PLANNING COMMISSION
AGENDA REPORT
AGENDA ITEM NUMBER: 7.1
MEETING DATE: April 26, 2022
CASE/FILE NUMBER: Vesting Tentative Tract Map No. 54081, Development Review, Tree Permit and
Conditional Use Permit Planning Case No.
PL2017-203
PROJECT LOCATION: Southern terminus of Crooked Creek Drive, east of the SR-57 Freeway, Brea Canyon Road and
Brea Canyon flood control channel and north of
the City’s southern boundary (Los Angeles
County Assessor’s Parcel Number 8714-028-
003)
GENERAL PLAN DESIGNATION: Low Density Residential (RL)
ZONING DISTRICT: RL-PD (Low Density Residential Planned Development)
PROPERTY OWNER: Cathay View Development, LLC
701 S. San Gabriel, Suite D
San Gabriel, CA 91176
APPLICANT: New Bridge Homes
500 Newport Center Drive, Suite 570
Newport Beach, CA 92660
RECOMMENDATION:
Adopt the attached resolution (Attachment A) recommending that the City Council adopt the Mitigated Negative Declaration and Mitigation Monitoring and Reporting Program.
Adopt the attached resolution (Attachment B) recommending that the City Council approve Vesting Tentative Tract Map No. 54081, Development Review, Tree Permit CITY OF DIAMOND BAR ~ 21810 COPLEY DRIVE ~ DIAMOND BAR, CA 91765 ~ TEL. (909) 839-7030 ~ FAX (909) 861-3117
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and Conditional Use Permit No. PL2017-203, based on the Findings of Fact, and subject to the conditions of approval listed within the draft resolution.
SUMMARY:
The applicant is requesting approval of a residential subdivision that includes the development of seven single-family residences and associated infrastructure, including a southward extension of Crooked Creek Drive on a 12.9-acre undeveloped site. Five of the seven proposed residential structures include an attached accessory dwelling unit (ADU). The following entitlements are requested:
1. Vesting Tentative Tract Map No. 54081 (“VTTM No 54081”) to subdivide the subject property into nine parcels for the following purposes: seven (7) single-family residential lots; one lot reserved for a trailhead that anticipates the future improvement of Los Angeles County-owned easements to provide access to the Schabarum Trail system; and one lot containing approximately 10.4 acres of preserved open space and associated maintenance access. Access to the lots is proposed by extending and dedicating Crooked Creek Drive for public right-of-way purposes.
2. Development Review to approve the site, architectural and landscape design of a new residential development to ensure consistency with the General Plan, Development Code, and compliance with all applicable and design guidelines and standards.
3. Tree Permit to remove 62 existing protected trees consisting of 58 Southern California black walnuts and four coast live oaks, and to replace them at a 3:1 ratio with 201 Southern California black walnuts and 12 coast live oaks, totaling 213 replacement trees to be planted on-site.
4. Conditional Use Permit to approve development on a site subject to a Planned Development Overlay District and allow modifications to the following development standards:
· Increase the exposed retaining wall height limit from six feet to 17 feet; · Reduce the minimum front setback requirement for Lots 4 and 5 from 20 feet to 14 feet and 13.75 feet, respectively; and
· Reduce the minimum lot size requirement for Lots 1 and 3 from 10,000 to 8,294 square feet and 8,482 square feet, respectively.
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Site (Plan View) Aerial
BACKGROUND:
SITE AND SURROUNDING GENERAL PLAN, ZONING, AND LAND USES Site Characteristics
The project site consists of approximately 12.9 acres of undeveloped area which supports nonnative grassland, coast live oak woodland and Southern California black walnut woodland. Elevations within the site range from approximately 645 feet to 835 feet above sea level (i.e., an overall elevation difference of 190 feet). The topographic profile is composed of steep hillside terrain to the east, gently rolling terrain to the north, and areas that are relatively flat valley to the west, with a steep drop to the Brea Canyon Channel. The western portion of the project site, where most of the development is proposed to occur, has elevations ranging from 645 feet to 720 feet above sea level.
The Project site is legally described as Lot 4 of Parcel Map as per book 74, pages 3-4, and the Assessor’s Parcel Number (APN) is 8714-028-003.
The image below highlights the subject property:
Site (plan view) aerial
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Aerial view
The project site is surrounded by existing single-family residential development to the north; single-family residences along Running Branch Road to the east; the Brea Canyon Flood Control Channel and single-family residences along Castle Rock Road to the west; and undeveloped land (Tonner Canyon) within unincorporated Los Angeles County, through which a Southern California Edison (SCE) tower and associated electrical lines traverse, to the south.
General Plan Designation Zoning
District Land Use
Site Low Density Residential (RL) RL-PD Undeveloped
North Low Medium Density
Residential (RLM) RLM Single-Family Residential
South Diamond Bar sphere of
influence (unincorporated) N/A Undeveloped
East Low Density Residential (RL) RL Single-Family Residential West Low Medium Density
Residential (RLM) RLM Flood Control Channel & Single-Family Residential
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Project Site viewed from the current terminus of Crooked Creek Drive Adjacent property to the north
(3722 Crooked Creek Dr.)
Adjacent property to the north
(3723 Crooked Creek Dr.)
BACKGROUND:
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2007 Entitlements
On February 20, 2007, the City Council approved a 16-lot residential subdivision on the subject site which included a Vesting Tentative Tract Map, Zone Change from “R1-10,000” to “Low Density Residential Planned Development” (RL-PD); a Conditional Use Permit for development in a hillside area and subject to the Planned Development Overlay District; a Variance to increase maximum allowable exposed height limit for retaining walls from six feet to ten feet; and a Tree Permit to remove 269 protected trees (197 trees were considered dead and 72 trees were to be mitigated). Of the 72 trees, 43 were coast live oaks and 29 were California black walnut trees. Additionally, 11.5 acres of mixed coast live oak and California walnut woodland would have been impacted. This proposal anticipated a total of 98,000 cubic yards of cut and 86,000 cubic yards of fill.
