Stormwater Module Tank

Stormwater Module Tank

Stormwater Module Tank System is a subsurface water infiltration storage tank for stormwater control and management system, and thus, it is also known as the Modular Rainwater Storage / Harvesting System, Underground Tank System and Sub-soil Drainage System in the market. It is efficient, cost effective and ecologically sustainable. The main function of Modular Tank is to allow on-site natural water infiltration and this prevent surface run-off. This Underground Tank System is best applied for flat ground area for rainwater harvesting and stormwater management.
Stormwater Module Tank System has unique advantages, such as: high compressive strength allows to be used under trafficable areas, Interlock system that maximize stability and installation, less costly than concrete and metal storage systems, low storage and transportation cost, and it caters for all volume requirements. In addition, this Underground Tank System, offers advantages in assembly of panels and installation of units, no surface water storage hazards, and achieving LEED SS, WE and MR credits and BCA Green Mark points. Overall, Modular Rainwater Storage System is effective and versatile for water storage.


  • High compressive strength allows use under trafficable areas
  • Interlocks vertically and horizontally for maximum stability
  • Less costly than concrete and metal storage systems
  • Low storage and transportation cost
  • Caters for all volume requirements
  • Easy assembly of panels and insallation of units
  • No surface water storage hazards
  • Contributes to achieving LEED SS, WE and MR credits and BCA Green Mark points


Overall Footprint :

Arches require a much larger footprint than box systems, which is tied to the amount of excavation and backfill material the contractor will have to haul and place. On average, a Module system can reduce the stone backfill by 40-60%. Depending on the region, this can translate to huge cost savings. For example, most installations require hundreds and thousands of tons of stone, which is typically anywhere from $40-50 per ton.
Box structures can also be flexibly designed to meet specific site requirements and layouts. The Module is easily designed around existing structures and within tight constraints, offered in a range of heights to vary storage capacity, and is stackable to reduce installation footprint.

Capacity :

Since box structures feature a higher void space than arches, they rely less on the stone backfill for storage capacity. For this reason, box systems with less height can accomplish the same capacity as a deeper arch. This means the excavation depth can be reduced, less rocks will need to be removed, and the box units can be placed above the water table.

Buoyancy :

All underground storage systems are susceptible to buoyancy issues depending on the submergence depth. However, arch systems are more at risk of reduced capacity or damage caused by buoyancy because there is no restraint under the arch itself. This means the liner and stone leveling bed can rise into the void space and reduce storage capacity when surrounded by groundwater.

Ease of Installation :

Though box structures require some level of field assembly, they can be moved and placed by a single individual. In fact, StormTank Modules can be assembled in less than two minutes and are easy to place and connect. On the other hand, arch products typically require multiple people to move and place the product, technically doubling the time to install one unit, with some taller sizes even requiring a third person. Additionally, because each arch system is made up of multiple product rows, the system requires a manifold that box structures do not.

Strength :

This point is commonly misunderstood and can vary as much by a manufacturer as by product type. If we use the StormTank Module as an example, it has been designed and tested to support the load above it better than most arch products. However, the only true way to determine a strength comparison is to conduct full-scale installation testing, utilizing tools like strain and displacement gauges. (Do not be fooled by steel press tests that don’t gather meaningful data or driving uncalibrated trucks over the system!)