Water Storage

3 Underground Water Storage Tanks: Pros, Limits and Options in 2026

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A round cistern lid set into a green lawn

The short answer

Underground water storage tanks keep water cool, dark and out of sight, but they cost more to install. For most emergency plans, above-ground tanks and barrels are simpler.

Last updated September 2026

Contents8

Our top 3 picks

  1. 1Best simple in-ground option for irrigationIn-Ground Rainwater Storage TankView at eBayRead our analysis
  2. 2Best above-ground alternative for drinking waterElkhart Plastics 1000-Gallon Vertical TankView at eBayRead our analysis
  3. 3Best mid-size above-ground alternativeRomoTech 550-Gallon Tank with LegsView at eBayRead our analysis

Underground water storage tanks, also called cisterns, hold water below the ground. The EPA notes that cisterns used to harvest rain water can sit above or below ground. Buried tanks keep water cool and dark and free up yard space. They also cost more and take more work to install.

#1. In-Ground Rainwater Tank: best simple in-ground option for irrigation

In-Ground Rainwater Storage Tank

Our verdict:

Best simple in-ground option for irrigation

Best for garden and livestock water.

View at eBay

Keep in mind: it is aimed at irrigation, not drinking water. The listing also gives mixed sizes, so confirm the capacity on the page.

#2. Elkhart Plastics 1000-Gallon Tank: best above-ground alternative for drinking water

#3. RomoTech 550-Gallon Tank with Legs: best mid-size above-ground alternative

Factors to consider when choosing an underground water storage tank

Few true underground tanks ship as a simple buy. Most are installed by a contractor. We picked one in-ground option and two above-ground tanks that often make more sense for home emergency water. We used the EPA's rain barrel and cistern page and Ready.gov's water page. Check each listing before you buy.

Underground vs above-ground tanks

Underground tanks:

  • Keep water cool and dark, which slows algae.
  • Save yard space and stay out of sight.
  • Need digging, a burial-rated tank and a pump.
  • Are harder to inspect and repair.

Above-ground tanks:

  • Cost less and install faster.
  • Are easy to check and clean.
  • Take up space and need shade or a dark tank.

Installing underground water storage tanks

A buried tank is a building project. Call your local utility locator before you dig. Check local rules on tanks and rain collection. Use a tank rated for burial, set on a proper bed, and plan the inlet, overflow, vent and pump. Many homeowners hire a contractor for this.

Are underground water storage tanks worth it for emergencies

For most homes, no. A buried tank makes the most sense when you already plan a large rain collection system, or when yard space and looks matter a lot. For a short emergency, the goal is simpler: at least one gallon per person per day for several days, as Ready.gov advises. That fits in a few jugs or one barrel.

A buried tank also depends on a pump. If the pump runs on grid power, you may not reach the water in an outage. Plan a hand pump or backup power if the tank is part of your emergency plan.

Using stored rain water safely

The EPA notes that rain flowing over a roof can pick up bacteria and chemicals. Treat stored rain water as non-drinking water unless you filter and disinfect it. Keep a separate store of drinking water in food-grade containers. The water storage containers guide covers that, and the rain water barrel hub covers the full plan.

Questions people also ask

What are the benefits of underground water storage tanks?

They save yard space, keep water cool and dark, and are protected from wind and sun. They also stay out of sight.

Do underground tanks need a pump?

Usually, yes. Because the water sits below ground, you need a pump to bring it up for use.

Can I use any tank underground?

No. Only tanks built for burial can take the soil pressure. An above-ground tank can collapse if buried.