The entitlements were valid for up to ten years, meaning that the developer had until February 20, 2017 to record the final map, or the entitlements would expire. 2007 approved map with 16 residential lots
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First redesign (2018) - 12 residential lots
On October 24, 2014, the property was sold to the current owner, Cathay View Development, LLC (“CVD”). CVD hired a new consulting team to complete and record the Final Map. During the plan check process, the project team identified a variety of technical deficiencies in the previously-submitted improvement plans and the project expired on February 20, 2017. All entitlements from the previous project have expired except for the zone change, which was adopted by ordinance, and became effective immediately upon adoption. The project team then began work on a complete redesign of the project.
Expiration of 2007 Entitlements and Commencement of New Design Process In 2018, after two developer-hosted neighborhood meetings, the applicant submitted a subdivision map with 12 residential lots. The design included a pair of tiered retaining walls on the western portion of the project area (i.e., the Brea Canyon Channel side) with heights of each wall reaching 12’-6” and 15’-6”. On the eastern portion of the project area (i.e., the hillside), five tiers of 20-foot high retaining walls were proposed, which would have resulted in 100 vertical feet of exposed wall surfaces. This design anticipated a total of 90,000 cubic yards of cut and 52,000 cubic yards of fill.
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2019 design - 11 residential lots
In 2019, the design was further reconfigured and the number of residential lots was reduced from 12 to 11. The reduction in grading reduced the encroachment into existing native habitat, and reduced the visual impact of the previous retaining wall configuration. Additionally, the Crooked Creek Drive extension was narrowed to reduce grading impacts. Retaining walls facing the Brea Canyon Channel were reduced to four feet. On the eastern portion of the project area (i.e., the hillside), the lineal footage of the five tiers of retaining walls was reduced, and the height of each wall was reduced to 15 feet. Lastly, split-level, step-down building pads were introduced to reduce grading impacts. Total earthwork resulting from this revised design was reduced to 35,000 cubic yards of cut and 13,000 cubic yards of fill.
After receiving further community and staff feedback, the applicant made additional, substantive revisions to the subdivision design, and formally submitted an application to the City. The remainder of this staff report describes and analyzes project submitted for Planning Commission and City Council consideration.
PROJECT DESCRIPTION:
A. Vesting Tentative Tract Map
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Proposed 2022 design – 7 residential lots
The Vesting Tentative Tract Map presented for approval proposes to subdivide the property into nine lots to accommodate seven lots for the individual sale of production homes, one lot designated for a trailhead, and one 10.4-acre lot to be retained as a preserved open space. The trailhead and preserved open space area will be owned in common by the future homeowners association (HOA). The proposed map includes a 43-foot-wide southward extension of Crooked Creek Drive, which would be dedicated to the City as a public roadway.
The acreages corresponding to the above-listed uses are provided in the table below:
Use Units Proposed Area
Single-Family Detached Lots 7 82,662 sq. ft.
Trailhead (Lot A) - 653 sq. ft.
Open Space (Lot B) - 451,453 sq. ft.
Total 534,768 sq. ft.
Residential lot sizes range from 8,340 square feet to 16,826 square feet, with minimum dimensions of 65 feet in width and 93 feet in depth.
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B. Residences
The applicant proposes to construct seven for-sale single-family homes on individual lots with the following features:
· Three-stories with a maximum building height of 34 feet; · Three floor plans with livable areas ranging from 3,893 – 4,814 square feet; · Front porches and verandas; and
· Attached accessory dwelling units (ADUs) ranging from 499 – 600 square feet.
Five homes will each include an attached ADU. The Development Code (in accordance with State law) defines an ADU as “an attached or a detached residential dwelling unit which provides complete independent living facilities for one or more persons. It shall include permanent provisions for living, sleeping, eating, cooking, and sanitation on the same parcel as the single-family dwelling is situated.” Each ADU will be attached to the primary residence with a separate entrance, living area, kitchen, dining room, bedroom, bathroom and laundry unit. All utilities serving an ADU shall be common to and dependent on the primary residence.
C. Access and Circulation
Each proposed lot will have access from the proposed extension of Crooked Creek Drive, which will terminate as a cul-de-sac at the south end of the project site. The roadway alignment is primarily guided by site-specific topographic and geotechnical factors, which results in the westward curvature that follows the contours of the adjacent toe of slope. Because the Crooked Creek extension is proposed to be a public street, the project entrance will not be gated.
The 43-foot-wide right-of-way consists of 36 feet of roadway width between the curbs, and a 6.5-foot sidewalk on the west side of the street, along the frontages of Lots 2 through 7. Although the roadway width and cul-de-sac radius meet City and Fire Department standards for public streets with parking on both sides, the proposed design deviates from the City standard by deleting the sidewalk on the east side of the street.
Staff supports this roadway design modification because it reduces the amount of grading and retaining walls required, and because there are no homes along the substantial majority of the easterly street frontage.
The proposed street configuration, widths, and turning radii have been reviewed and accepted by the Public Works Department and the County of Los Angeles Fire Department.
D. Trailhead and Open Space
The City’s Trail Master Plan envisions the southern end of the project site to incorporate a trailhead, which would serve as a future connection to the County Schabarum Trail.
