Wetland Trail Design and Construction: 2007 Edition
Appendix C—Comparison of Round and Rectangular Culverts
These tables show the open-end area of round culvert pipe and the open-end area of rectangular timber culverts.
| Diameter (inches) | 8 | 10 | 12 | 15 | 18 | 24 | 30 | 36 |
|---|---|---|---|---|---|---|---|---|
| End area (sq. ft) | 0.4 | 0.6 | 0.8 | 1.2 | 1.8 | 3.1 | 5.0 | 7.1 |
| Clear width (inches) | ||||||||
|---|---|---|---|---|---|---|---|---|
| 20 | 24 | 30 | 36 | 48 | 60 | 72 | 84 | |
| Height (inches) | End area (sq. ft) | |||||||
| 5 | 0.7 | 0.8 | 1.1 | 1.3 | 1.7 | 2.1 | 2.5 | 2.9 |
| 11 | 1.4 | 1.8 | 2.3 | 2.8 | 3.7 | 4.5 | 5.5 | 6.4 |
| 17 | 2.1 | 2.9 | 3.6 | 4.3 | 5.0 | 7.1 | 8.5 | 9.9 |
| 23 | 2.9 | 3.8 | 4.8 | 5.8 | 7.7 | 9.6 | 11.5 | 13.4 |
