Installing an underground rainwater collection tank is a viable option for those looking to conserve space and protect their water supply. These tanks offer space efficiency, consistent water temperature, and aesthetic appeal.

However, they also come with higher installation costs and can be harder to access for maintenance. Understanding how to store rainwater underground, the durability of these tanks, and the shelf life of stored rainwater can help you make an informed decision.

Managing water resources efficiently is important, especially in areas prone to water scarcity. Many homeowners seek effective solutions for rainwater harvesting. However, determining whether to install a rainwater tank above ground or underground can be challenging.

This guide will explain the feasibility and benefits of installing an underground rainwater collection tank. By understanding these factors, you can decide whether an underground rainwater tank is right for you.

Can You Put A Rainwater Tank Underground?

Many homeowners install a rainwater collection tank underground to conserve space and protect their water supply. Underground tanks are typically made from durable materials such as concrete, polyethylene, or fiberglass and are designed to withstand the pressure from the surrounding soil.

Advantages of Underground Rainwater Collection Tanks

Underground rainwater collection tanks are increasingly popular for their ability to store large volumes of water while remaining out of sight. The following are the advantages of using these tanks:

Space Efficiency:

Maximized Yard Space: Underground tanks save valuable yard space, keeping your landscape open and uncluttered for other uses like gardening or recreation.
Flexible Landscaping: Allows for more creative and flexible landscaping options without accommodating a large above-ground tank.

Temperature Regulation:

Consistent Water Temperature: Being below ground helps maintain a consistent water temperature, reducing the risk of algae growth and ensuring better water quality.
Protection from Extremes: Underground tanks are insulated from extreme weather conditions, preventing water from freezing in winter or overheating in summer.

Aesthetic Appeal:

Hidden from View: Underground tanks do not interfere with the visual appearance of your property, maintaining the aesthetic integrity of your outdoor space.
Increased Property Value: Underground tanks can potentially increase property value and curb appeal by preserving the visual appeal of your yard.

Considerations for Underground Rainwater Collection Tanks

Similarly, when planning to install underground rainwater collection tanks, there are several important considerations to keep in mind. Below are some of them:

Installation Costs:

Excavation Required: Installing an underground tank can be more expensive due to the need for excavation and additional materials like gravel or concrete for stability.
Specialized Equipment: The installation process often requires specialized equipment and expertise, which can add to the overall cost.
Permits and Regulations: Depending on your location, you may need permits and inspections, which can also increase costs.

Access for Maintenance:

Challenging Access: While the tank is protected underground, accessing it for maintenance can be more challenging compared to above-ground tanks. Regular maintenance might require more effort and specialized tools.
Inspection Hatches: Ensure your underground tank has accessible inspection hatches to facilitate regular checks and maintenance tasks.
Pump Maintenance: Submersible pumps used in underground tanks are sealed and, if they fail, must be completely replaced, which can be a more complex and costly process.

How to Store Rainwater in Underground Tanks

Storing rainwater underground involves a few essential steps to ensure efficient collection and storage:

Choose the Right Tank: Select an underground tank, ensuring it’s made from durable materials to withstand underground conditions.
Excavate the Site: Dig a hole large enough to accommodate the tank, considering additional space for backfilling and proper drainage.
Install a Stable Base: Use gravel or a concrete slab to create a stable, level base that will support the tank and prevent shifting or sinking.
Connect the Downspouts: Attach your roof’s downspouts to the tank’s inlet using pipes or rainwater diverters. This setup directs rainwater from your roof into the tank.
Implement Filtration: Install a filtration system at the tank’s inlet to remove debris and contaminants from the collected rainwater.
Overflow Management: Ensure the tank has an overflow outlet connected to a suitable drainage area to handle excess water during heavy rains.
Secure Access Points: Install access points with secure lids for maintenance and water extraction without compromising safety or water quality.

Durability of Underground Rainwater Collection Tank Systems

The durability of underground rainwater collection tank systems is influenced by several factors. Here are the main points:

Material Quality:
- Stainless Steel, Copper, Zinc: Can last over 60 years due to corrosion resistance.
- High-Quality Plastics: Also durable, often lasting over 60 years.
Proper Installation: Ensures the tank is well-placed to handle environmental pressures.
Regular Maintenance: Increases lifespan by addressing minor issues before they become major problems.
Soil Conditions: Impact the longevity of the tank; proper assessment and preparation can mitigate negative effects.
Protective Coatings/Linings: Additional protection can extend the tank’s life.
Submersible Pumps: Sealed units that must be replaced if they fail, but regular maintenance can prevent premature failure.

How Long Can You Keep Rainwater in Underground Tanks?

The shelf life of stored rainwater in underground rainwater collection tank systems can vary, but with proper maintenance and filtration, it can be preserved for extended periods. Here are key points to consider:

Filtration: Systems include filters to remove leaves, dirt, and other debris, ensuring clean water.
Regular Maintenance: Regular checks and cleaning of the tank help maintain water quality.
Water Treatment: Use of water treatment methods, if necessary, to ensure suitability for non-potable uses.
Optimal Conditions: Under optimal conditions, stored rainwater can remain usable for several months, which is ideal for irrigation and flushing toilets.

Underground rainwater collection tanks indeed offer significant benefits. However, they come with higher installation costs and can be harder to access for maintenance. Weigh these pros and cons to decide if an underground tank is right for you.

With good planning and upkeep, these tanks can provide a reliable and sustainable water storage solution for your home.

Can You Put A Rain Water Tank Underground?