in Storage (and When to Replace It)

Properly stored water can remain safe indefinitely, but freshness and taste improve with rotation.

  • Untreated stored water: Replace every 6–12 months (Learn more about how long water lasts).
  • Treated with long-term water preservers: Lasts up to 5 years without rotation.
  • Commercially bottled water: Typically 1–2 years (manufacturer guidelines).

Inspect tanks periodically for odors, discoloration, or algae growth. Learn more about how to store water long-term.

Best Practices for Maintenance & Inspection

  • Check spigots and fittings for leaks.
  • Sanitize the tank after every full refill.
  • Keep tanks covered and protected from temperature extremes.
  • Use only potable water hoses when filling.

Frequently Asked Questions

Can I store water in milk jugs? No. They degrade quickly and frequently leak.

Do I need to rotate water stored in Emergency Water Tanks? If treated, water can remain fresh up to 5 years; untreated water should be rotated yearly.

Is a pump required? No—our tanks include bottom spigots for gravity-fed dispensing.

You can learn more about safe water storage with the CDC.

Other helpful resources:

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