.010 Slope Standards Generally. No excavation shall be made with a cut slope steeper than one and one-half horizontal to one vertical and slopes in excess of twenty-five feet in height that are not contour graded shall not be made with a slope steeper than two horizontal to one vertical unless the licensed Engineering Geologist or Soil Engineer in the approved report recommends that a steeper slope would be safer and more stable. Use of contour grading is required in accordance with Council Policy No. 211 and Standards approved by the City Council. Cut slopes in excess of two hundred feet in length shall be contour graded and shall have a variety of slope ratios.
The Soil Engineer or Engineering Geologist shall furnish a written opinion certifying that he has investigated the site and that the two (horizontal) to one (vertical) slope is adequate and will not endanger any public or private property or result in the deposit of debris on any public way or cause any public way to be endangered due to loss of supporting foundation as a result of slope instability.
All lots shall be graded to drain to public or private streets unless prior approval has been received from the City Engineer.
.020 Cut Faces. The City Engineer shall require additional engineering information from the licensed Engineering Geologist or Soil Engineer if, in his opinion, existing conditions make a flatter slope than one and one-half horizontal to one vertical necessary for stability and safety.
The area of cut slope shall be confined within one lot or parcel and the top of cut slopes shall be located as shown in Table 17-A, Setbacks. All exposed cut slopes shall be protected upon completion with planting as set forth in Chapter 17.06, Section 17.06.130.
.030 Terracing. Cut slopes exceeding thirty feet in vertical height shall be terraced at approximately mid-height or at maximum intervals of thirty feet. Terraces shall be at least six feet wide except that a minimum eighteen foot wide terrace shall be required at least each sixty foot interval for the height of the cut slope. Terraces shall be paved not less than six feet wide with a minimum longitudinal grade of five percent with minimum three-inch thick reinforced concrete or air-blown mortar in medium or dark earthen tones (black, tan, sienna, umber, ocher, or green) and shall carry water to a safe disposal area as approved by the City Engineer. (Refer to Table No. 17-A, Setbacks as revised on May 9, 1991).
.040 Applicability of Section. This section applies to all hillside area excavations in the City regardless of whether or not a grading plan is required by this chapter. (Ord. 3411 § 2 (part); April 1, 1975; Ord. 5242 § 1; July 16, 1991.)