When determining appropriate grading and sloping stabilization measures, consideration shall be given to length and steepness of slope, soil type, unsloped drainage area, groundwater conditions and proposed land use. Technical standards and specifications for measures to be taken to meet the following criteria are found in the current version of the EPA NPDES General Permit For Construction Site Storm water and Rainwater and Land Development: Ohio 's Standards for Stormwater Management, Land Development and Urban Stream Protection.
(a) Unstable Lands. Wherever the geologic stability of natural or man-made slopes may be threatened by new development, the developer shall take protective measures, including but not limited to retention structures and/or the setbacks described in Section 1154.03(b)(3), to stabilize such slopes both within and, with the approval of the appropriate landowner, outside of the development area, in order to protect the public health, safety, and welfare.
Lands identified by the City of Marietta as having a medium or high landslip/soil slippage potential shall not be graded, excavated, or filled or have loads imposed upon them unless the work is done in accordance with a stability analysis and development plan prepared and certified by a Registered Professional Engineer, as prescribed in Section 1153.05 "Plan Contents"
(b) Cut and Fill Slopes. Cut and fill slopes shall be designed, constructed, and maintained in a manner that will maximize stability and minimize erosion. Consideration shall be given to length and steepness of slope, soil type unslope drainage area, and groundwater conditions when determining appropriate drainage management and slope stabilization measures. The following standards and specifications are in addition to those stated in the current version of Rainwater and Land Development: Ohio’s Standards for Stormwater Management, Land Development and Urban Stream Protection.
(1) Rock or similar irreducible material with a maximum dimension greater than eight (8) inches, organic materials, and construction and demolition debris shall be prohibited from fills, unless such fills are intended and approved by the City as mass rock fills or disposal fills.
(2) Fills shall be compacted to a density that is appropriate for the intended use. That density shall be determined by laboratory analysis of the fill material prior to its placement. Field density shall be determined by a recognized standard procedure as approved by the City Engineer. Results of any required laboratory and field density analyses shall be filed with the City; and
(3) The horizontal distance from the top and from the toe of an existing or proposed unrestrained cut or fill slope to the nearest existing or proposed structure, property line, or paved surface shall be at least one-half (½) the vertical height of the cut or fill, unless the City Engineer shall approve a different distance as appropriate based upon local geology or character of materials. (See Section 1155.02, Figure 1.)
(4) There shall be a minimum two percent (2%) surface grade from all buildings.
(Ord. 280(22-23). Passed 6-15-23.)