| Drainage group | Difference to the project elevation (m) | Types and number of structures | ||||||||||||||
| Total | Bridge | Culvert | Pipe outlet | Other | ||||||||||||
| Total | Error | % | Total | Error | % | Total | Error | % | Total | Error | % | Total | Error | % | ||
| D-25 | −0.10 - −0.49 | 11 | 24.5 | 11 | 29.8 | |||||||||||
| <−0.50 | 1 | 2.2 | 1 | 50 | ||||||||||||
| (−) elevation | 12 | 26.7 | 11 | 29.8 | 1 | 50 | ||||||||||
| +0.10 - +0.49 | 23 | 51.1 | 2 | 40 | 20 | 54 | 1 | 100 | ||||||||
| >+0.50 | 10 | 22.5 | 3 | 60 | 6 | 16.2 | 1 | 50 | ||||||||
| (+) elevation | 33 | 73.3 | 5 | 100 | 26 | 70.2 | 1 | 50 | 1 | 100 | ||||||
| Total | 55 | 45 | 81.8 | 5 | 5 | 100 | 47 | 37 | 73.7 | 2 | 2 | 100 | 1 | 1 | 100 | |