Chapter 9.52
Hillside Development


9.52.010    Purpose

9.52.020    Applicability

9.52.030    Permit Requirements

9.52.040    Hillside Subdivision Standards

9.52.050    Site Planning and Development Standards

9.52.060    Building Design Standards

9.52.070    Hillside Development Permit

9.52.010 Purpose

The purposes of this Chapter are to:

A.    Preserve the City’s environmental and scenic resources by encouraging the retention of natural topographic features and vegetation;

B.    Recognize that as the slope of a development site increases so does the potential for environmental degradation including slope failure, and increased storm water runoff that will also increase the potential for erosion, and waterway sedimentation;

C.    Encourage appropriate road construction and grading practices in hillside areas;

D.    Encourage structures on hillside parcels to be designed with scale, massing, architectural design and detailing appropriate to maintain the visual character of hillsides as natural and open; and

E.    Recognize that commercial timber operations are allowed only in the AE, AR, and NR-TP zone districts.

9.52.020 Applicability

A.    Applicability. The requirements and guidelines in this Chapter apply to new construction or remodeling, subdivisions, new land uses, and all other proposed development on a site in the areas subject to hillside development standards as mapped in the General Plan, Figure PS-a, Hazards Map.

B.    Limitation on hillside development. No new grading, construction or development shall occur on a slope of more than 25 percent, except that:

1.    Each new lot created in areas subject to this Chapter shall contain a contiguous buildable area of at least 4,000 square feet, with a natural slope of 15 percent or less.

2.    Each existing, legally created lot which cannot meet the 15 percent slope standard may develop a buildable area of 1,500 square feet if the City determines that there is no alternative building site.

9.52.030 Permit Requirements

A proposed project that is subject to this Chapter shall be authorized by a Hillside Development Permit in compliance with Section 9.52.070 (Hillside Development Permit), in addition to any other permit required by this Land Use Code.

9.52.040 Hillside Subdivision Standards

Any proposed subdivision and any existing, legally created, undeveloped lot shall comply with the following standards.

A.    Parcel and building site.

1.    Each parcel and building site shall comply with the Section 9.52.020.B and shall adhere to the hillside development standards found in Policy PS-3c of the Arcata General Plan: 2020.

2.    A minimum of 50 percent of the area of each lot shall be designated as a natural area. All slopes greater than 25 percent shall be included in the natural area. This area shall be identified on each map that accompanies a development proposal. No grading or development shall be permitted in the natural area.

3.    Areas with slopes greater than 25 percent shall not be included in the acreage used to calculate allowable density.

B.    Roads. Each new road shall follow natural terrain contours to the maximum extent feasible to minimize grading and shall adhere to the hillside development standards found in Policy PS-3c of the Arcata General Plan 2020. Proposed driveways shall comply with the requirements of Section 9.52.050 (Site Planning and Development Standards).

9.52.050 Site Planning and Development Standards

Each structure shall be located in the most accessible, least visually prominent, most geologically stable, portion or portions of the site. Siting structures in the least prominent locations is especially important on open hillsides where the high visibility of construction as viewed from public access points (e.g., Highway 101, the Arcata Marsh, or the Arcata Plaza) should be minimized by placing structures so that they will be screened by existing vegetation, depressions in topography, or other natural features.

A.    Site access. Each driveway shall follow natural terrain contours to minimize grading, and also shall comply with the following standards.

1.    Common driveways and easements that serve more than one parcel are encouraged, and may be required in new subdivisions, to reduce the total amount of grading and pavement.

2.    Driveway drainage facilities shall be subject to the approval of the City Engineer.

3.    A driveway shall not have a grade steeper than five percent within 10 feet of a garage or carport entry or the street. Driveway finished grades shall not exceed an average of 17 percent.

4.    Driveways shall be designed to minimize grading and disruption of vegetation.

B.    Site coverage. Total site coverage by structures and other non-permeable surfaces shall match the zoning district standards.

