Horizontal Storm Drain Piping
Capacities of horizontal storm drain piping systems.
Recommended size of horizontal storm drains below or above ground can be found in the table below. The drained area may be roofs, paved courtyards or similar.
| Drain pipe diameter | Area to be drained | ||||||
|---|---|---|---|---|---|---|---|
| Slope | |||||||
| mm | inches | 1% | 2% | 4% | |||
| m2 | ft2 | m2 | ft2 | m2 | ft2 | ||
| 80 | 3 | 75 | 820 | 110 | 1180 | 150 | 1620 |
| 100 | 4 | 175 | 1880 | 245 | 2640 | 350 | 3770 |
| 150 | 6 | 495 | 5350 | 700 | 7550 | 995 | 10700 |
| 200 | 8 | 1070 | 11500 | 1515 | 16300 | 2135 | 23000 |
The table is based on a rainfall intensity of 100 mm per hour (4 inches per hour). The anticipated rainfall intensity should always be checked with the local authorities.
