Sizing a modular rainwater tank begins with local rainfall, contributing catchment area and the project objective. A reuse tank is assessed against supply and demand, while an attenuation tank is checked against inflow, permitted discharge and design-storm criteria.

System role and suitable projects
This page focuses on rainfall-based sizing. The 0.125 m³ PP module is the building unit, but the effective tank volume must also allow for system geometry, access, sediment control and any unusable or reserved volume.
- Early-stage rainwater storage estimates
- Roof runoff volume calculations
- Attenuation tanks with a controlled outlet
- Reuse systems balancing rainfall supply and demand

Module specifications
The following values are the legacy product specifications for this module. Structural capacity, cover depth, traffic loading and applicable test requirements must be checked for the actual project design.
| Type | Rainwater Collecting Modular |
| Place of Origin | Fujian China(Mainland) |
| Brand Name | LEIYUAN |
| Material: | PP |
| Color: | Black |
| Dimension | 680 L*410 W*450Hmm |
| Total Volume: | 0.125m3 |
| Tank per m3 | 8 |
| Weight: | 8kg/module |
| Working Temperature: | From -30℃ to +120 ℃ |
| Pressure Strength: | 25tons/sqm |
| HS Code: | 3925900 |
| Certificate: | ISO9001:2008 |
How the modular tank works
Designers calculate runoff from rainfall depth, catchment area and runoff coefficient, then compare inflow with reuse demand or allowed discharge. The resulting effective storage is converted into a practical module layout and checked against site constraints.

Installation planning
- Confirm runoff volume, design storm, inflow and discharge requirements.
- Check excavation, groundwater, soil bearing conditions and required cover depth.
- Prepare a level base and assemble modules according to the approved layout.
- Wrap the structure with the specified geotextile and/or waterproof membrane.
- Connect inlet, outlet, ventilation, inspection and overflow components.
- Backfill in controlled layers and commission the system before operation.


Packing and project support
| Detail: | Size | Packing |
| 680x410mm | 8pcs/bundle | |
| 450x410mm | 10pcs/bundle | |
| Shipping: | 90 Cubic Meter for 1X20′ GP(By bundle) |
Module quantities and container loading should be confirmed from the final tank geometry and current packing plan. Leiyuan can review project volume, module layout and shipping requirements for professional buyers.


Information required for a quotation
Send the project location, required storage volume, application, installation depth, surface load, groundwater level, drawings and delivery destination. This allows the module and system build-up to be checked before quotation.