Ridgeline Preservation and Hillside Development Guidelines

Purpose

The provisions of the Ridgeline Preservation and Hillside Development Ordinance are intended to implement the goals and policies of the General Plan in relation to land use, densities, open space and community character in furtherance of the General Plan. It is the intent of this section to regulate the development and alteration of hillside areas and ridgelines to minimize the adverse impact of hillside development and to provide for the safety and welfare of Bonsall while allowing for the reasonable development of hillside areas through the following methods:

1. Provide hillside development standards to maximize the positive impacts of site design, grading, landscape architecture and building architecture, and provide development consistent with the goals and policies of the General Plan.

2. Provide ridgeline preservation and development standards to protect ridges within Bonsall minimize the adverse impacts of development.

3. Maintain the essential natural characteristics of the area such as major landforms, vegetation and wildlife communities, hydrologic features, scenic qualities and open space that contribute to a sense of place.

4. Retain the integrity of predominant off-site and on-site views in hillside areas in order to maintain the identity, image and environmental quality of Bonsall.

Applicability

The provisions of the Ridgeline Preservation and Hillside Development Ordinance shall be applied to parcels of land having average slopes of ten (10) percent or more. The provisions of these regulations shall apply to all projects relating to grading permits, building permits, parcel maps, tentative tract maps, conditional use permits and plans for development review. General Plan amendments and zone changes affecting hillside land shall also be subject to review in accordance with the provisions of these regulations.

Properties subject to this Program

1. New structures

2. Modifications to existing structures located on a major or minor ridgeline or on hillside slopes of 15% or more.

3. Future building sites identified on tentative maps

4. Final parcel maps

5. Subdivision maps

Hillside Plan Review/Permit Requirements

A. Plan review. In reviewing hillside development plans, the reviewing authority shall act to attain the following objectives within the intent and scope of these regulations. All proposed development project on land with an average slope of ten (10) percent or greater, as determined to be applicable by the Director of Planning, shall be subject to the issuance of a permit for hillside plan review.
1. Natural topographic features and appearances shall be conserved by means of landform grading so as to blend any manufactured slopes or required drainage benches into the natural topography.

2. Significant, natural, topographic prominent features shall be retained to the maximum extent possible.

3. Clustered sites and buildings shall be utilized where such techniques can be demonstrated to substantially reduce grading alterations of the terrain and to contribute to the preservation of trees, other natural vegetation and prominent landmark features and are compatible with existing neighborhoods.

4. Building setbacks, building heights and compatible structures and building forms that would serve to blend buildings and structures with the terrain shall be utilized.

5. Plant materials shall be conserved and introduced so as to protect slopes from slippage and soil erosion and to minimize visual effects of grading and construction on hillside areas, including the consideration of the preservation of prominent trees and, to the extent possible, reduce the maintenance cost to public and private property owners.

6. Curvilinear street design and improvements that serve to minimize grading alterations and emulate the natural contours and character of the hillsides shall be utilized.

7. Grading designs that serve to avoid disruption to adjacent property shall be utilized.

8. Site design and grading that provide the minimum disruption of view corridors and scenic vistas from and around any proposed development shall be utilized.

B. Application submittal and project review. Hillside plan review projects shall be submitted in compliance with the hillside plan review submittal requirements, which are available in the Planning and Building Services Department. Upon receipt of applications for hillside development permits and accompanying necessary information, there may be a preliminary meeting with staff to review comments on proposed projects and determine the level of the review process.

1. Director of Planning review. The Director of Planning shall review all site development applications and shall impose conditions deemed appropriate when one or more of the following activities are proposed:

a. Development activities on natural slopes which are greater than ten (10) percent average but less than fifteen (15) percent average on all or part of the developable portions of the site.

b. Grading excavations or fills or any combination thereof equal to or exceeding one hundred (100) cubic yards, but less than one thousand five hundred (1,500) cubic yards.

2. Planning Commission review. The Planning Commission shall review site development applications and shall impose conditions deemed appropriate when one or more of the following occurs:

a. The proposed project is referred to the Planning Commission by The Director of Planning.

b. Development activities on natural slopes which are greater than fifteen (15) percent average on all or part of the developable portions of the site.

c. Grading excavations or fills or any combination thereof exceeding one thousand five hundred (1,500) cubic yards.

d. The proposed project includes a discretionary application/request which requires the approval of the Planning Commission. In such cases, the request shall be reviewed simultaneously with the Hillside plan review application. The whole of the project shall be considered, and dividing the project into parts to achieve different levels of review shall not be allowed.

e. The Planning Commission may issue a determination on discretionary requests within its decision-making authority.

