Staff Report

ITEM NO.   2

MEETING DATE: 10/11/00

PROJECT DATA

Address: South (upslope) side of Trestle Glen Boulevard west of its intersection with Turtle Rock Court (PD#18B)

AP No.: 58-061-80 & 86

File No.: 39903

General Plan: L (Low Density Residential (up to 0.3 du./acre)

Zoning: RPD (Residential Planned Development Zone - up to 0.3 du./acre)

Property Size: 13.25 acres

Subdivision: PM 10-8 (1974)

Current Use: Undeveloped land

Owner: Round-Two Development Joint Venture

Applicant: Don Henderson & Craig Pilgrim

Date Complete: August 20, 1999

SITE HISTORY

The property was once part of the greater holdings of the Little Reed Ranch owned by the heirs of John Reed. It was later part of the Bostick Brothers Dairy operation as cattle grazing land. In 1949 (predating Belveron Gardens Subdivision), the Bostics received Tentative Subdivision Map approval from the Marin County Supervisors for Hacienda Terrace, a 50-lot subdivision involving this and adjacent property to the east. About 32 single-family lots would have been located on the current Tiburon Court project site. Only the Benton Court and Warren Court portions of Hacienda Terrace, comprising 18 lots, proceeded to the Final Subdivision Map stage and were developed.

In 1973, a 54-unit townhouse project called Tiburon Towne was submitted for approval on this site and on the adjoining Lower Trestle Glen property, which were under the same ownership at that time. Approximately 42 of the 54 townhouse units would have been built on the Tiburon Court portion of the site. The maximum density at the time was up to 2.5 units per acre, allowing up to 69 units on the 28-acre total site. That application was withdrawn in October 1974 for unspecified reasons.

In 1978, the property was conveyed to Cherry family, which owned it into the 1990’s. In July 1981, the owners filed a proposal for a 36-unit single family lot project called Tiburon Meadows. Approximately 13 of the 36 units would have been located on the "Tiburon Court" portion of the 28 acres. The property was still zoned for up to 69 units at that time. This proposal was eventually withdrawn due to a lack of funding by the applicant to further process the application.

In 1989, the Town of Tiburon revised its General Plan and "down-zoned" the entire property from a density of 2.5 units per acre to 0.3 units per acre, allowing a maximum of 8 lots on the 28-acre Cherry Property. In the mid-1990s the two major holdings comprising the Cherry property were sold to different buyers. The current development application (Exhibit 1) for four homes was filed in 1999.

PROJECT DESCRIPTION

The Tiburon Court project would create four residential lots ranging in size from 2.36 to 5.03 acres (an average of approximately 3.3 acres per lot) on the 13.25-acre site). Each lot would be developed with one single-family detached unit and accessory uses. Drawings of the proposed project are attached as Attachment A (large-scale) and Attachment B (11" X 17" reduced).

Residential Building Envelopes Plans identify residential building envelopes, secondary recreational envelopes, and private open space. Residential building envelopes would range from 0.19- to 0.81-acre, and each would be developed with a split-level 4,800-square foot unit with a 3,000-square foot footprint. The maximum height of units on Lots 1, 2, and 3 is proposed to be to 30 feet and on Lot 4 is 35 feet. Residential building envelopes on Lots 1 and 2 designate areas from approximately the 160- to 170-foot contour uphill to the 190-foot contour where maximum building heights would be limited to 18 feet above the finished grade. Proposed units are intended to be similar in size and appearance to homes in the Turtle Rock Court subdivision. 

Source: Tiburon Court Precise Development Plan Site Plan, Grading & Drainage Plan, Lawrence P. Doyle, Land Surveyor / Civil Engineer, July 12, 1999.

a only includes residential building envelope and excludes secondary recreational envelope.

b Shows percent of total lot area devoted to building envelope area where residential development could occur.

c Areas do not add to 13.25 acres (577,231 square feet) given on application materials.

 

Lots 1 and 2 would be upslope lots and Lots 3 and 4 downslope lots. Average slopes would be 29.5 percent (Lot 1), 28.6 percent (Lot 2), 18.2 percent (Lot 3), and 27.4 percent (Lot 4).

Secondary Recreational Envelopes A secondary recreational envelope is proposed on Lot 3. Secondary envelopes originally proposed on Lots 2 and 4 have been deleted. The remaining secondary envelope on Lot 3 could be developed with a private tennis court or other ancillary uses not including out-buildings.

