- Asset
- Modular attenuation or infiltration system
- Purpose
- Manage surface water according to the design
- Check first
- System type and inspection-channel layout
- Main limit
- Access varies between products and installations
System type and access
Modular crate systems can be built for attenuation or infiltration, depending on the drainage design. The units, wrapping, inlets, inspection channels and flow-control arrangement determine what can be inspected or cleaned. Access is not the same across all underground crate systems.
As-built drawings and manufacturer information matter here. Wavin’s AquaCell range, for example, includes product-specific inspection and maintenance features. Those features should not be assumed to exist in an unidentified installation.
Keeping sediment out of the system
Silt and debris entering the storage system can occupy storage space or obstruct parts of the drainage route. Upstream gullies, catchpits and other sediment controls are therefore part of the maintenance picture, not separate from the crate system.
Recent construction, flooding or repeated inlet restrictions may help explain how material reached the system. The stated storage capacity does not show where deposits are sitting or whether the installed access points can reach them.
Limits on inspection and cleaning
Inspection equipment and cleaning methods need to suit the access provided by the installed product and its manufacturer’s instructions. A single jetting pressure or a blanket promise to clean every internal space is not a sound specification for every crate system.
Water or sediment mobilised during cleaning also needs a controlled route. It should not be flushed into an unauthorised outfall simply to clear the storage system.
Reporting what was accessible
A completion record should state which channels or access points were inspected, what was found, what material was removed and any areas that could not be assessed. Faults involving the flow control, damaged units or the original design capacity are separate from routine sediment removal and may need further technical assessment.