Stormwater Pits (CPO)

The Rocla CPO® Stormwater Pit system is designed specifically for stormwater applications. It provides a simple, high quality and cost-effective alternative to traditional pit installations.  

The system comprises of a precast base, chamber sections and a variety of covers, grates and lintels.  Standard CPO diameters range from 600mm to 1200mm and come in a range of component depths, with or without steps.

Chambers are manufactured from high strength, low-permeability concrete in accordance with AS4058 for steel-reinforced concrete pipe.

Circular pits mean that pipes enter and exit from the centre of the pit. Unlike square pits, pipes don’t have to penetrate corners. CPO pits also offer better hydraulics and reduced headloss compared to square pits.

Penetrations for CPO pits are easily punched out on site, ensuring maximum flexibility and allowing for late minute design changes. Unlike square knock out pits, the full wall thickness is maintained for the entire pit.


  • Stormwater drainage pits
  • RTA drainage pit applications
  • Diversion pits