Private Open Space Land outside the residential building and secondary recreational lot development areas would be designated private open space, maintained by individual lot owners, and covered by a scenic easement. A ten-foot wide public trail easement is proposed across parts of proposed Lots 1 and 2 from Trestle Glen Boulevard (northeast corner of the site) to Porto Marino Drive (southeast corner). No other public recreational or other facilities are proposed. A varying width drainage easement along the incised drainageway would cross Lots 2, 3, and 4 in the southeast to northwest direction. In addition, the project would offer a ten-foot widening strip along Trestle Glen Boulevard for dedication to the Town.

A schematic Landscape Plan has been prepared which indicates tree and shrub types and sizes to be planted along the proposed access roadway and illustrates potential planting concepts for lots. Landscaping is estimated to cover approximately 10,000 square feet per lot.

Access Access would be via a 24-foot wide private roadway. It would intersect Trestle Glen Boulevard midway between Turtle Rock Court (east) and Juno Road (west) and would extend 250 feet south to a 60-foot diameter cul-de-sac bulb. The access roadway would be built across the private lots, and easements would be established to permit access by the other lot owners. Lot owners would be responsible for maintaining the roadway under a "common Driveway Maintenance Agreement" to be recorded after Town of Tiburon review and approval.

Infrastructure On- and off-site infrastructure improvements (roadway, including curbs and gutters, and utilities, including sewer, water, and drainage facilities) would be constructed for the entire project at one time. These include:

· Grading and construction of the site access roadway. Cutting would occur on the east side of the proposed alignment and would involve an estimated 3,500 cubic yards of material. Filling would occur on the west side of the roadway and would involve placement of 3,500 cubic yards of material, for a balanced grading operation.

· Construction of a 24-inch storm drain on the south side of Trestle Glen Boulevard. It would divert stormwater west and then north under the roadway to an existing concrete drainage canal in the Belveron subdivision west of Juno Road (and away from the existing box culvert under Trestle Glen Boulevard to an open drainage ditch east of Juno Road).

· Repair of landslides, including three within the drainage easement (Landslides 2, 3, and 4), one adjacent to trestle Glen Boulevard (Landslide 1), and the head areas of debris flow swales. Landslides 1 through 4 would be stabilized by excavating the slide, continuing the excavation through the slide plane to firm soil and / or rock below the slide plane, backfilling with engineered fill to desired grades, and concurrently installing subsurface drains. Head areas of debris flow swales would be regraded, and debris flow-susceptible material would be recompacted.

Project Site Setting The Tiburon Court project is proposed on part of a site formerly known as the Cherry property.  It is a vacant infill parcel located on the south side of Trestle Glen Boulevard and is surrounded by existing residential neighborhoods. Site elevations range from about 60 feet at Trestle Glen Boulevard in the northwest corner to 260 feet at the southeast property line with the Marin Convalescent and Rehabilitation Hospital on Hacienda Drive.

Two drainageways cross the site. The primary drainage originates at the end of Porto Marino Drive which stubs out at the southeast corner of the site. The drainage extends downhill in a northwest direction to an existing box culvert under Trestle Glen Boulevard located east of the Juno Road intersection. The second drainage originates on the adjacent "Trestle Glen Lower" parcel and flows north toward Trestle Glen Boulevard across the western end of the Tiburon Court project site. Both are intermittent streams. Site vegetation is composed of grasslands, scrub and bushfield, woodland, riparian scrub, and freshwater marsh.

Surrounding Land Uses Surrounding uses are residential, except for the undeveloped "Trestle Glen Lower" parcel located west of the site and the Marin Convalescent and Rehabilitation Hospital contiguous to the southeast corner of the site.

The Belveron Gardens East and Preserve (Turtle Rock Court) subdivisions are located north across Trestle Glen Boulevard and are designated for development at medium high (up to 4.4 units per acre) and medium low (up to 1.1 units per acre) densities, respectively. Residential areas south, east, and west of the site are designated for medium density (up to 3.0 units per acre) along Stewart Drive (south), medium high density on Benton Court (east), and both low density (0.3 unit per acre) on "Trestle Glen Lower" (west) and medium high density (Trestle Glen Terrace, west of Trestle Glen Lower). The Marin Convalescent and Rehabilitation Hospital, located on Hacienda Drive east of the site, is the only non-residential use in the vicinity. Except for the project site and "Trestle Glen Lower" parcel, the surrounding residential neighborhoods are virtually built out.

The Town of Tiburon is a predominantly residential community composed of established neighborhoods interspersed with permanent open space, including the nearby Ring Mountain Preserve. Tiburon Boulevard provides primary access along the Tiburon Peninsula between downtown Tiburon at the tip (southeast) and Highway 101 (northwest), the major transportation corridor which connects Marin County with the region. Trestle Glen Boulevard traverses the Tiburon Peninsula and provides the only cross-peninsula paved roadway connection between Paradise Drive (east) and Tiburon Boulevard (west).

