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Design flexibility

Enormous drainage design flexibility is possible with concrete drainage design due to a wide choice of standard product sizes and range of components. They can be used in traditional drainage design applications and as part of a sustainable drainage system as surface water sewers, foul water sewers, culverts, attenuation tanks, soakaways, pumping chambers, flow control chambers, rain water harvesting tanks and even ground source renewable energy systems. Precast concrete drainage systems can be manufactured as bespoke off-site water management solutions, including chambers with in-built weir walls and hydraulic devices such as hydrodynamic silt separators and vortex flow regulators.

The use of concrete products in surface water and foul water drainage design is beneficial as they can often be modified on site to accommodate a wide range of ad-hoc variations whilst maintaining structural integrity.


Standard pipe sizes range from DN225 to DN2400 and manholes DN900 to DN3000 are readily available. One–off solutions can also be offered for larger sizes.

In some situations, it may also be possible to design systems using higher strength pipes to meet particularly onerous design loads.

For specific manufacturer product information see our members page.

Rigid concrete pipes with flexible joints provide additional advantages in terms of structural and hydraulic design.

As the pipe itself forms part of the pipeline structure, it is often possible to design systems with a number of alternative bedding designs. This can lead to substantial installation cost, time and embodied carbon savings in addition to reduced environmental impact when compared with systems requiring a full granular surround.

The fact that concrete pipes do not deform or lose their shape also means that hydraulic performance is preserved. Deformation at the joint can lead to compromised performance of the seal and pipes that change their shape over time, both in terms of the cross-section and longitudinally, can also reduce the hydraulic efficiency of drainage systems.