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Lot “A” will be reserved for the trailhead and the developer will be required to design and construct the trailhead improvements per City standards with a sign, pergola and bench. Improvements for the trailhead are set forth as conditions in the draft resolution.
Until such time that the trail County trail improvements are completed, the HOA will be required to maintain the trailhead. The southern boundary of the project site will be gated with a six-foot high wrought iron fence to prevent trespassing until such time when connection to the County Schabarum Trail is established. Once the County establishes the trail extension, the fencing will be removed, and the trailhead lot will be dedicated to the City. The provisions for the trailhead improvements and dedication will be recorded on the final tract map and CC&Rs pursuant to the recommended conditions of approval.
The 10.4 acres of preserved open space area will remain undeveloped in perpetuity, with the exception of the planting of mitigation trees and installation of temporary irrigation as part of the project. Further discussion on the mitigation trees is in the Tree Permit section below. The open space area will be maintained by the HOA.
ANALYSIS:
Review Authority (Diamond Bar Municipal Code Sections 21.20.130, 22.48,
22.38.110 and 22.58.040)
As stated, the Project requires the approval of four discretionary entitlement applications. The Vesting Tentative Tract Map (VTTM) requires City Council approval, and the other three entitlements (Development Review, Tree Permit and Conditional Use Permit) require Planning Commission approval. Section 22.48.030 of the Development Code requires all applications to be processed simultaneously by the highest review authority. Therefore, the Planning Commission’s role in this matter is to forward a recommendation to the City Council for the four discretionary entitlements described below.
The following analysis sets forth the foundation for the Findings of Fact contained in the attached resolutions. Together, the analysis and findings provide the basis for staff’s recommendation that the Planning Commission recommend approval of the Project and all of its components, subject to the conditions set forth in the approval resolutions.
Vesting Tentative Tract Map (Diamond Bar Municipal Code Section 21.20.130) Pursuant to Section 66424 of the Subdivision Map Act, a Tentative Tract Map is required to establish separate residential and open space parcels, create an internal circulation system and common open space areas, and establish easements and other rights-of-way for utility and other purposes. A Vesting Tentative Tract Map confers a vested right to proceed with development in substantial compliance with the requirements in effect at the time the vesting tentative map was approved. In other words, a Vesting Tentative Tract Map locks in the rules and regulations in place at the time of approval.
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The subdivision of the project site creates separate development areas within the subject property that can be conveyed to subsequent holders of real property interests, as well as establish common open space areas. The seven, individually-owned residential lots proposed within the development will be governed by an HOA. The public street will be maintained by the City. The trailhead lot and open space/landscaped areas within the development will be part of the common areas to be owned and maintained by the HOA. The project will be subject to CC&Rs, which will be subject to review and approval by the City Attorney prior to the issuance of building permits and/or Final Map approval.
Subdivision Standards: The proposed subdivision is in compliance with the City’s Municipal Code standards pertaining to lot size and dimensions. The following table compares the proposed subdivision with the City’s subdivision standards:
Development
Feature
Development
Standards Proposed MeetsRequirements
Parcel Width Minimum 50’
Lot 1: 89.68’
Lot 2: 80’
Lot 3: 65’
Lot 4: 175.08’
Lot 5: 177.46’
Lot 6: 65’
Lot 7: 79.80’
Yes
Parcel Depth Minimum 80’
Lot 1: 93’
Lot 2: 130.49’
Lot 3: 130.49’
Lot 4: 103.54’
Lot 5: 93.15’
Lot 6: 160.64’
Lot 7: 241.43’
Yes
Lot Area Minimum 10,000
SF
Lot 1: 8,340 SF*
Lot 2: 10,439 SF
Lot 3: 8,482 SF*
Lot 4: 16,826 SF
Lot 5: 13,134 SF
Lot 6: 10,283 SF
Lot 7: 15,158 SF
Yes
* The RL-PD Overlay District allows modifications to minimum lot area. See CUP discussion below.
As part of the subdivision review, staff sent notices to all public utility companies and service agencies regarding the proposed subdivision. All agencies will be expected to provide service to the proposed parcels, including providers of gas, electrical, water, sewer, and cable telecommunication services.
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As set forth in the above analysis, the proposed subdivision is in conformance with the City’s General Plan and zoning, and all applicable requirements of the Subdivision Map Act. The subdivision complies with the City’s development standards and all public utilities and services will service the project.
Parkland Dedication
State law (“Quimby Act”) and Diamond Bar’s Subdivision Ordinance require the dedication of land or payment of fees for park or recreational purposes as a condition of approval for a tentative map. The land or fees are to be used only for the purpose of developing new or rehabilitating existing park or recreational facilities to serve the subdivision, and the amount and location of land to be dedicated, or amount of fees paid, shall bear a reasonable relationship to the use of the park and recreational facilities by the future inhabitants of the subdivision.
The amount of acreage required to be dedicated, or in-lieu fee paid, by the applicant is based upon the number of dwelling units ultimately developed within the proposed subdivision1. Section 21.32.040 of the Subdivision Ordinance establishes the following formula for the parkland dedication requirement:
X = .005(UP)
Where:
X = Amount of parkland required, in acres.
U = Total number of approved dwelling units in the subdivision (seven) P = 3.4 for single-family dwellings
The in-lieu fee equals the parkland obligation derived from the formula above, multiplied by the fair market value of the land for the appropriate park planning area of 0.119 acres. Staff used the most recent approved tentative parcel map to calculate the fair market value ($2,271,591 per acre) to acquire land for park space, or other per-acre “fair market value” determined by mutual agreement of the City and the applicant prior to approval of the final parcel map.
