The hillside development standards are intended to illustrate and amplify the appropriate development concepts for hillside areas. The standards are intended to encourage flexibility and creativity to design projects which exceed the standards in order to respect the natural character of each hillside. The following are minimum standards and shall apply to hillside or hillside area as defined in Section 9.15.020.
(a) Hillside Slope Categories. The following descriptions serve as general standards for hillside slope categories to ensure that development will compliment the overall character of the landform.
DEVELOPMENT STANDARDS
% Natural Slope Category | Standards |
Up to 25% | This is not considered a hillside condition and is not subject to this Chapter. |
25% up to 50% | This is a hillside condition and is subject to this Chapter. Development within this slope category shall minimize impacts to grading, vegetation removal, safety and environmental and aesthetic impacts. Impact of access and roadways shall be minimized by following natural contours or using grade separations. Structures shall blend with the natural landform through their shape, material, and color. Special hillside design techniques are required, which may include the use of larger lots, variable setbacks, and variable building structural techniques and clustering. Padded building sites may be considered in some instances. Where this occurs, the City may consider padded building sites adjacent to special features when it is found that grading of padded building sites will create a better relationship between the special feature(s) and the building sites. |
35% up to 50% | In addition to the requirements of the above slope category, projects with an average slope in excess of 35% may not exceed 50% of the maximum allowable density as identified within the General Plan. |
50% and over | This is an excessive slope condition and development is prohibited. |
(b) Site Design.
(1) Grading shall not take place on natural slopes that exceed 50%.
(2) Driveway grades above 14% may only be considered when driveways are aligned with the natural contours of the land, are necessary to achieve effective site design, and safety considerations are met to the satisfaction of the Building Official, City Engineer, and the Fire Department. Proper design considerations shall be employed, including the use of vertical curves. On driveways that may be approved with a slope greater than 14%, a coarse, all-weather paving material, or grooves for traction, shall be incorporated into the construction.
(3) Roadways shall conform to the natural landform. Significant alterations to the physical and visual character of a hillside shall be avoided by eliminating large notches in ridgelines and wide straight alignments. Modified or reduced width road sections and split sections shall be considered in the layout of hillside streets to reduce grading and cuts in topography while allowing access for fire trucks and other emergency vehicles.
(4) Slopes in excess of 2:1 shall not be allowed and slopes shall not exceed 30 feet in height between terraces or benches.
(5) Fill slopes shall not be placed perpendicular across a canyon. Straight line cut-off fill slopes shall not be made to appear like a dam. The terminus of the fill shall, instead, be concave in shape to restore the canyon appearance. This concave configuration shall be in combination with the use of substantially flatter slope ratios (4:1, 3.5:1, 3:1) at or near the center of this indentation. Symmetrical or unsymmetrical concave configurations shall be used depending upon the adjoining or underlying topographic characteristics.
(6) Grading shall be phased so that prompt renegotiation or construction will control erosion. Where possible, only those areas that will be built on, resurfaced, or landscaped within the next 120 days shall be disturbed. Top soil shall be stockpiled during rough grading and used on pads or revegetated habitat areas, upon the recommendation of the soils engineer. A 100% grading bond shall be submitted to the City to ensure erosion control is in place throughout all phases and stages of the grading project, subject to the approval of the City Building Official.
(7) Applicable requirements of the City and State shall be complied with in conjunction with a National Pollution Discharge Elimination System (NPDES) permit prior to the issuance of a grading permit, which may include, but is not limited to, an Erosion Control Plan, Best Management Plan (including Notice of Intent to be filed with the State Water Resources Control Board) and Construction Monitoring Program.
(Ord. 112, passed 3-4-2009)