ENVIRONMENTAL REVIEW

An expanded Initial Study and draft Mitigated Negative Declaration for this project was prepared under contract to the Town of Tiburon by the consulting firm of Nichols-Berman, and released for public review and comment on September 1, 2000. Planning Commissioners have previously received copies. An additional copy of the Initial Study is attached with Commission packets for convenience (Attachment C).

The initial study synthesized the findings of numerous professionally-prepared studies, an independent geotechnical peer review commissioned by the Town of Tiburon, and in-house peer review by the Town’s environmental consultant. The studies included a cultural resources study, traffic study, preliminary geotechnical engineering investigation and independent peer review, a faunal assessment, three biological studies, an acoustical analysis, a hydrology report, and a visual simulation. These documents are available for review in the Tiburon Planning Department.

The comment period on the draft Mitigated Negative Declaration closed on October 2, 2000 but is customarily extended to include the first Planning Commission public hearing. The draft mitigated negative declaration identifies several environmental factors that would potentially be affected by the project. These are:

Aesthetics

Air Quality

Biological Resources

Cultural Resources

Geology and Soils

Hazards and Hazardous Materials

Hydrology & Water Quality

Land Use & Planning

Noise

Recreation

Transportation and Traffic

Utilities & Service Systems

Mitigation measures presented in the Initial Study and accepted in writing by the applicant would reduce all potential impacts to less than significant levels. A brief discussion of each affected environmental factor is provided below.

Aesthetics

From a CEQA standpoint, the project would change but not substantially degrade the visual character of the natural hillside. The remaining secondary building envelope on Lot 3 would need to be defined to eliminate outbuildings to mitigate potential impacts.

Air Quality

Standard mitigation measures are proposed to reduce the potential dust and other air quality impacts that may occur during construction on the site. Measures include watering and sweeping of the site and streets, covering of materials, and hydroseeding of disturbed areas.

Biological Resources

Biological resources constitute the most limiting factor for development of the site from a CEQA standpoint. The entire portion of the property south of the intermittent stream must be avoided to prevent significant adverse impacts on biological resources. Secondary building envelopes originally proposed for this area have been eliminated. There are no significant biological resources on the portions of the site proposed for development. Significant biological resources on undeveloped portions of the site would be protected by a Town-held open space easement. These resources include riparian habitat, native grasslands, potential red-legged frog habitat, and oak woodland.

Cultural Resources

While it is very unlikely to occur, any discovery of subsurface cultural resources will result in a halt of the project work in the vicinity so that the proper authorities can be consulted.

Geology and Soils

As is common with hillside properties on the Tiburon Peninsula, the subject property contains areas of unstable soils in the form of landslides and debris flows. Debris flows and landslides are differentiated by the velocity at which the ground movement occurs. Debris flows are fast moving, highly fluid landslides that occur during periods of intense rainfall (i. e. mudslides). Landslides can move at a rate of only inches per day. Soils conditions on the site could also lead to settlement of structures, erosion, expansive soils, and long-term slope stability.

A preliminary geotechnical investigation was prepared for the project site as detailed in the Initial Study. This report was intensively reviewed by an independent geotechnical engineer retained by the Town of Tiburon, namely Eugene Miller of Miller Pacific Engineering, as well as by the Town Engineer.

Because soils on much of the Tiburon Peninsula are prone to instability, the Town of Tiburon has adopted stringent landslide repair policies (Exhibit 2). Landslide repairs and debris flow mitigations will be required as part of any subdivision of this property prior to the construction of individual homes. Completion of these improvements is fully bonded such that the Town can complete the work should the developer be unable to do so.

The Project Geotechnical Engineer, Town Engineer, and Town Geotechnical Consultant will ensure that the Town’s landslide repair policies are implemented on this property, eliminating or greatly reducing the potential for damage from soil instability. In comparison with the adjacent Lower Trestle Glen project site, unstable areas on the Tiburon Court site are small and completely avoid roadways and building envelopes. Except for an area of recent (1960’s) fill, the slide areas involve slumped areas along the side of the intermittent stream channel.

Hazards & Hazardous Materials

Susceptibility to wildland fires was identified as a potential project impact. Conformance with required provisions of the current Tiburon Fire Protection District codes will reduce potential wildland fire hazard impacts to less than significant levels.