C. Ridgeline Preservation and Hillside Development Guidelines. All projects shall be reviewed for applicability with the criteria defined in the Ridgeline Preservation and Hillside Development Guidelines.

D. Innovative Applications. To recognize that decisions may need to be made in individual developments to balance achievement of the General Plan goals, and to encourage innovation and creativity for projects of high quality, although they do not meet all of the precise conditions of this ordinance, there are alternative vehicles for project processing. These include a planned development, specific plan or conditional use permit in accordance with the provisions of this Code to individually tailor the design and standards to suit a given site.

Projects which require minor grading or are limited in scope such as those regarding yard areas for pool/spa construction, landscaping, additions to existing structures or construction of accessory structures may be approved by The Director of Planning through a grading permit or building permit without hillside plan review. Projects which require grading of large, flat areas, such as tennis courts or riding rings, may be reviewed by The Director of Planning or the Planning Commission, depending on the amount of grading in slope areas and the average slope consistent with the levels of hillside plan review as described in this section.

Development Standards

The development standards shall apply to any use, development or alteration of land included in these regulations.

A. Ridgeline Development Classification. Significant ridgelines are the ridgelines that surround or visually dominate the valley landscape either through their size in relation to the hillside or mountain terrain or which they are a part; their visual dominance as characterized by a silhouetting appearance against the sky; as a significant natural backdrop feature or separation of communities; through visual dominance due to proximity and view from existing development or major corridors; or as an area of significant ecological, historical or cultural importance such as those which connect park or trail systems.

B. Significant Ridgeline Classification. Development use regulated on significant ridgelines due to their aesthetic, visual, ecological, historical or cultural importance to maintain a sense of place and identity and to protect the visual quality and natural environmental the important hills, canyons and valleys which compose the Bonsall Planning area. Two categories of significant ridgelines have been identified. Significant ridgelines shall not be altered by grading or improvements except as approved through a hillside plan review permit.

1. Primary Ridgelines. Primary ridgelines are those ridgelines which can be seen with a sky backdrop from any publicly designated road in the community of Bonsall (see appendix)

2. Secondary Ridgelines. Secondary ridgelines are those ridgelines which are characterized by any combination of significant ridgeline criteria as identified in subsection A above, but are secondary in nature to primary ridgelines due to the following features:

a. Smaller size and prominence of a feature or branch of a primary ridgeline;

b. Silhouette of a ridgeline against the open sky on a smaller size hill or silhouette of a ridgeline on a smaller hill which is back-dropped by a significant ridgeline.

C. Significant Ridgelines Map. Significant ridgelines are mapped according to their classification as described in this section. The map is herein incorporated by reference and will be on file in the Planning Department.

D. Ridgeline Preservation. The Official Ridgeline Preservation Map identifies crests of significant ridgelines in the Bonsall. The precise area to be preserved will be designated on a case- by-case basis. No grading or improvements shall occur within these designated areas except as approved by a hillside plan review permit. Any development plan which touches, crosses, includes or affects any primary ridgeline shall include plans for the preservation for all or part of such primary ridgeline in its natural state. No engineered slopes, housing construction, streets, utilities or other man-made features shall be permitted within primary ridgeline areas. Encroachments may be granted if the Planning Commission finds that the encroachment onto a primary ridgeline will be in compliance with the criteria in this chapter. Secondary ridgelines shall also be considered for hillside development proposals. Grading in these areas shall be reviewed for conformance with the design criteria of this chapter as reviewed and approved by a hillside plan review permit. The following process shall be observed when reviewing plans for hillside development.

1. Ridgeline areas shall be reviewed in conjunction with the landform of which they are a part, pursuant to the provisions of hillside plan review.

2. Determination of significant ridgelines or areas of ridgelines where development will be permitted shall be determined for each applicable case through visual analysis by any combination of the following techniques as determined by The Director of Planning:

a. Project simulation using computer-aided, three-dimensional modeling coordinated with photography showing before and after conditions;

b. Scaled, three-dimensional model showing before and after conditions;

c. Scaled, sight-line analysis drawings with views from selected locations showing precise visual impacts of the development proposal. This visual analysis technique will be applied to projects having limited scope and low probability for significant impacts, such as construction of single dwellings not within a significant ridgeline area, additions to pre-existing development on significant ridgelines where similar encroachments have previously occurred and other similar situations.

