Above-ground tanks are faster to install in comparison to underground ones that call for more in-depth preparation. You’ll need these things to install the tanks, respectively: Above-ground: base prep, leveling, placement, and connection access Underground: excavation, backfilling, and underground piping Soil conditions and groundwater can significantly affect the complexity.

Access is the main difference between the two options. Above-ground tanks: You can see the above-ground tank easily, so it can be repaired faster by having full access to it. It is much easier to clean because you can simply drain the tank, remove the sediment, and dispose of it in an environmentally safe manner. Underground tanks: Underground tanks are more challenging to access. It is often more difficult to conduct inspections and maintenance. Their cleaning frequency is also less than above ground tanks and requires professional-use equipment for the evaluation itself.

Cost differences are largely driven by installation requirements. Above-ground tanks: Typically involve delivery, base preparation, and basic connections, making them relatively simpler and more cost-effective to install. Underground tanks: Require excavation, skilled labor, plumbing, backfilling, and site restoration, which significantly increases complexity and cost. Underground systems are typically not DIY-friendly and require specialized work

Choosing the Right Water Storage: Underground vs. Above-Ground Tanks Explained

Underground Water Storage Tanks vs Above-Ground Tanks: Which Fits Your Site?

The decision to either place the water storage tank underground or above the ground is largely dependent on the type of foundation, depth of burial, and soil preparation. This guide will help you choose the right setup based on a real-world application.

Uses for Water Storage Tanks

Water storage tanks are mainly installed to support supply management, reliability, and conservation. They are usually installed to bridge the gap between the supply and demand of water in daily life activities.

Potable Water Source

Generally, a water tank can be auxiliary or a stand-in for the main water supply if the groundwater is scarce or unreliable. Places that have limited water supply usually use water storage tanks to maintain a regular potable supply and a backup supply in case of outages.

Rainwater Harvesting

Rainwater harvesting means collecting rainwater from roofs and other paved areas. This water is then released as needed. It is often used in irrigation to minimize reliance on external water sources. This process also reduces soil erosion from runoff.

Fire Suppression and Sprinkler Reservoirs

Commercial and rural properties reserve water exclusively for fire-protection purposes. The firefighting water storage tanks carry a guaranteed volume of water readily available to a sprinkler system or for an emergency response.

Greywater

Greywater is referred to as lightly-used water, such as HVAC condensate or rainwater running off roofs. It's not meant for human consumption but could be used to irrigate forms of vegetation and to perform other types of activities that require non-potable water.

Agri-Business

The agricultural industry is heavily dependent on the ability to store water for animals and vegetation. Tanks for water storage guarantee a regular supply throughout the year and under different conditions, including times of extreme drought.

What is an Underground Storage Tank

An underground storage tank is a tank that has been placed below ground level, with a minimum of 10% of its total volume buried. These in-ground systems are used in spaces where space is limited or concealment is a matter of concern.

Underground Water Storage Tanks Pros and Cons

One of the key benefits of having your water storage tank underground is that it is not exposed to the elements. Because of this, they can remain at a consistent temperature throughout the year. But they need more installation planning and may be harder to access later.

Advantages of Underground Storage Tanks

Low profile
Maintain a steady temperature
Capacity potential

Low Profile

Since the tanks are placed underground, the land above will still be available for landscaping, parking vehicles, etc. With only access points and pipes exposed, the site can look good with less effort from the property owner.

Maintain a Steady Temperature

The soil acts as a natural insulator, so the temperature of underground water storage tanks will not fluctuate very much throughout the year. It is less likely to lead to freezing in the winters or become extremely hot in the summers.

Capacity Potential

Storing your tank underground also allows you to store far more water while taking up less space at ground level. This can be useful where above-ground height or space is restricted.

Disadvantages of Underground Water Tanks

Higher installation cost
Complex site preparation
Limited accessibility

Higher Cost

The installation will include excavation, support for the structure, back-filling, and restoring the installation site. If you add in other elements like pumps or piping, etc., those will also require additional labor and materials and, in turn, raise the overall cost.

Difficult to Maintain

Once installed, access is limited. Detecting cracks and leaks can become quite challenging. Moreover, the repairs might need excavation. If the soil has a lot of clay, it can also influence the effectiveness of the tank.

What Is an Above-Ground Water Storage Tank

A water storage tank that is completely above-grade level & 100% visible to the eye, is called an above-ground water storage tank, and this type of tank can be used for water harvesting, mostly because they provide easy access to the stored liquid & make installation of rainwater harvesting systems easy.

Above-Ground Storage Tanks Pros and Cons

Above-ground storage tanks are generally preferred for easier installation and maintenance, although these are also exposed to different conditions.

