Amendments to DWA-A118 (2006) and EN 752 (2008) with regard to precipitation frequency, reflecting future sewerage overloads, according to Merkblatt Nr. 4.3/3 (2009).
| No. . | Land development . | Precipitation frequency (once in N years) . | |
|---|---|---|---|
| For verification of surcharge . | For verification of flooding . | ||
| 1 | Rural areas | 3 instead of 2 | 50 instead of 10 |
| 2 | Residential areas | 5 instead of 3 | 100 instead of 20 |
| 3 | City centers, service, and industry areas | 10 instead of 5 | 100 instead of 30 |
| No. . | Land development . | Precipitation frequency (once in N years) . | |
|---|---|---|---|
| For verification of surcharge . | For verification of flooding . | ||
| 1 | Rural areas | 3 instead of 2 | 50 instead of 10 |
| 2 | Residential areas | 5 instead of 3 | 100 instead of 20 |
| 3 | City centers, service, and industry areas | 10 instead of 5 | 100 instead of 30 |