Rainwater tanks are an integral part of any Rain Harvesting system.  

When selecting a rainwater tank or tanks for your property, you can choose between two broad categories: aboveground or underground.  

As their name suggests, aboveground tanks are installed aboveground, either next to your home, underneath it (for houses on stilts) or further away on your property. Underground tanks are installed completely underground or partially belowground. Like aboveground tanks, they can be installed next to your home or further away.  

Your choice of aboveground vs underground tanks will depend on several factors.  

Below, we explore the key differences between these options and the factors that may determine your choice one way or the other.  

Aboveground rainwater tanks 

A popular option, aboveground tanks can be made from concretemetal (including steel), polyethylene (plastic) or fibreglass. “Bladders” are another form of water storage unit that can be installed aboveground in relatively tight spaces.  

Aboveground tanks are fairly quick and easy to install, especially as you don’t have to excavate a space for them first. This makes them a comparatively low cost option for rainwater storage. Aboveground tanks are also easy to inspect for possible damage.

Underground rainwater tanks 

Underground tanks are most commonly made from concrete or reinforced polyethylene (plastic). They’re more expensive to install than their aboveground counterparts as they require excavation and the materials they’re made from need to be reinforced.  

The greatest benefit of underground rainwater tanks is their space saving nature. They can be installed in smaller properties where the size of your property would otherwise prohibit the use of a tank. Underground tanks are often installed underneath driveways and are a popular choice for new home developments. Some people also prefer underground tanks because they don’t affect your property’s aesthetics.

The right tank for you 

Your choice of aboveground vs underground rainwater tank will be largely determined by your budget, available space and preferences.  

Whatever you decide, be sure to complement your chosen tank/s with the appropriate equipment and processes to ensure your Rain Harvesting system gives you cleaner rainwater and lots of it.  

Click here to learn more about designing the right Rain Harvesting system for your property and needs