The in-lieu fee for this project is determined to be $270,3192 and shall be paid prior to the issuance of building permits for the construction of any residential structure(s) within the subdivision (see Condition of Approval #4 under Vesting Tentative Tract Map Conditions).
1 State law prohibits the City from applying the Quimby Act to ADUs. 2 $2,271,591 (fair market value of one acre parkland) x 0.119 = $270,319
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Development Review (DBMC Chapter 22.48)
The purpose of Development Review (DR) is to establish consistency with the General Plan through the promotion of high aesthetic and functional standards to complement and add to the economic, physical, and social character of the City. The process ensures that new development and intensification of existing development yields a pleasant living environment, and attracts the interest of residents and visitors as the result of consistent exemplary design.
Development Standards: The following table compares the proposed project with the City’s development standards for residential development in the RL-PD zone:
Development
Feature
Residential
Development
Standards
Lot 1 Lot 2 Lot 3 Lot 4 Lot 5 Lot 6 Lot 7 Meets
Reqs.
Front
Setback 20 feet 20 feet 20 feet 20 feet 14 feet* 13’-9”* 39’-5” 63’-6” Yes Side
Setbacks
10 feet on
one side,
5 feet on the
other
5’ - north
20’3”- south
24’ - north
5’ - south
10’ - north
5’- south
10’ - north
92’2” -south
99’4”- north
5’ - south
10’ - north
5’ -south
10’ - north
5’ - south Yes
Distance
Between
Adjoining
Structures
15 feet 30’ - north
N/A - south
35’ - north
15’ - south
15’ – north
15’ – south
15’ – north
182’ - south
182’ - north
15’ - south
15’ - north
15’ - south
15’ - north
N/A - south Yes
Rear Setback
20 feet from
edge of
descending
slope
20 feet 23’-10” 20’-8” 24’-9” 21’-3” 27’-3” 20 feet Yes Lot
Coverage
Maximum of
40% 23% 21% 26% 11% 14% 22% 16% Yes
Max.
Building
Height
35 feet 34’ 34’ 34’ 34’ 34’ 34’ 34’ Yes
Parking 2-car garage
3-car
garage
3-car
garage
3-car
garage
3-car
garage
3-car
garage
3-car
garage
3-car
garage
Yes
Retaining
Walls
4-foot exposed
(supporting fill)
6-foot exposed
(supporting
cut)
4 feet
(supporting
cut)
4 feet
(supporting
cut)
N/A
7 feet
(supporting
fill)*
10 feet
(supporting
fill)*
5 feet
(supporting
cut)
10 feet
(supporting
fill)*
8 feet
(supporting
cut)
10 feet
(supporting
fill)*
Yes
* The RL-PD Overlay District allows modifications to minimum setbacks and retaining walls. See CUP discussion below.
The project is comprised of seven single-family residences and complies with the development standards in the RL-PD zone with the exception of the modifications being requested. The Planned Development Overlay District allows for these modifications when deemed to be the best layout due to the constraints of the property.
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Site and Grading Configuration: The site grading was designed around geotechnical constraints of the site and to preserve the existing hillside to the extent feasible, given that any public roadway extension would require some degree of landform alteration.
The main access road curves to follow the contours of the hillside, thereby substantially reducing the retaining wall heights and avoiding potential biological impacts to the eastern portion of the site. The majority of the building pads are located on the western portion of the site that is generally flat.
The Project site shows evidence of historical landslides. The proposed onsite grading located immediately south of the existing single-family residence on the east side of the existing Crooked Creek Drive cul-de-sac would remove the soils susceptible to a landslide. After removal, the area would be re-stabilized with a combination of new soil and compaction. This landslide area is within proposed Lot 1. According to the geotechnical report, a portion of this landslide area underlying the pad areas were found to be dense/stiff, slightly compressible, competent, and is considered to be suitable for support of proposed structures.3 The Project is required to comply with applicable seismic-related regulatory requirements of Title 15, Building and Construction Safety, of the City’s Municipal Code and the latest standards of the California Building Code.
The current development proposal would require approximately 14,480 cubic yards of cut and 19,510 cubic yards of fill. 5,030 cubic yards will be imported to the site.
Fencing and Retaining Walls: The following diagrams provide details for the proposed property walls, retaining walls and fencing associated with the Project. 3 Geotechnical Report: Tract 54081, LGC Valley, Inc., August 31, 2020
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Cross section across Lot 5
Fence and wall plan
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Example of landscaped Verdura walls at the Willow Heights residential project at the southeast corner of Diamond Bar Blvd. and Brea Canyon Rd. · The rear yards of all residential lots adjacent to the Brea Canyon flood control channel will be bordered with wrought iron fencing up to 5’-6” in height. Six-foot high split-faced block walls will be constructed along the side yards of all residential lots. · On the eastern portion of the proposed expansion of Crooked Creek Drive, an exposed split-faced retaining wall with varying heights will be constructed. An 11-foot to 17-foot-high retaining wall is proposed from the southern portion of Lot 1 to approximately 120 feet south. Heights will range from six feet to 10 feet for the remaining portion of this retaining wall beyond 120 feet to the proposed cul-de-sac. · A 7-foot-high exposed retaining wall with a 42-inch-high wrought iron fence on top of the retaining wall is proposed at the south side of Lot 7 and adjacent to the Southern California Edison property. Top of retaining walls will be planted with climbing vines to help screen the height of walls.
· On the western portion of the development area adjacent to the Brea Canyon flood control channel, two approximately eight- to 10-foot-high Verdura retaining walls are proposed. Verdura walls are an interlocking, stackable, plantable wall system. In addition to the landscaping proposed in the Verdura walls, top of Verdura walls will be planted with trailing rosemary and bougainvillea to further screen the wall heights.
