§ 21-60. Open channels.

(a)

Open channels may be used to convey storm runoff where sufficient right-of-way is available to contain the improved cross section along with the additional width necessary for maintenance purposes.

(b)

For safety purposes, open channels should be fenced or graded to reduce potential injury to the public.

(c)

Minimum bend radius shall be twenty-five (25) feet or ten (10) times the bottom width, whichever is greater.

(d)

Open channels shall have a trapezoidal or rectangular cross section with a flat bottom. Natural open channels shall have a maximum side slope of 2:1. Paved channels shall have side slopes varying from a minimum 2:1 to vertical.

(e)

Connections at the junction of two (2) or more open channels shall be smooth with no difference in vertical channel profile unless substantiated by engineering analysis.

(f)

Drainage pipe, box culverts or storm sewers entering an open channel will not be permitted to project into the normal channel section. Nor will they be permitted to enter an open channel at an angle which would direct flow from the culvert or storm sewer upstream in the channel unless substantiated by engineering analysis.

(g)

As minimum protection to reduce erosion, all natural open channel slopes shall be seeded or sodded as soon after finish grading as possible.