A. The provisions of this section shall apply to any building site where the topographic slope of said building site exceeds fifteen percent (15%) grade.
B. Cut and fill slopes shall comply with the following development standards:
1. Fill areas shall be prepared by removing organic material, such as vegetation and rubbish, and any other material which is determined by the soils engineer to be detrimental to proper compaction or otherwise not conducive to stability; no rock or similar irreducible material with a maximum dimension greater than eight inches (8") shall be used as fill material in fills that are intended to provide structural strength.
2. Fills shall be compacted to at least ninety five percent (95%) of maximum density, as determined by AASHO T99 and ASTM D698.
3. Cut slopes shall be no steeper than two (2) horizontal to one vertical; subsurface drainage shall be provided as necessary for stability.
4. Fill slopes shall be no steeper than two (2) horizontal to one vertical; fill slopes shall not be located on natural slopes two to one (2:1) or steeper, or where fill slope toes out within twelve feet (12') horizontally of the top of an existing or planned cut slope.
5. Tops and toes of cut and fill slopes shall be set back from property boundaries a distance of three feet (3') plus one-fifth (1/5) of the height of the cut or fill, but need not exceed a horizontal distance of ten feet (10'); tops and toes of cut and fill slopes shall be set back from structures a distance of six feet (6') plus one-fifth (1/5) the height of the cut or fill, but need not exceed ten feet (10').
6. The maximum horizontal distance of disturbed soil surface shall not exceed seventy five feet (75').
7. All cut and fill slopes shall be revegetated and/or rehabilitated with retaining walls to eliminate unsightly hillside scarring and erosion. In those instances when it is necessary to disturb naturally vegetated slopes during construction of dwellings and other associated improvements, the disturbed slope areas shall be repaired and revegetated. Temporary or permanent watering systems shall be installed and maintained during revegetation to ensure adequate growth on revegetated existing or new cut and fill slope areas. Revegetation shall consist of drought tolerant ground cover plantings, dry land grasses, shrubs, and trees combined with rock groupings, retaining walls or other similar designs or methods to prevent soil erosion and unsightly views. Plants and materials used in the revegetation shall not be of a type or variety to cause an environmental threat or concern to the local or forest environment and shall not include any plants listed as noxious weeds by Custer County.
C. Revegetation as defined in subsection B for all cut and fill slopes shall be completed no later than twelve (12) months from the expiration date of the building permit or within twelve (12) months of building completion, whichever is earlier.
D. Retaining walls are limited to eight feet (8') in height above finished grade of retaining wall unless otherwise approved by the city council. For areas or slopes exceeding eight feet (8') in height above the finished grade, or as required by engineering or other circumstances, stair stepped or offset retaining walls shall be constructed. Unless approved otherwise by the city council, the horizontal distance between the stepped or offset wall shall not be less than one-half (1/2) the retaining wall height. Retaining walls shall be constructed of durable or permanent materials, which are attractive earth tone or natural material, or otherwise screened. Types of approved retaining wall materials include keystone block, large rock, natural rustic wood, railroad ties or other similar natural material. A "retaining wall" shall be defined as a structure built of approved materials, whose purpose shall be to stabilize existing or manufactured slopes for both the prevention of erosion and the creation of a building site. A retaining wall, which is in an integral part of a building's structural design, and is attached to the building shall be considered as part of that building's "viewable facade", with the provision that its total length does not exceed twenty percent (20%) of the length of the main building, and therefore not subject to the eight foot (8') height limitation.
E. No building shall have a viewable facade that exceeds twenty eight feet (28') in height, unless a daylight basement is approved by the City Council, in which case the viewable facade as viewed from no more than three (3) sides shall not exceed thirty eight feet (38') in height. A "daylight basement" shall exist when at least one side of the basement level is totally or partially excavated or backfilled into a hillside, and at least two (2) other sides significantly excavated or backfilled into a hillside. At least one side must have a viewable facade of no more than twenty-eight feet (28') in height. The "viewable facade" of a structure shall be defined as the total visible portion of that structure from any particular side, from lowest point to rooftop.
F. Construction of dwellings and associated improvements should take into consideration the need for erosion control facilities and techniques during and after construction. Silt fences, straw bales, berms and ditches are examples of temporary techniques to control erosion. Under no circumstances shall uncontrolled erosion be allowed to deposit eroded materials on any adjacent lot, roadway, stream or wetland area. Existing or new cut and fill slopes should be protected from erosion potential. Permanent erosion control facilities should be incorporated in the design of the dwelling, lot grading, landscaping and other improvements. (Ord. 229, 7-31-2025: Ord. 213, 7-8-2021: Ord. 152, 11-7-2001)