A condition of approval is included in the draft resolution that all retaining walls adjacent to the flood control channel and adjacent to the roadway will be maintained by the HOA.
All associated landscaping which are part of screening the walls will also be maintained by the HOA through an access easement.
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Architectural Features, Colors, and Materials: The City’s Design Guidelines have been established to encourage high-quality building and site designs that contribute positively to the visual quality of community through aesthetically pleasing site planning, building design, and architecture. In addition, a primary objective is to promote compatibility with adjacent uses to minimize any potential negative impacts.
Notable elements of the project design which address the Citywide Design Guidelines include, among other things, the following:
· Tuscan or Italianate-inspired architecture;
· Three floor plan versions with reversed layouts to provide variation and diversity to the building elevations;
· Articulation of facades and the massing of structures to give depth and substance to the building forms;
· Integration of varied texture, relief, and design accents on building walls to add finegrained visual interest to the architecture (e.g. stone veneer, stone trim and stone accents);
· Variation among the entry porches, window enhancements, and color palettes to create individuality between units;
· Recessed windows to provide depth to wall surfaces;
· Roof rafters, corbels, large eave overhangs and metalwork to be consistent with the traditional materials and details associated with the Tuscan/Italianate design language;
· Well-defined entrance roof elements supported by posts and colonnades; · Banding to break up the first and second floors; and
· Carriage-style garage doors.
Landscaping: A conceptual landscape plan was submitted with the application. The landscape design will enhance the development with a mix of evergreen and deciduous trees and shrubs. Brisbane box, Bradford pear and fruitless olive trees will be planted by the roadway and along the project perimeter. Native trees found in the area such as Rendering of proposed homes on Lots 3 and 4
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coast live oak and Southern California black walnut will also be used as open space plantings and within landscaped areas to tie in with the natural surroundings. These trees are proposed at the center of the Project site and within slope plantings which will provide for large scale canopy trees. Through the combination of decorative walls and paving, various tree species, an attractive drought-tolerant plant palette with a mix of ornamental and native plants, this well-planned landscape will create a unique sense of place that further enriches Diamond Bar’s urban forest.
The applicant is proposing a variety of trees to be planted throughout the Project site, including seven 36-inch box fruitless olive trees, twelve 24-inch box coast live oak trees, fifteen 15-gallon Brisbane box trees, eleven 15-gallon Bradford pear trees, and 201 5- gallon Southern California black walnut trees. Two non-protected trees will be removed due to their proximity to construction. The Tree Permit section provides further analysis on the removal, replacement and protection of existing protected trees. A row of Bradford pear and fruitless olive trees will be planted along the rear yards of Lots 2 through 7 to minimize the visual impact of the development to the adjacent homes across the flood control channel. A 15-foot-wide landscape easement in the rear yard of lots 2 through 4 and a 10-foot-wide landscape easement in the rear yard of lots 5 through 7 are proposed to ensure future homeowners do not remove these trees, which are strategically planted for screening purposes.
Additionally, various 5-gallon and 1-gallon shrubs that have a variety of color, texture, and form are proposed throughout the front, side and rear yards. Overall, landscaping consists of drought tolerant and non-invasive species to minimize irrigation and reduce the area of turf. The project is required to comply with the City’s Water Efficient Landscaping Ordinance, and compliance will be verified during building plan check and final inspections.
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Fuel Modification Plan
The subject property is located within the Los Angeles County Fire Department “Very High Fire Hazard Severity Zone.” Therefore, proposed landscaping must comply with the Fire Department’s Fuel Modification Plan requirements. Typically, landscape plans are submitted for review and approval by the Fire Department during building plan check. As of December 28, 2018, the Office of Planning and Research amended Appendix G of the CEQA Guidelines for agencies to identify and evaluate wildfire risks during the environmental review. Therefore, the applicant submitted the Fuel Modification Plan as well as the conceptual landscape plans to the Fire Department for preliminary review and received a preliminary approval on August 27, 2021.
Tree Permit (DBMC Section 22.38.110)
A Tree Permit is required when the removal or protection of a protected tree is requested. A protected tree is any of the following:
· Native oak, walnut, sycamore and willow trees with a diameter at breast height (DBH) of eight inches or greater;
· Trees of significant historical or value as designated by the City Council; Conceptual landscape plan
N
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· Any tree required to be preserved or relocated as a condition of approval for a discretionary permit;
· Any tree required to be planted as a condition of approval for a discretionary permit; and
· A stand of trees, the nature of which makes each tree dependent upon the others for survival.
The Development Code requires the preservation and maintenance of coast live oak and Southern California walnut trees with a DBH of eight inches or greater. When removal is allowed as a result of new development on residential sites larger than 20,000 square feet, replacement trees shall be planted at a 3:1 ratio.
The project requires the removal of two non-protected trees and 62 protected trees consisting of 58 Southern California black walnuts and four coast live oaks. The applicant is proposing to replace the protected trees with 201 Southern California black walnuts (27 more than the minimum replacement requirement) and 12 coast live oaks, totaling 213 replacement trees to be planted on-site. A mitigation measure outlined in the Mitigation Monitoring and Reporting Program (MMRP) requires the replacement trees to include a combination of boxed trees within landscaped areas, and seedlings and smaller-sized container trees in the undisturbed woodland areas of the Project site that is outside of the development area and fuel modification zones. The replacement coast live oak trees will be a minimum 24-inch box size, while 5-gallon Southern California black walnuts will be planted due to the scarcity of larger sizes of this tree species in local inventories.