Advantages of Above-Ground Water Tanks

Easier access for inspection and repair
Lower installation complexity
Flexible placement options

Easier to Maintain

Since the aboveground tanks are fully visible, inspection is not a problem. Any signs of leaks, cracks, and faulty connections may be detected and addressed promptly and efficiently.

Aesthetics

Above-ground tanks may also be integrated using enclosures and different finishes for better aesthetics. Some properties also like to show off these tanks to demonstrate their efforts toward conservation.

Disadvantages of Above-Ground Water Storage Tanks

Exposure to temperature changes
Greater weather impact
Potential placement limitations

Difficult to Maintain Temperature

Water storage tanks above-ground get direct exposure to the elements. The contents of these tanks may become warm in the summer months, while in winter, there might be a need for some kind of protection against freezing, depending on the location.

Weather Damage and Physical Exposure

As a result of being in contact with the wind, sun, and external forces, above-ground tanks are at greater risk of developing leaks, which might only become noticeable after a period of time.

Leak Risk

Even though leaks are more visible in above-ground tanks, you need to take proper care of fittings.

Government and Other Regulations

Above-ground tanks may have to conform to zoning laws, which vary according to geographical location.

Capacity and Placement Limits

The size of an above-ground water tank may be restricted by available space, height restrictions, and other site constraints. Access clearance for installation and maintenance must also be considered.

Foundation First: What Placement Means for the Build

The decision on underground vs. above-ground tanks is taken on the basis of the foundation.

Foundation type: An above-ground water tank requires a solid foundation that must be stable and built from concrete. On the contrary, the foundation of underground water tanks will require excavation work.
Burial depth: Underground tanks have to be buried to a depth that is relevant to the soil conditions and the loads required.
Soil preparation: The soil conditions, drainage, and water level have a direct influence on the underground construction process and stability of the tank.

These conditions are far more important than the tank itself in construction costs and feasibility.

Installation, Maintenance, and Cost Comparison

The major difference in the installation, maintenance, and costs relates to the comfort of access to the tank over a period of time.

Installation

Above-ground tanks are faster to install in comparison to underground ones that call for more in-depth preparation. You’ll need these things to install the tanks, respectively:

Above-ground: base prep, leveling, placement, and connection access
Underground: excavation, backfilling, and underground piping

Soil conditions and groundwater can significantly affect the complexity.

Maintenance

Access is the main difference between the two options.

Above-ground tanks: You can see the above-ground tank easily, so it can be repaired faster by having full access to it. It is much easier to clean because you can simply drain the tank, remove the sediment, and dispose of it in an environmentally safe manner.
Underground tanks: Underground tanks are more challenging to access. It is often more difficult to conduct inspections and maintenance. Their cleaning frequency is also less than above ground tanks and requires professional-use equipment for the evaluation itself.

Cost

Cost differences are largely driven by installation requirements.

Above-ground tanks: Typically involve delivery, base preparation, and basic connections, making them relatively simpler and more cost-effective to install.
Underground tanks: Require excavation, skilled labor, plumbing, backfilling, and site restoration, which significantly increases complexity and cost.

Underground systems are typically not DIY-friendly and require specialized work

Choosing a Water Storage Tank

Selecting between underground and above-ground tanks comes down to how your site is built. Underground tanks are relevant in situations where space is limited and temperature control is a requirement, but they require more planning and effort. Above-ground tanks are far easier to install and maintain. In most cases, soil conditions, access, and overall foundation work will determine the final choice. Before making that decision, it helps to review the key site and planning factors below.

Available surface space
Desired tank visibility
Soil conditions and excavation feasibility
Burial depth constraints
Climate and freezing concerns
Installation requirements
Maintenance access preference
Budget and timeline
Local permitting expectations
Whether you may need a larger capacity now or later

Factor	Underground Tanks	Above-Ground Tanks
Surface Space	Minimal impact	Requires visible space
Visibility	Hidden	Visible
Soil Conditions	Critical factor	Less sensitive
Burial Depth	Required	Not applicable
Climate Considerations	More stable temperature	Exposed to the weather
Maintenance Access	Limited	Easy access
Budget and Timeline	Higher cost, longer install	Lower cost, faster install
Permitting	Often more complex	Site-dependent
Capacity Flexibility	Can support large volumes	Limited by footprint

Frequently Asked Questions

Underground water storage tanks are often preferred when surface space must be preserved. They allow the site to be used for other purposes while keeping storage concealed.

Difficult soil conditions, high levels of groundwater, and lack of excavation feasibility are some of the conditions that may make above-ground tanks a better solution.

Underground tanks are naturally insulated. However, above-ground tanks may also be considered if design considerations are made for the climate.

Placement is influenced when zoning, safety, or containment requirements apply. These vary by location and should be reviewed early in planning.

Soil conditions and site feasibility are the first things to consider. If site conditions are difficult and costly to excavate, above-ground tanks may be a better solution.