§ 25-98. Storm drainage criteria.

(a)

Storm drainage for residential areas shall be designed for a ten-year frequency rainfall, shopping centers and industrial developments for a ten-year frequency, and downtown and central business district for a twenty-five-year frequency rainfall.

(b)

The drainage system shall be designed and constructed to handle rainfall runoff that originates in or traverses the subdivision.

(c)

Street crowns shall not be flattened, or warped, from one (1) side of the street to the other for the purpose of causing water to flow from one (1) side of the street to the other side, unless specifically approved by the city engineer.

(d)

Water shall be picked up in all streets at least every six hundred (600) feet by means of catchbasins, drainage pipes or curb and gutter. Unpaved drainage swales or ditches shall be allowed along rear lot lines or in common space where it can be demonstrated to the planning commission that surface drainage is adequately accommodated. Where catchbasins are located, drainage shall be underground along front or side yard easements or street rights-of-way.

(e)

Individual drainage of each lot shall be the responsibility of the individual home builder or lot purchaser. However, it is the responsibility of the developer to provide adequate drainage easements and structures such that proper drainage can be effectuated through use of "Turtle Back" lot contours or swales.

(f)

No open drainage channels shall be constructed within the area dedicated as public streets and alleys.

(g)

As a general policy, a developer shall be required to improve major drainage channels on a prorated basis, based on the percentage of total drainage area contributed by a given development. The design characteristics of each development and its provision for drainage shall also be considered when calculating major drainage improvements.

(h)

Whenever drainage ditches are used, such ditches may require concrete or gunite lining, designed to retain their original design characteristics, and designed so they can at all times be kept clean and easily maintained.

(Subdivision Regulations, § VIII(K))