Packet: Tiffin City Council Work Session (09/15/2026)

CHAPTER 158 SUDAS displacement, abrasion, or shock. Special provisions shall also be made for installation of energy dissipation structures downstream of any location with pipe flow velocities greater than 15 feet per second.” D. 2D-1 D. 7. a. Add the following sub-paragraphs. “1. The maximum slope for storm sewer outlet lines shall be 10 percent. 2. If reinforced concrete pipe is utilized for outlet lines having a slope greater than or equal to eight percent, all joints must be tied together. The flared end section and the last two pipe joints shall be tied together in all instances regardless of pipe slope.” E. 2D-1 D. 10. Add the following: “10. Permitted Flows: a. No sanitary sewers, sanitary sewer services, or septic tanks shall be discharged into storm sewers. b. No flows from commercial car washes shall be discharged into storm sewers. c. Sump pump discharge of ground and surface water is permitted. d. Only groundwater is permitted in sump pump discharge tiles less than 12-inches in diameter. No surface water or roof drains from private residences are permitted in these systems. Roof drains from commercial developments are permitted.” F. 2D-1 D. 11. Add the Following: “11. Outlets: All pipe outlets must extend to an existing, established drainage channel. If there are no existing channels within the property being developed, the developer shall convey the stormwater through an underground piping system to the nearest established drainage channel.” G. 2D-1 D. 12. Add the following: “12. Subsurface Drainage: a. In predominantly wet areas, area containing hydric soils, and other such areas designated by the City Engineer, a subsurface drainage system shall be provided to receive discharge from sump pumps. b. A two-inch service connection manufacture specifically for the pipe being used and approved by the City Engineer shall be provided for each lot abutting the subsurface drainage system. c. The end of all sump pump services shall be marked with a metal post or number four rebar at least 24 - inches in CODE OF ORDINANCES, TIFFIN, IOWA - 1359 -