A soakaway crate is a modular underground plastic structure designed to receive surface water and allow it to infiltrate slowly into the surrounding subsoil. The system replaces traditional rubble-filled soakaway pits with a high-void modular alternative that occupies less excavation volume. UK installations follow BRE Digest 365 and Building Regulations Part H3, with system sizing determined by infiltration rate testing and expected rainfall. The crates are normally wrapped in non-woven geotextile to prevent fines migration from the surrounding soil into the void. In Greater London, soakaway crates are well suited to gravel and sand subsoils but generally unsuitable in heavy clay, where attenuation with controlled discharge is preferred. Inlet catchpits or silt traps are normally specified upstream to extend the service life of the soakaway by intercepting debris before it enters the storage void.
Soakaway crate
Modular plastic crate system enabling surface water to infiltrate into surrounding ground.
