(A) Policy on open ditches. Open ditches shall be avoided wherever possible in a subdivision where pipe sizes are larger than 36 inches, the requirement of stormwater sewer pipes may be waived in favor of ditches. If an open ditch is required, the open ditch (channel) shall meet the following requirements.
(B) Channel size. (Manning's formula) Q= (1.468/n) * A * R2/3 * S1/2. | |
(C) Value of "n." | |
(1) Rock Lined Channels | 0.08 |
(2) Grassed Channels | 0.03 |
(3) Concrete or Bituminous Lining | 0.015 |
(D) Minimum side slopes (grass). | |
(1) Desired | 4:1 |
(2) Minimum | 2:1 |
(E) Minimum free board. | 1 foot |
(F) Minimum grade. | |
(1) Grass | 0.5% |
(2) Concrete | 0.35% |
(G) Channel protection. | |
(1) Seeding | 0% - 2% |
(2) Sodding | 2% - 5% |
(3) Lining | Over 5% and at all channel curves and at junctions with other channels. |
(H) Sump pumps and floor drains. Sump pumps and floor drains shall be tied into the foundation drain or the stormwater sewer system, unless said sump pump has a laundry or shower (gray water) tied to it. In this case, the sump pump must be connected to the sanitary sewer.
(I) Roof drains. Roof drains are not permitted to be discharged into the sanitary sewer system or allowed to be discharged directly into the curb and gutter adjacent to the roadway unless approved by the City Engineer. Roof drains shall be tied directly into the stormwater system. The roof drains may be sheet drained into the yard area if grade and area are sufficient and approved by the City Engineer.
(Ord. - -, passed - -03; Am. Ord. 16-2020, passed 12-7-20)