(A) Manhole spacing. The maximum spacing between storm manholes shall be 500 feet.
(B) Minimum pipe size.
(1) The minimum diameter of any storm drain pipe shall be 12 inches, except that a maximum length of 60 lineal feet of eight-inch diameter pipe may be used between inlets and manholes.
(2) The minimum size of any storm drain culvert is 12 inches.
(C) Storm drain manhole ring and cover.
(1) The storm drain manhole ring and cover shall be East Jordan Iron Works Model 3 772Z 1 or an approved equal.
(2) The cover shall be marked “storm.”
(D) Curbs and gutters or swales.
(1) Streets and roads shall be designed to ensure proper drainage and curbs and gutters or swales shall be required in all subdivisions.
(2) Curbs and gutters of adjoining properties shall be extended to match any new curb and gutter. Gutter, ditch and swale flow line grades shall be greater than 0.5%.
(E) Culverts and drainage facilities. Culverts of adequate size shall be provided and installed by the developer where drainage channels intersect any street right-of-way or easement. All culverts shall extend at least the width of the base of the fill.
(1) The amount of backfill to be placed over the culvert and a culvert’s capacity shall be determined by a licensed professional engineer.
(2) This shall include arrangements for driveway culverts. Culverts larger than 24 inches shall have flared ends.
(F) Drain inlet frame and grate. The curb inlet frame and grate shall be Olympic SM 49, East Jordan Iron Works combination of product numbers 7222Ml or 7222M3 (Herringbone grate) or an approved equal.
(G) “Beehive” area drain frame and grate. The beehive area drain frame and grate shall be Neenah Foundry Model R-2560-D6 “beehive grate with frame,” East Jordan Iron Works 1205-2 or an approved equal.
(H) “Drive over” area drain frame and grate. The drive over area drain frame and grate shall be Neenah Foundry Model R-2556-A Type C frame with Type G grate, East Jordan Iron Works Model 1848-G or an approved equal.
(I) Sump requirements for catch basins and manholes. A 18-inch sump is required for catch basins and drain inlets. A 24-inch sump is required for storm drain manholes.
(Prior Code, § 11.05.040.050) (Ord. 2019-9, passed 9-3-2019; Ord. 2021-15, passed 12-20-2021)