E. Innovative Applications for Significant Ridgelines. Certain uses may be permitted on significant ridgelines to promote the public health, safety and general welfare, with the approval of a conditional use permit. Such uses or development may include but shall not be limited to the following: apiaries, aviaries, historical landmarks, observatories, open space/conservation areas, parks and recreation areas, publicly and privately-operated transmission facilities, public street access (including utility extensions underneath the street), public buildings, recreational camps, riding academies or stables, trails, water tanks (screened) and innovative development. For the purposes of this section of the UDC, an innovative development shall be defined as a proposed use or development that demonstrates creative and imaginative site design resulting in a project that will compliment the community character and provide a direct benefit to current and future community residents of not only the proposed use or development, but the residents of Bonsall as a whole utilizing unique grading techniques, imaginative project site design and spacing of development that significantly exceeds the minimum standards identified in the Bonsall Preservation and Hillside Development Guidelines.

1. Criteria for Innovative Applications for Significant Ridgelines. Encroachment onto a significant ridgeline shall be permitted when the Planning Commission, following a public hearing, issues written findings based upon the following evidence:

a. The proposed use is proper in relation to adjacent uses, the development of the community and the various goals and policies of the General Plan.

b. The use or development will not be materially detrimental to the visual character of the neighborhood or community, nor will it endanger the public health, safety or general welfare.

c. The appearance of the use or development will not be different than the appearance of adjoining ridgeline areas so as to cause depreciation of the ridgeline appearance in the vicinity.

d. The establishment of the proposed use or development will not impede the normal and orderly development and improvement of surrounding property, nor encourage inappropriate encroachments to the ridgeline area.

e. It has been demonstrated that the proposed use or development will not violate the visual integrity of the significant ridgeline area through precise illustration and depiction as required in subsection D above, Ridgeline Preservation

f. The use or development should minimize the effects of grading to insure that the natural character of ridgelines are preserved.

g. The proposed use or development maintains the appearance of natural ridgelines with uses or development consistent with density requirements.

h. The proposed use or development utilizes or creates unique grading techniques, imaginative project site design and spacing of development that significantly exceeds the minimum standards identified in the Bonsall Ridgeline Preservation and Hillside Development Guidelines.

i. The proposed use or development should be designed to mimic the existing topography to the greatest extent possible.

j. The proposed use or development demonstrates creative and imaginative site design resulting in a project that will compliment the community character and provide a direct benefit to current and future community residents of not only the proposed use or development, but the residents of Bonsall as a whole.

k. The proposed use or development should not alter natural landmarks and prominent natural features which enhance the character of ridgelines in their natural environment.

2. Corrective work. Nothing in this section shall prohibit The Director of Planning from authorizing grading deemed necessary to correct natural, hazardous conditions that are brought to Bonsall’s attention, in which case the applicant will investigate possible alternatives with subsequent review by The Director of Planning or the Planning Commission.

F. Hillside Classifications. Hillside categories have been identified by percentage of average slope in the following categories:

1. Average slopes under ten (10) percent are considered relatively flat and would not cause any conditions necessary for the implementation of the Ridgeline Preservation and Hillside Development Ordinance.

2. Projects with slopes which average ten (10) percent or greater qualify for hillside plan review.

H. Division of Area. Where there exists a dramatically different landform character in the topography of any one site, the site may be divided into several distinct areas for purposes of slope determinations. An average density may be calculated separately for unique areas on site upon approval of The Director of Planning.

I. Grading Design.

1. No graded or cut embankment with a slope greater than two feet horizontal to one foot vertical shall be located adjacent to a publicly maintained right-of-way. The applicant shall provide suitable guarantees satisfactory to the reviewing authority for landscaping and perpetual maintenance, at no cost to the community, of all slopes outside of the public right-of-way. Major public roads, such as those identified in the General Plan Circulation Element, may require slopes steeper than 2:1. In such an event, slopes steeper than 2:1 may be allowed, provided that a geotechnical study is prepared verifying the feasibility of such slopes.

2. The overall slope, height or grade of any cut or fill slope shall be developed to appear similar to the existing natural contours in scale with the natural terrain of the subject site.

3. Where any cut or fill slope exceeds 10 feet in horizontal length, the horizontal contours of the slope shall be developed to appear similar to the existing natural contours.

