A. Applicability: Because of the dramatic visual impact of cuts, fills and retaining walls in a desert environment such as the city, and the public safety factors that may arise with significant cuts and fills in unsuitable soils, design plans for cuts, fills and retaining walls shall conform to the following criteria and other applicable sections of this title, and the city design guidelines:
1. No cuts or fills will be allowed on slopes with grades exceeding thirty percent (30%).
2. Unretained cuts that exceed two to one (2:1) slope shall not exceed eight feet (8') in height.
3. Unretained fills may not exceed twelve feet (12') in height pursuant to subsection B of this section.
4. No single retaining wall or retaining system may exceed twelve feet (12') in height and/or forty feet (40') in length; retaining systems less than twelve feet (12') may exceed forty feet (40').
5. Up to three (3) terraced cuts may be created under a terraced cuts retaining system, so long as each wall is separated by a minimum four foot (4') setback (measured from face to face) for visual relief and revegetation. The total maximum height for cuts retained under a terraced retaining system shall not exceed eighteen feet (18').
6. All fills over four feet (4') shall be engineered and approved by a licensed state engineer.
B. Measuring Cut/Fill Heights: Cuts and/or fills shall be measured vertically, from the natural grade at the lowest point of disturbance to natural grade at the highest point of disturbance.
C. Maximum Slope Grades: Unretained cut and fill slopes shall be no steeper than two feet horizontal to one foot vertical (2:1), except that cuts in bedrock materials, the stability of which is verified by a geologist and/or soils engineer with demonstrated expertise, may be steeper as approved by the city engineer.
D. Retaining Walls: All retaining walls and/or approved retaining systems shall be constructed of decorative materials (i.e., textured surfaces, colored or tinted materials) and should be designed to blend into and enhance the natural desert environment and must be approved by the building department before grading or excavation permits shall be granted.
E. Engineering/Geologic Analysis: An engineering/geologic report in compliance with subsection 10-6-2F of this title, shall be prepared by a registered geologist or engineer at the schematic plan stage of the subdivision ordinance to demonstrate that the hillside above any proposed cut will remain stable after the proposed cut/fill and retaining system, if any, has been completed.
F. Revegetation:
1. All unretained cut and fill slopes must be naturalized and revegetated within one year after the start of construction.
2. Unretained cuts and fills should be naturalized by rounding edges, placing boulders in natural fashion and planting native plants, including trees, brush and ground cover, to match surrounding areas. A landscape/revegetation plan shall be submitted to the planning commission for review and approval with the cut/fill design plans.
3. All retaining systems shall incorporate planter spaces and shall require native revegetation. (Ord. 2012.04, 1-18-2012)