Prior to the issuance of a grading permit, a protected tree replacement plan will be required, which will provide a methodology of soil preparation, planting, monitoring, survival percentages and a maintenance agreement stipulating the applicant’s obligations for a minimum three-year period, including the annual reporting, as well as corrective measures if survival percentages do not meet the replacement ratio.
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Conditional Use Permit (DBMC Section 22.58.040)
A conditional use permit is required for all development proposed on a site within a Planned Development (PD) Overlay District. Depending on site-specific constraints, the CUP may include modifications to the City's development standards, such as minimum lot area, setbacks, site coverage, floor area ratio, height limits, landscaping, or parking.
The PD Overlay District may be applied to areas where site characteristics and environmental resources, adjacent land uses, or other community conditions may be benefited by site-specific planning or the design of structures that would not otherwise be allowed in the primary zoning district. However, proposed development and new land uses within the PD Overlay District shall comply with all other applicable provisions of the Development Code. For this project, a CUP is required for modifications to:
· The retaining wall height limit to allow a maximum of 17 feet (where 6 feet is the code-prescribed height limit);
· Reduce the front setback for Lots 4 and 5 to 14 feet and 13’-9”, respectively (where 20 feet is the code-prescribed minimum); and
Tree removal and replacement plan
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· Reduce the minimum lot size for Lots 1 and 3 to 8,294 square feet and 8,482 square feet, respectively (where 10,000 square feet is the code-prescribed minimum).
The PD Overlay District allows for modifications from code-prescribed development standards when such modifications are warranted due to the unique topographical constraints and configuration of a development site. Staff finds that the proposed modifications to the development standards will facilitate the avoidance or substantial reduction in impacts to the surrounding ecological resources by reducing grading encroachments into the existing hillside, as well as protecting the privacy of the existing homes located adjacent to the flood control channel. Without the proposed modifications to the code-prescribed development standards, more retaining walls and grading would be required to create the building pads and roadway improvements for the proposed development.
Compliance with Hillside Management Ordinance (DBMC Section 22.22) The proposed project was reviewed for compliance with the City’s Hillside Management Design Guidelines and regulations. The project complies with all of the regulations and guidelines to ensure that development will complement the character and topography of hillside areas set forth in the Development Code. The project site was designed to conform to the following requirements:
· The maximum building height is 34 feet, where 35 feet is allowed. · Architectural treatment is provided on all sides of the building with varying setbacks and projections;
· Earthtone building materials and color schemes that blend in with the natural landscape are proposed;
· Finished slopes are not greater than 50 percent (2:1); and · Landscaping will be used to preserve privacy, and slopes will be planted with informal clusters of trees and shrubs to soften and vary the slope planes.
Screening of the Verdura walls will be accomplished by installing individuallyirrigated plants within the cells of the walls, and by planting trailing rosemary and bougainvillea at the top of the walls.
The project complies with all of the regulations and guidelines to ensure that development will complement the character and topography of hillside areas set forth in the Development Code.
Community Meetings
As discussed in the Background section of this report, the developer held two community meetings for this project: on February 22, 2018 and October 10, 2019.
Notices for those meetings were mailed to property owners within a 1,000-foot radius of the Project site.
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First Meeting on February 22, 2018
There were approximately 14 residents in attendance. The preliminary project redesign presented at the meeting proposed a 12-lot subdivision. The retaining walls on the western portion of the project area (i.e., the Brea Canyon Flood Control Channel side) proposed two retaining walls with a 24-foot average height. On the eastern portion of the project area (i.e., the hillside), five tiered retaining walls were proposed with a 60- foot average height, with a 2:1 slope cut into the hillside above the top retaining wall.
This proposal anticipated a total of 90,000 cubic yards of cut and 52,000 cubic yards of fill. Several concerns and comments were raised, which are listed below with responses provided in italics:
· Wall heights are of concern. Will the walls be landscaped and will proper drainage be installed?
The number of retaining walls and wall heights have been reduced in the current proposal. Top of retaining walls will be planted with climbing vines to help screen the height of walls. In addition to the landscaping proposed on the Verdura walls, top of Verdura walls will be planted with trailing rosemary and bougainvillea to further screen the walls.
· How is the project going to handle landslides that may be caused by an earthquake? The City requires that all new construction meet or exceed Title 15, Building and Construction Safety, of the City’s Municipal Code, and the latest standards of the California Building Code (CBC), which requires structural designs that can accommodate seismic-related ground shaking, soil stability and hazard impacts.
Furthermore, the geotechnical report provides preliminary site-specific design recommendations and parameters regarding grading and earthwork, temporary excavations, drainage, foundations, retaining walls, and pavement design. As a standard condition of approval, the Project will be required to comply with the recommendations of the geotechnical report.
· Where is the access to the open space and who will maintain it for fire hazards? Access is provided within an easement north of Lot 1. Ongoing maintenance for vegetation control as mandated by the L.A. County Fire Department will be required of the HOA.
· What will be given back to the neighborhood such as trails and/or parks? Lot A will be reserved for the trailhead, which will be maintained by the HOA. At such time that the L.A. County Department of Parks and Recreation establishes a connection to the Schabarum Trail, the HOA will be required to remove the fencing and the trailhead lot transferred to the City. In addition, Quimby fees will be paid to improve City park and recreational facilities. (See Parkland Dedication discussion above.)
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· How much vegetation will be removed and how much mitigation is proposed? One resident stated that they would like to see the benefit of mitigation on-site, and the need for a clear mitigation plan. It does not make economic sense with the HOA maintaining all of the open space. Can the open space be donated to a conservation group?
See Tree Permit section above. The applicant is open to further discussions with interested parties regarding the open space lot being donated to a conservation group.
