Yorba Linda City Zoning Code
CHAPTER 18
30 HILLSIDE DEVELOPMENT
§ 18.30.010 Purpose.
The purpose of this chapter is to provide standards and guidelines for hillside development.
(Ord. 2004-884; Ord. 2019-1056 § 3)
§ 18.30.020 Applicability.
These regulations shall apply to all portions of property within the City having a slope gradient, whether natural or manufactured, of 15 percent or greater.
(Ord. 2004-884; Ord. 2019-1056 § 3)
§ 18.30.030 Permits required.
Prior to development on any lot subject to this chapter, such development shall be reviewed for compliance with the standards and guidelines set forth in Section 18.30.040. For the purposes of this chapter, development shall include any development that requires a grading permit. If development on any lot subject to this chapter would not otherwise require review pursuant to Chapter 17.08 or 18.36, such development shall, nonetheless, be subject to the design review process set forth in Chapter 18.36.
(Ord. 2004-884; Ord. 2019-1056 § 3)
§ 18.30.040 Standards and guidelines.
A.
Site Design Principles.
1.
Most of the hillside sites are highly visible from distant locations. Therefore, views of the site from the neighborhood and other off-site locations should be given careful consideration.
2.
Massive grading and single retaining walls in excess of six feet in height should be avoided in order to preserve a more natural slope appearance.
3.
The buildings located near hillside rims have higher visibility. The buildings should be partially screened with landscaping to minimize the "wall" effect.
4.
Significant trees and other vegetation, which contribute to the aesthetics of the site and surrounding area, should be preserved.
5.
Natural hillsides and ridgelines should be preserved to the extent feasible. The usual impacts of grading should be softened through designs which incorporate slope undulation, blending and other features to reflect the natural terrain.
B.
Hillside Grading and Drainage.
1.
Retaining walls visible from off-site should be no higher than six feet and shall be planted with vines and/or other landscape screening. Where it is determined that higher retaining walls are required, the Planning Commission may approve a tier of up to three such walls (nine to 12 feet in height each) placed one above the other, provided a minimum of four feet of horizontal landscaped terrace is placed between each set of walls. The Planning Commission may approve alternative retaining wall designs where it is determined that the alternative wall design is a better design both for engineering and aesthetic reasons.
2.
Drainage devices, such as terrace drains, benches and downdrains, should be located underground or placed in locations of least visibility on slopes. The downhill side of a drain should be bermed to conceal it. Natural swales leading downhill are good locations for down drains. Any visible drains should be as close as possible to natural soil color. Visible concrete drains should be color tinted and screened with planting.
C.
Planting Design for Hillsides.
1.
Common open space and landscaped areas in any zone which are maintained by homeowners' associations and/or commercial/industrial owners or management companies are subject to review under these guidelines.
2.
Plant Selection.
a.
The plant materials should be selected for erosion control effectiveness, fire resistance, drought tolerance, and ability to enhance the color and texture of the surrounding landscape.
b.
The location and heights of plantings should follow the downhill alignments of taller trees.
c.
Less dense, open trees that do not block views should be used. Exceptional care is to be used to locate trees near property lines or other locations that have less significant view sensitivity.
3.
Planting Techniques for Graded Slopes.
a.
The irregular spacing of vegetation is encouraged to achieve a natural appearance on graded slopes. The inclusion of shrubs that vary in height between tree stands will provide aesthetic diversity.
b.
Whenever possible, trees should be located in swale areas to more closely reflect natural conditions and gather surface runoff for plant irrigation.
c.
Selection of low-growing covers (12-inch maximum height) and sprawling shrubs (12- to 36-inch maximum height) shall be used in the initial five feet of slope vertical elevation for large slopes as well as slopes no greater in height than 10 feet. Gradation of maximum height shrubs of approximately 36-inch maximum height should generally be used in the five- to 40-foot vertical elevation areas. Taller shrubs can be intermixed in slope areas above the 40-foot area. Care in selection of shrubs near the top of slopes for view lots is critical to the protection of views.
4.
Transitional Slope Plantings.
a.
Transitional slope plantings should be used between the domestic plantings and the native, flammable brush of undisturbed areas. The goal is to reduce the rate of approaching fire within the transitional zone by reducing the fire's fuel supply.
b.
In any location where natural existing vegetation areas are adjacent to proposed development, a Fuel Modification Plan shall be developed delineating a wide strip of land (usually a minimum of 170 feet) where combustible vegetation has been removed and/or modified and partially or totally replaced with drought-tolerant, fire-resistive plants to provide an acceptable level of risk from wildland fires.
c.
Fuel modification planting schemes shall be prepared, clearly indicated on a Fuel Modification Plan, which is subject to review and approval of the Orange County Fire Authority, with typical zones as follows:
i.
Setback zone, with no combustible construction, typically a 20-foot Zone A;
ii.
Irrigated zone, consisting of irrigated landscaping, typically a 50-foot Zone B;
iii.
Thinning zones, where natural vegetation is thinned by reduced amounts as the zones move away from development. Thinning zones can be defined as areas of reduced fuel loads by removal of a specified percentage of vegetation (greater percentage for the closest of the two zones, lesser percentage for the final zone), typically a 50-foot Zone C and a 50-foot Zone D.
D.
Residential Development Standards in Hillside Areas. Any residential tract or individual residential unit development within hillside areas, shall conform to the following standards:
1.
Ridgelines shall be preserved in their natural state to the degree possible.
2.
Streets, both public and private, shall be developed below the crest of a natural ridgeline.
3.
Building pads shall not be located so as to be on the crest of a natural ridgeline.
4.
Any construction shall be done in a manner so as a dwelling, roofline or any component part of the construction shall be superimposed against another land mass and shall not be visible against a horizon or the sky when viewed from the canyon floor.
5.
Tract and parcel maps for the purposes of residential construction shall include a variety of house styles, heights, roof elements and other design features.
6.
Natural earth tones and materials shall be used; use of bright colors, including stark white, shall be discouraged.
7.
Terraces, terrace drains, down-drains and other similar structures, shall incorporate the use of natural rock or other man-made design feature that has the appearance of a natural material.
8.
Any manufactured slope shall be contoured in a manner to appear to have a natural grade.
E.
Within Viewscape of Chino Hills State Park. For any proposed residential development that is determined to be viewed from any point within Chino Hills State Park, the grading and landscaping plans shall include, for each lot so determined to be viewed, specific measures, including height limits, setbacks, landscaping, berms and/or other measures which will assure that any structure built on the lot will not be viewed from Chino Hills State Park or otherwise be screened to the extent feasible.
(Ord. 2004-884; Ord. 2019-1056 § 3)
§ 18.30.050 Application required.
The property owner, his or her designated representative or agent shall complete and submit any applications required pursuant to Section 18.30.030 and shall obtain a decision on the applications prior to instituting any work. Application shall be made upon the forms and in the format provided by the Community Development Department and shall be accompanied by a fee as established by resolution of the City Council for the application. Modifications to a required application shall be subject to the same requirements as the original.
(Ord. 2004-884; Ord. 2019-1056 § 3)