C.    Setbacks. Building setbacks for any proposed structure shall comply with the requirements of the applicable zoning district, or shall be determined as a Condition of Approval of a Hillside Development Permit. Residential development adjacent to the Community Forest Boundary shall be governed by the following standards:

1.    No new lots shall be created which would require a residential unit to be located within 150 feet of the Community Forest Boundary; and

2.    For a lot in existence prior to the adoption of this Land Use Code, the construction of any new structure will provide the maximum building setback from the Community Forest Boundary with a reasonable building footprint as determined by the Zoning Administrator.

D.    Structure placement. Each proposed structure shall comply with the following standards:

1.    Placement of structures. Proposed structures shall comply with the following standards, to maintain the natural appearance of hillsides and ridgelines.

a.    Each structure shall be located as follows (see Figures 5-1 and 5-2): No part of a proposed structure shall appear silhouetted against the sky above the nearest ridge or knoll when viewed from the nearest downhill street, except as provided for in Subsection 9.52.050 D(2).

b.    Each structure shall be located to take advantage of existing vegetation for screening, and should include the installation of additional native plant materials to augment existing vegetation.

Figure 5-1 - Silhouetted Structure

Figure 5-2 - Location of Structure Below Ridgeline

2.    Height limit above ridgeline. Where the City determines that a legal lot existing prior to the effective date of this Section contains no feasible building site other than where a structure will extend above the ridgeline, proposed structures shall not exceed a height of 16 feet above the highest point on the ridgeline or hilltop within 100 feet of the proposed structure. See Figure 5-3.

Figure 5-3 - Highest Point Within 100 Feet of Structure

E.    View protection. A proposed structure or addition to an existing structure shall be designed and located so that it avoids blocking views from other properties to the maximum extent feasible, as follows.

1.    New structures and tall landscaping shall not be placed directly in the view of the primary living areas on a neighboring parcel unless no other location is feasible. See Figure 5-4.

Figure 5-4 - View Protection

2.    Mechanical equipment may be placed on rooftops or below a deck only if the equipment is not visible from off the site, except for unobtrusive solar collectors that are compatible with the roof line and architecturally integrated with the structure. Equipment shall also comply with the height limits in Chapter 9.44, except that satellite dishes shall be limited to 3 feet in height and television antennas to 7 feet in height for hillside developments.

3.    Story poles shall be placed prior to any new construction and prior to any notification requirements.

F.    Exterior lighting. Exterior lighting shall be properly shielded to avoid glare and the spill of light to surrounding areas. Low-level lighting and the use of multiple low profile fixtures is encouraged, as opposed to the use of fewer, but taller fixtures.

G.    Other Standards. Site planning and development for hillside areas shall also cross-reference with chapter 9.58 (Tree Preservation and Hazardous Tree Removal).

9.52.060 Building Design Standards

Building and site design shall generally utilize varying setbacks and structure heights, split-level foundations, and low retaining walls to blend structures into the terrain.

A.    Floor area ratio. The gross floor area ratio (FAR) of all structures on a parcel in the RVL or RL zone district shall comply with the requirements of the applicable zoning district, or shall be determined as a condition of approval of a Hillside Development Permit.

B.    Windows - Infill lots. Windows, balconies, and outdoor living areas generally shall be located to protect the privacy of adjacent homes and yards.

C.    Exterior wall surfaces. The apparent size of exterior wall surfaces visible from off the site shall be minimized through the use of single story elements, setbacks, overhangs, roof pitches, landscaping, and/or other means of horizontal and vertical articulation to create changing shadow lines and break up massive forms.

D.    Colors and materials. A mixture of materials and color shall be used to blend structures with the natural appearance of the hillside.

E.    Roofs. Roof pitches shall generally be placed to follow the angle of the slope; but with variations to avoid a monotonous appearance.

