Aquacomb Underground Watertank

I've had a lot of interest from friends, family and fellow builders about our underground watertank system - so thought I would dedicate a post to it!

Background: 

Our block of land is considerable small (412m2) and as part of our BASIX requirements meant we had to have a 3,000L watertank installed. Eden Brae supply a 3,000L round above ground watertank as part of the package, however we weren't too pleased about losing valuable yard space (FYI - A typical 3,000L above ground tank has a footprint of about ~1.6m x ~1.6m).

We then looked at upgrading to a slimline watertank so that we could position it around the side of the home along the fence line, however this option was a no-go because of the minimum setback requirements. 

Our last option was to investigate an underground watertank. Which by the way, was an option we pushed for verses being offered to us an alternate solution from Eden Brae - go figure!

The Solution:

The underground watertank system recommended by Eden Brae was the Aquacomb. The Aquacomb water system is designed and manufactured by an Australian company called RemTech (parent company VLP). The Aquacomb is quite an innovative and modular product that can go just about anywhere - within retaining walls, under houses, pools, garages, driveways and decks. Ours has been set within the concrete slab, and acts as a waffle pod (replacing the styrofoam pods). Our Aquacomb pods run in a straight line down the side of the house (pictures below for reference).

I guess the biggest question we get asked is "what happens if it leaks?". Good question right!

...The water pods have been specifically engineered for underground use, and the materials all comply with relevant Australian Standards and carry a 20 year guarantee (which speaks for itself!). On top of this, we're also covered under Eden Brae's building warranty for the next 6-7 years. But if it became a huge problem we could easily disconnect the tank and drain the water, so all-in-all we are not hugely concerned as it's not like we are solely relying on the tankwater.

Maintenance: 

Something else to consider is the maintenance for the Aquacomb, they recommend -

“In order to maintain the system, we incorporate access ports to allow high pressure water cleaning and draining. We also recommend leaf filters to reduce the amount of solids entering the Aquacomb system from the roof and the use of a ‘first-flush’ device to divert the initial dirty water.”

Costs:

• Aquacomb 3,000L underground tank (in lieu of standard) costed us $3,100 inc GST.
• Classic slimline 3,000L aboveground tank (in lieu of standard) costs $1,328 inc GST.

For additional research, here are some website links you might be interested in: 

• Visit the RemTech website here 
• Download the Aquacomb brochure here
• Watch Grand Designs YouTube video here: 

Links available on the HOG website:

1. Water Storage Systems
2. A smart water storage solution for your home
3. Out of sight and peace of mind

Image References:

3,000L Round Rainwater Tank

3,000L Slimline Rainwater Tank

3,000L Aquacomb Underground Rainwater Tank
Example 1 

3,000L Aquacomb Underground Rainwater Tank
Example 2 - our block

3,000L Aquacomb Underground Rainwater Tank
Example 2 - our block - close up

Did you know?

• Household water consumption is approximately 150 litres per person per day
• The average household usage for 4 people is 3,000 litres per week
• Mandatory water storage for new houses varies between 1,000L and 5,000L 
• It takes 15 minutes for 10mm of rain falling on a 240m2 roof to fill a 5,000L tank