How to Store Water Long Term

When emergencies strike, nothing is more important—or more overlooked—than clean drinking water. Whether you're preparing for natural disasters, supply disruptions, or off-grid living, long-term water storage gives you peace of mind with every gallon. This guide walks you through what to store, how to store it, and how long stored water actually lasts.

Why Long-Term Water Storage Matters

A family can survive weeks without food—but only 3 days without water. Disasters can contaminate tap water, damage infrastructure, or interrupt delivery systems. Long-term water storage ensures you stay self-reliant, safe, and hydrated no matter what happens.

How Much Emergency Water Do You Actually Need?

FEMA Guidelines

  • infographic depicting you should plan for 14 days of water and 2-3 gallons per person for emergency water storage
    Minimum: 1 gallon per person, per day
  • Recommended supply: At least 14 days (many experts suggest 30)

Learn more.

Adjusting for Family Size, Climate, and Special Needs

  • You live in a hot climate (sweat loss increases consumption)
  • You have infants, elderly family members, or medical needs
  • You need water for pets, cooking, or sanitation
  • You’re preparing for off-grid or rural living

A realistic emergency target for most families: 2–3 gallons per person per day.

Choosing the Right Water Storage Containers

Why Food-Grade Plastic Matters

Only store water in food-grade, BPA-free containers. These materials keep your water clean, safe, and free from chemical leaching.

Rotationally Molded vs. Blow-Molded Tanks

At Emergency Water Tanks, we use rotationally molded plastic, which means:

  • Uniform wall thickness
  • No weak corners or edges (unlike blow-molded tanks)
  • Increased structural strength for long-term storage

This is the same process trusted for heavy-duty chemical storage—ideal for safe drinking water.

Best Tank Sizes for Homes, Apartments, and Campsites

You can find the right water storage container here at Emergency Water Tanks:

How to Store Water Long Term (Step-by-Step)

1. Clean and Prepare Your Containers

Wash with:

  • Unscented dish soap
  • Warm water
  • A sanitizing solution (1 tsp household bleach per quart of water)

Rinse completely before filling.

infographic showing the 4 steps how to store water long term

2. Fill Tanks Safely

Use potable (drinking-quality) water from:

  • Municipal tap sources
  • Certified well systems
  • Water treated with filtration or purification

3. Add Water Treatment

For long-term storage (up to 5 years), use a professional-grade water treatment, such as our solution formulated specifically for 55-gallon tanks. This prevents bacterial growth and eliminates the need for annual rotation.

4. Choose the Right Storage Location

Store tanks:

  • Indoors or in shaded, temperature-stable areas
  • Away from chemicals or fumes
  • On level, supportive flooring

Avoid direct sunlight, which can increase algae growth.

How Long Can Water Be Stored?

Expected Shelf Life

  • Untreated tap water: 6–12 months
  • Treated and properly stored water: Up to 5 years
  • Commercially sealed water: Follow manufacturer dates

Water itself doesn’t “expire,” but storage conditions impact taste and safety.

infographic showing how long different types of water treatments are supposed to last

Signs Your Water Needs to Be Replaced

  • Cloudiness
  • Algae or sediment
  • Unusual taste or smell
  • Container damage or leaks

When in doubt, purify or replace.

Maintenance and Rotation Tips

Inspect Your Tanks

Check every 6–12 months for:

  • Cracks
  • Leaks
  • Bulging
  • Discoloration

When (and How) to Rotate

If using untreated tap water:

  • Rotate annually
  • Use old water for plants, cleaning, or flushing
  • Refill with fresh treated water

Rotationally molded tanks include bottom spigots, making emptying easy—no pump required.

Best Containers for Long-Term Water Storage

30-Gallon Stackable Tanks

Perfect for smaller homes and tight spaces. Stackable design lets you store more water vertically.

55-Gallon Stackable Tanks

A larger capacity option that still fits well in garages or utility rooms.

300-Gallon Doorway Tanks

High-capacity storage designed to fit through standard doorways. Ideal for families, farms, and facilities.

All Emergency Water Tanks products are:

  • Rotationally molded
  • BPA-free & UV-resistant
  • Made in the USA
  • Built for decades of reliable water storage

Final Safety Tips and Common Mistakes to Avoid

Avoid:

  • Storing water in milk jugs
  • Using non-food-grade plastics
  • Leaving tanks in hot attics or direct sunlight
  • Forgetting to treat or rotate your water

Do:

  • Label tanks with fill dates
  • Store water in a temperature-stable environment
  • Use proper treatment to extend shelf life
  • Choose rugged, stackable, long-term tanks
Back to blog