· The community would like to see visual simulations. Will the homes be higher? Will there be a change in elevation between the old and new development? Visual simulations were provided with the most recent proposal. The building pad of Lot 1 will be level with the adjacent residence. The building pad of Lot 2 is ten feet lower than that of the adjacent residence. The building pads of Lots 2 through 7 will be approximately five feet higher than the homes located on Castle Rock Road, across the flood control channel.
Second Meeting on October 10, 2019
There were approximately 11 residents in attendance. The applicant team presented a design with an 11-lot subdivision and narrowed width of Crooked Creek Drive to further reduce retaining wall heights. Wall heights were reduced from a 60-foot average to a 30-foot average on the eastern portion of the project area (i.e., the hillside), and lowered the retaining wall heights adjacent to the flood control channel from a 24-foot average to a 12-foot average. Lastly, split-level building pads that step down toward the channel were introduced to reduce grading and visual impacts. The applicant team also presented visual simulations of the streetscape and views of the proposed homes from across the flood control channel. Although the attendees expressed appreciation of how the project was redesigned to reduce impacts, there were still similar concerns and comments raised at the first meeting. Other concerns raised at the second meeting include the following (with responses in italics below):
· Private street concerns regarding emergency access, vehicle code enforcement, and if it will be gated.
A private street is no longer being proposed and the street will be public, maintained by the City.
· Slope and retaining wall concerns regarding soil stability and amount of grading required.
See response above regarding landslides and minimum Code requirements for retaining walls. The current proposal would require approximately 14,480 cubic yards of cut and 19,510 cubic yards of fill. 5,030 cubic yards will be imported to the site.
· Ensure invasive species are not introduced to the area.
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All landscaping will be drought tolerant and non-invasive species to minimize irrigation and reduce the area of turf. Native trees such as coast live oak and Southern California black walnut will be planted in open space and other landscaped areas.
· There are important wildlife resources, such as California gnatcatchers and nests found in the area.
Refer to IS/MND Biological Resources section and mitigation measures. · Concerns with construction impacts to neighboring residents.
All construction activity shall comply with the City's Municipal Code. Construction hours will be restricted to between 7:00 A.M. and 7:00 P.M, Monday through Saturday, except on federal holidays. Since daylight ends earlier during the winter, no construction activities shall occur after 5:00 P.M. during this time. Additionally, three mitigation measures are required to reduce the level of noise generated from the project to a less than significant level.
· What are the view impacts from other areas in the neighborhood and not just from across the flood control channel?
Visual simulations were provided with the most recent proposal which includes viewpoints from the SR-57 freeway, Brea Canyon Road, Castle Rock Road and at the project entry. The visual simulations can be found in the architectural plan set (sheets IMG-1 through IMG-8).
Lastly, the applicant personally met with two individuals representing two advocacy groups on June 22, 2021: Sierra Club and Responsible Land Use. The applicant discussed the history of the project, presented all versions of the previous designs and the challenges associated with them. The applicant explained that all of the modifications to the site plan including the redesign of the street that curves away from the hillside and the reduction of lots were made with the express purpose of reducing overall grading impacts, minimizing retaining wall heights and reducing impacts to native habitat and trees. According to the applicant, the representatives were appreciative of these efforts to redesign the project to be more sensitive to the surrounding environment with a more thoughtful, less impactful design. Sierra Club and Responsible Land Use requested involvement during the final landscape and irrigation design for the project, including the planting and irrigation of the replacement native oaks and walnut replacement trees. The applicant agreed to involve them during this process. The representatives also offered to assist the applicant with finding an entity that would potentially be interested in taking ownership of the remainder open space parcel, which the applicant will continue to analyze and keep city staff apprised.
Compatibility with Neighborhood
The proposed project complies with the goals, objectives and land use criteria as set forth in the adopted General Plan in terms of land use. The design and appearance of the proposed residential development is compatible with the surrounding community and incorporates the principles of the City’s Residential Design Guidelines as follows:
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· Quality Housing. The project contributes to the diversity of the City’s housing stock with high-quality housing and the added bonus of an ADU to accommodate persons of all ages, occupations and levels of financial status. · Architectural Design. The project has varied architectural building details, finishes and design accents on the elevations, and there is diversity between the units from street view. Facades are articulated with varying setbacks, projections, and varied textures, which mitigates the scale and massing of the structures. · Preservation of Existing Hillside. The Project is designed to minimize negative impacts to the existing hillside. The main access road curves away from the hillside to follow the natural contours, thereby substantially reducing the retaining wall heights and minimize potential aesthetic and biological impacts to the eastern portion of the site.
· Compatibility with Adjacent Uses. Although the proposed homes will be larger in size compared to the existing homes on Crooked Creek Drive, the project is designed to minimize negative impacts on surrounding uses. There is a gradual transition between the project through appropriate setbacks, building height, landscaping, and window and door placement.
Homes on Lots 1 and 2 were carefully designed to minimize potential privacy impacts to the existing adjacent homes on Crooked Creek Drive. The home on Lot 1 will be distanced 30 feet away from the adjacent home and 40 feet from proposed third story windows. The alignment of the proposed home would not impact the rear yard of the existing home. Views would only face the side elevation of the existing home which have no windows or to the front yard which is already visible from the street. The building pad of Lot 2 will be approximately 10 feet lower than the building pad of the adjacent home, thereby reducing the overall height, and the new home will maintain a 35-foot distance from this neighbor. Additionally, there are existing mature trees that exist on the adjacent property that provides a dense buffer.
