Rules for building cuts and fills on your property

(a) The requirements of this section may be waived by the director of public works after the permittee submits an engineer’s soils report substantiating data regarding the stability of the cut or fill slopes without complying with any of the requirements therein. (1) Height. Where a cut or fill is greater than fifteen feet in height, terraces or benches shall be constructed at vertical intervals of fifteen feet except that where only one bench is required, it shall be at the midpoint. The minimum width of such terraces or benches shall be eight feet or as determined by the director of public works, based upon the type of material encountered and shall have suitable drainage provisions to control erosion on the slope face. EROSION AND SEDIMENTATION CONTROL § 10-18 (2) Cut Slopes. Under the following soil conditions, no cut may be steeper in slope than the ratio of its horizontal to its vertical distance as shown below: ½ horizontal to 1 vertical in unweathered rock; 1½ horizontal to 1 vertical in decomposed rocks or rock and soil mixture; 2 horizontal to 1 vertical in low plasticity soils; 3 horizontal to 1 vertical in high plasticity soils for cuts up to five feet in vertical depths. Slopes for cuts exceeding this depth shall be as recommended in the engineer’s soils report. (3) Fill Slopes. Under the following soil conditions, no fill may be steeper in slope than the ratio of its horizontal to its vertical distance as shown below: 1½ horizontal to 1 vertical in rock and soil mixture; 2 horizontal to 1 vertical in low plasticity soils; 3 horizontal to 1 vertical in high plasticity soils for fills up to five feet in vertical height. Slopes for fills exceeding this height shall be as recommended in the engineer’s soils report.