| Layer | Parameter | Unit | Green roof | Rain barrel | Permeable pavement |
|---|---|---|---|---|---|
| Surface | Bern height | mm | 30 | - | 25 |
| Vegetation volume fraction | - | 0.7 | - | 0 | |
| Surface roughness | - | 0.4 | - | 0.12 | |
| Surface slope | % | 0.01 | - | 1 | |
| Swale side slope | - | - | - | - | |
| Pavement | Thickness | mm | - | - | 60 |
| Void ratio (Voids / Solids) | - | - | - | 0.13 | |
| Permeability | mm/hr | - | - | 200 | |
| Soil | Thickness | mm | 300 | - | 150 |
| Porosity | - | 0.5 | - | 0.5 | |
| Field capacity | - | 0.2 | - | 0.1 | |
| Wilting point | - | 0.1 | - | 0.024 | |
| Conductivity | mm/hr | 35 | - | 100 | |
| Conductivity slope | - | 7 | - | ||
| Suction head | mm | 3.5 | - | - | |
| Drainage mat | Thickness | mm | 100 | - | - |
| Void fraction | - | 0.43 | - | - | |
| Roughness | - | 0.03 | - | - | |
| Storage | Thickness | mm | - | 1000 | 250 |
| Void ratio | - | - | - | 0.43 | |
| Seepage rate | mm/hr | - | - | 600 | |
| Drain | Flow coefficient | - | - | 0 | 0.69 |
| Flow exponent | - | - | 0.5 | 0.5 | |
| Offset | mm | - | 6 | 6 | |
| Drain delay | hr | - | 72 | - |