Attenuation Volume to Crate Count Estimator

Once the drainage strategy has fixed the attenuation volume, the next question is how much ground the crate field will actually take. This converts a storage duty into module count, plan area and excavation depth — the three numbers a groundworks package is priced on.

1. Attenuation storage volume required (m³)

2. Module depth

H400 — 400 mm deep, 190 L per unit H500 — 500 mm deep, 237.5 L per unit

3. How many layers can the build-up stack?

1 layer 2 layers 3 layers 4 layers

Enter a storage volume between 1 and 20,000 m³.

Module
Storage delivered
Plan area of the crate field
Crate stack depth
Land equivalent, if held as an open basin instead

Get a storage-volume estimate and kit take-off

Module count is derived from the nominal unit volumes above at a 95% void ratio, on a 1.0 m × 0.5 m module footprint. It is an indicative take-off for early feasibility, not a drainage design: silt-loss allowance to CIRIA C737, geotextile and geomembrane wrap, flow-control chamber, inspection access and excavation batter are excluded. Containerised loading quantities depend on module depth and packing and are quoted per order.