4. Grading shall be balanced on site whenever possible to avoid excessive cut and fill and to avoid import or export.

5. Grading shall be phased so that prompt re-vegetation or construction will control erosion. Where possible, only those areas that will be immediately developed, resurfaced or landscaped shall be disturbed.

6. No excavation or other earth disturbance shall be permitted on any hillside area prior to the issuance of a grading permit, with the exception of drill holes and exploratory trenched for the collection of geologic and soil data. These trenches are to be properly backfilled and, in addition, erosion treatment shall be provided where slopes exceed 20%.

7. Retaining walls in the back of the pad on a lot shall be a maximum of eight (8) feet in height. Retaining walls in the side yard of a lot shall be a maximum of six (6) feet in height. If greater height is desired, two (2), four (4) foot walls may be used with planters in between the walls to soften the effect within a minimum horizontal spacing of three (3) feet. Adjacent to any right-of-way, retaining walls shall be a maximum of six (6) feet high or a total of eight (8) feet if two (2), four (4) foot walls are used in combination with a minimum horizontal spacing of five (5) feet.

J. Landscape Design.

1. Landscape coverage and stabilization of graded slopes shall be selected and designed to be compatible with surrounding natural vegetation. Plant material shall be selected according to compatible climatic, soil and ecological characteristics of the region. A county-approved irrigation system shall be utilized for plant establishment, but plant materials that require excessive water after becoming established shall be avoided. Native plant material or compatible, non-native plant material shall be selected.

2. The location of all existing trees of four (4) inch caliper or greater, as measured four and one-half feet from the ground, shall be shown on plans submitted for approval. The reviewing authority shall designate all trees to be saved or removed.

3. All cut and fill slopes shall be planted and irrigated with an automatic irrigation system to prevent erosion. All cut or fill slopes exceeding five (5) feet vertical height shall be planted with adequate plant material to protect the slope against erosion. Planting shall be in the ratio at least one shrub per one hundred (100) square feet of natural slope area and one tree per one hundred fifty (150) square feet of actual slope area, with ground cover to completely cover the slope within six (6) months from planting. All plants shall be drought-resistant and shrubs shall be a minimum one gallon size, unless hydroseeded. All trees shall be minimum five (5) gallon size. Slopes less than five (5) feet in height shall be planted with ground cover to cover the slopes completely within six (6) months of planting. However, The Director of Planning may require fifteen (15) gallon size trees on a case by case basis.

4. Privacy walls and fences not exceeding six (6) feet in height are permitted adjacent to structures in order to provide a private outdoor area. A minimum flat area from top or toe of slope of three (3) feet shall be maintained to face of wall on common area maintenance slopes with slope heights of thirty (30) feet or greater. All fences which are adjacent to or visible from public roads or major public spaces shall be of decorative masonry or other approved materials with minimum five (5) foot landscape area on the street side of the wall or fence. The use of indigenous rock and colors or materials which blend with the surrounding natural landscape is preferred.

5. Access easement areas a minimum of five (5) feet wide shall be provided for uphill and downhill slope maintenance areas and should be located no more than one thousand (1,000) feet apart.

6. A fuel modification plan shall be required by The Director of Planning for all hillside plans that abut natural open space.

7. The project shall be designed to incorporate fire prevention and safety measures pursuant to the provisions of the Uniform Fire Code and the Ridgeline Preservation and Hillside Development Guidelines.

Plan Certification.

A. Grading Plan Certification. Upon completion of rough grading work and prior to any excavation for foundations or structures an as-graded plan prepared and certified by the licensed civil engineer who prepared the approved grading plans shall be submitted to the Planning Divisions for review and approval. The as-graded plans shall include original ground surface elevations, as-graded surface elevations and all other features that were a part of the approved grading plan. The engineer shall provide certification on the as-graded plan that the work was done in accordance with the approved grading plan and grading requirements.

B. Landscape Plan Certification. Landscape and irrigation plans shall be prepared by a licensed landscape architect and shall be submitted to and approved by the Planning Department and the Parks, and Recreation Department. A licensed landscape architect shall certify that the planting plans comply with the landscape requirements. The landscape architect or irrigation consultant shall certify that the irrigation plans are designed in compliance with landscape requirements.

Appendix

Designated Public Roads in Bonsall

1. SR 76
2. Gopher Canyon Road
3. Little Gopher Canyon
4. West Lilac Road
5. Camino Del Rey
6. Olive Hill Road
7. Old River Road
8. Osborne