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Rendering of proposed home on Lot 1 and adjacent existing home located on 3722 Crooked Creek Drive
Aerial view of proposed Lots 1 and 2 and
adjacent neighbors on Crooked Creek Drive
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Rendering of view from Castle Rock Road looking east
A row of Bradford pear and fruitless olive trees will be planted along the rear yards of Lots 2 through 7 to not only minimize the visual impact of the development, but to maintain privacy for the existing and future residents. With the proposed landscape easement in the rear yards of these residential lots, a landscaping buffer will be maintained in order to provide some visual relief to existing homes.
The development is designed to minimize visual impacts to the surrounding homes by use of landscape screening and gradual transitions of the slope plane with terraced Verdura walls.
Native trees found in the area such as coast live oak and Southern California black walnut will be used as open space plantings and within landscaped areas which are compatible and harmonious with the prevailing pattern of planting in the immediate area. Other various tree species will be used to soften building lines and Rendering of proposed home on Lot 2 and adjacent existing home located on 3723 Crooked Creek Drive
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blend structures with the environment, creating a transition between the hard vertical edges of buildings and walls and the softer horizontal lines of the site. · Landscape Design: Effective landscape design should serve the dual purpose of intrinsically enhancing a project setting, as well as integrating the landscaping into the overall architectural design. Staff finds the proposed plant palette to be diverse, and the plant selections are compatible with Southern California native landscapes.
Additional Review
The Parks and Recreation and Public Works/Engineering Departments, Building and Safety Division, as well as the County of Los Angeles Fire Department reviewed this project and included their comments in the attached resolution as conditions of approval (Attachment B).
Public Comments Received
No comments have been received as of the publication date of this report, except those received during the public review period of the IS/MND.
ENVIRONMENTAL ASSESSMENT:
This Project has been reviewed for compliance with the California Environmental Quality Act (CEQA). Based on that assessment, the City prepared an Initial Study and filed a Notice of Intent to Adopt a Mitigated Negative Declaration (MND) for the Project with the Office of Planning and Research on November 9, 2021, and with the Los Angeles County Clerk on November 10, 2021. The notice was published in the San Gabriel Valley Tribune newspaper (see Exhibit A of Attachment A). The notice was also mailed to public agencies and residents who attended the community meetings.
Pursuant to CEQA Section 15105, the public review period for the IS/MND began on November 10, 2021, and ended on December 20, 2021, for a total of 40 days.
The Initial Study is an environmental analysis that is prepared to determine whether a Negative Declaration, Mitigated Negative Declaration, or Environmental Impact Report (EIR) is needed for a project. If the Initial Study concludes that the proposed Project will not significantly affect the environment, a Negative Declaration may be prepared. If there are potential impacts from the proposed Project that can be mitigated to a level below accepted levels of significance, a Mitigated Negative Declaration may be prepared. The Initial Study concluded that the Project will not significantly affect the environment through the incorporation of 22 mitigation measures, and as the result of revisions made to the Project design from previous versions.
An MND is a document that describes the reasons that the Project will not have a significant effect on the environment by properly conditioning the Project (“mitigation measures”) to make the Project acceptable. It is used to guide and assist the City staff,
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Planning Commission, City Council, and the public in the consideration and evaluation of potential environmental impacts that may result from the Project and must be considered by the Commission prior to recommending approval of the Project.
The MND for the Project, documents reasons to support the findings that the Project would not have any potentially significant impacts on the environment with the proposed mitigation measures which are contained with the Mitigation Monitoring and Reporting Program (MMRP) prepared as part of the MND. The purpose of the MMRP is to ensure compliance with the mitigation measures, address site-specific conditions for the Project, and also identifies timing and responsibility for monitoring each measure. The Project is conditioned to include these mitigation measures as part of Project approval.
During the public review period, the City received seven comments on the draft IS/MND from the following agencies/groups:
1. California Department of Fish and Wildlife (CDFW): Various impacts on fish and wildlife (biological) resources and additional mitigation measures advised to adequately address potential impacts.
2. County of L.A. Department of Parks and Recreation: Public access easement to trailhead and future County trail.
3. County of L.A. Fire Department: Access and water requirements. Impacts to erosion control, watershed management, rare and endangered species, vegetation, fuel modification, archaeological and cultural resources, and the County Oak Tree Ordinance.
4. Diamond Bar - Pomona Valley Sierra Club Task Force: Biological resources, air quality, hydrology, fuel modification, wildfire, trail access and concurrence with CDFW’s additional mitigation measures.
5. L.A. County Sanitation Districts: Wastewater requirements.
6. Responsible Land Use: Concurrence with CDFW’s additional mitigation measures.
7. Sierra Club Wildland Urban Wildfire Committee: Wildfire impacts.
Responses to each of the comments received were prepared and posted on the City’s website at www.diamondbarca.gov/crookedcreeksubdivision. The agencies/groups that commented were individually notified of the availability of the response to comments along with the public hearing notice on April 15, 2022.
NOTICE OF PUBLIC HEARING:
On April 15, 2022, public hearing notices were mailed to property owners within a 1,000-foot radius of the project site, as well as to the public agencies that commented on the IS/MND and residents who attended the community meeting. On April 15, 2022, the notice was published in the San Gabriel Valley Tribune newspaper. A notice display board was posted at the site, and a copy of the notice was posted at the City's designated community posting sites.
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PREPARED BY:
REVIEWED BY:
Attachments:
A. Draft Resolution No. 2022-XX (Recommending Approval of MND and MMRP) B. Draft Resolution No. 2022-XX (Recommending Approval of VTTM, DR, TP, and CUP) and Standard Conditions of Approval
C. Site Utilization Map, Vesting Tentative Tract Map, Conceptual Grading Plans, Architectural Plans, and Landscape Plans
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