Earthen channel side slopes shall be no steeper than 2:1. Flatter slopes may be required to prevent erosion and for ease of maintenance. Where channels will be lined, side slopes shall be no steeper than 1-1/2:1 with adequate provision made for weep holes. Side slopes steeper than 1-1/2:1 may be used for lined channels; provided, that the side lining and structural retaining wall are designed and constructed with provisions for live and dead load surcharge. [Ord. 12-1-97C § 13(C).]