F.    Support structures. Support structures (for example, columns, pilings, etc.) below the lowest floor on the downhill side of a house, shall be enclosed unless visible structural members are an integral feature of the architectural design. Support structure wall surfaces shall not exceed six feet in height.

G.    Landscaping. See Chapter 9.34 (Landscaping Standards).

9.52.070 Hillside Development Permit

A.    Purpose. The Hillside Development Permit provides a review process for proposed development on hillside parcels, to ensure that a proposed project minimizes its visual and environmental impact. A Hillside Development Permit is conducted similar to that of a Minor Use Permit.

B.    Applicability. A Hillside Development Permit is required to authorize any proposed development that is subject to the requirements of this Chapter. Per Subsection 9.24.060 A.1 of this Land Use Code, development and grading on slopes greater than 15 percent in the Residential - Very Low (RVL) zoning district may be allowed only with Hillside Development Permit approval.

C.    Application filing and processing. An application for a Hillside Development Permit shall be filed and processed in compliance with Chapter 9.70 (Permit Application Filing and Processing). A Hillside Development Permit application shall include all information and materials required by Section 9.70.030 (Application Preparation and Filing), and the following additional information.

1.    Site topography. A topographic map covering the entire site, and areas on surrounding parcels within 50 feet of the site boundary. The map shall be prepared with a contour interval of two feet, and shall include:

a.    The proposed building site;

b.    Slopes less than or equal to 10 percent;

c.    Slopes greater than 10 percent and less than 15 percent;

d.    Slopes greater than 15 percent and less than 20 percent;

e.    Slopes greater than 20 percent and less than 25 percent; and

f.    Slopes greater than 25 percent.

2.    Geotechnical report. A preliminary geotechnical report that identifies and proposes mitigation measures for any soils or geological problems that may affect site stability or structural integrity. Depending upon the site characteristics and project design, a final geotechnical report may also be required.

3.    Constraints analysis. For properties determined by the City to potentially have sensitive environmental resources including endangered plants or animals or a wildlife corridor, a qualified professional approved by the City shall prepare a site constraints analysis. The report shall include proposed mitigation measures to effectively protect identified important biological features.

D.    Project review and notice. A Hillside Development Permit shall be reviewed, have public notice provided, and be decided in the same manner as a Minor Use Permit in compliance with Section 9.72.080 (Use Permit and Minor Use Permit).

E.    Required findings. The City may approve, conditionally approve, or disapprove a Hillside Development Permit application, and shall record the decision and the findings upon which the decision is based. The City may approve a Hillside Development Permit only after first finding all of the following:

1.    The proposed project complies with the requirements of this Chapter and all other applicable provisions of this Land Use Code;

2.    The proposed project is consistent with the General Plan and any applicable specific plan;

3.    The establishment, maintenance, or operation of the use will not be detrimental to the public health, safety, or general welfare;

4.    The design, location, and size of proposed structures will be compatible with the existing and future land uses in the vicinity, in terms of aesthetics, character, scale, and view protection; and

5.    The placement of proposed structures on the site avoids slopes over 15 percent to the maximum extent feasible.

F.    Exceptions to standards. The review authority may grant an exception to the standards of this Chapter as part of Hillside Development Permit approval only where it first finds that:

1.    The exception is either necessary to allow a house with floor area of at least 1500 square feet on a site with excessive slope, Community Forest Boundary setback constraints, or other environmental constraints; or

2.    The exception will result in less visual impact than would development in compliance with the standard being adjusted.

G.    Conditions of approval. In approving a Hillside Development Permit, the City may impose any conditions it deems reasonable and necessary to ensure that the approval will comply with the findings required by Subsection E.

H.    Post approval procedures. The procedures and requirements in Chapter 9.79 (Permit Implementation, Time Limits, and Extensions), and those related to appeals in Chapter 9.76 (Appeals), shall apply following the decision on a Hillside Development Permit.