Hydrology & Water Quality

Unlike the Lower Trestle Glen project site, the Tiburon Court site drains into off-site portions of the drainage system that were not upgraded in 1987-1988 by the developers of the Preserve Subdivision to serve the ultimate buildout of the Belveron Watershed. The inadequate drainage sections include an undersized 24" corrugated metal pipe located at the uphill side of Juno Road crossing and a degraded open drainage ditch upstream from the Juno Road crossing. At the downstream side of the Juno Road crossing, the upgraded culvert is 54" in diameter and both it and the 5 foot by 5 foot concrete box culvert downstream from the Juno Road crossing are sized and designed to accommodate buildout of the Belveron Watershed for the 100-year storm event.

The project proposes to divert a substantial portion of the site’s runoff around the undersized ditch and culvert and directly into the adequately sized box culvert below the Juno Road crossing. This measure would slightly reduce the amount of runoff entering the undersized drainage facilities upstream from the Juno Road crossing. An alternative solution (favored by the Town Engineer) would be to upgrade the 24" pipe under Juno Road crossing and improve the degraded ditch upstream from it, without any diversion. Given the fact that both Trestle Glen projects will be required to pay drainage improvement fees to the Town (or construct the actual improvements), either alternative will result in an improved drainage system and decreased risk of flooding for the Belveron Gardens Subdivision.

Noise

Potential short-term noise impacts from earthmoving, grading and paving machines were identified and mitigations proposed. Short-term construction impacts will inevitably cause irritation and inconvenience for surrounding properties. Such impacts, while certainly annoying, do not constitute significant adverse environmental impacts under CEQA. Limited hours for construction and use of heavy equipment will reduce noise impacts to less than significant levels, especially during traditionally quiet hours and on weekends.

Recreation

The project offers opportunities to expand the non-street portion of the Tiburon Ridge Trail by connecting across the site to Porto Marino Drive. The project sponsor shall design, build, and dedicate this trail to the Town of Tiburon.

Transportation and Traffic

Adequacy of intersection sight distances and adequacy of project parking were identified as potential impacts.

Vehicular access to the project would be from a single private roadway off Trestle Glen Boulevard, located along the frontage approximately 270 feet west of the Turtle Rock Court intersection and approximately 780 feet east of the Juno Road intersection with Trestle Glen Boulevard. Legal vehicular access to the property is only available from Trestle Glen Boulevard. The proposed private roadway location offers excellent sight distance (620 feet) to the west but marginal sight distance (295 feet) to the east due to the contours of the land immediately east of the proposed intersection. Mitigation measures are specified that will result in safe sight distances in both directions.

Parking mitigations will require five on-site spaces for each home plus the four on-street spaces on the private roadway. Special provisions for valet parking or shuttle service shall be incorporated into the CC&R's to address occasional special event parking situations.

The project will be required to pay its pro-rata share of traffic impact fees to address cumulative traffic generation impacts.

Utilities & Service Systems

Installation of a new sewer line along Trestle Glen Boulevard will be required. Alternatively, upgrading of the existing sewer line in Juno Road could be performed to serve the site. Either alternative will mitigate potential impacts, although the applicant prefers construction of a new sewer line to minimize the disruption within Belveron Gardens.

Public and agency comment letters have been received as follows:

Letter from Tiburon Ridge Association dated 12/28/99.

Letter from Town Engineer dated 8/21/00.

Letter from State Department of Fish & Game dated 9/12/00.

Letter from Frank Mullberg, 66 Hacienda Drive, dated 9/14/2000.

Letter from Michael & Sheila Lagios dated 9/26/00.

Letter from Anthony & Pamela Harrington dated 9/27/00.

Letter from Shaun & Janet Coughlin dated 9/28/00.

Letter from Randy Greenberg dated 10/2/00.

Letter from Barry & Rosalind Jekowsky dated 10/2/00.

Letter from Governor’s Office of Planning & Research dated 10/2/00.

Letter from U.S. Fish & Wildlife Service dated 9/20/00.

These letters are attached as Exhibits 3 through 13. The applicant, staff and consultants will be prepared to address these comments at the meeting. The applicant has offered to meet with any commentors subsequent to the meeting.

Zoning Ordinance Conformance

Section 4.08.04 of the Tiburon Zoning Ordinance sets forth the following principles to be evaluated in the review of Precise Development Plan applications. A summary of this project’s conformance with these principles is as follows:

(a) Significant open space shall be preserved, through dedication or other means acceptable to the Town, consistent with policies of the Open Space and Conservation Element of the Tiburon General Plan.

The project would leave approximately 80% of the site in a permanent open condition, including the oak trees, the intermittent stream channel, and riparian areas. The proposed precise plan indicates that, with the exception of a public pedestrian easement across the property, the open space would remain private. Developments of this nature typically confer "open space easements" to the Town over portions of the privately owned lots located outside the building envelopes. Staff does not recommend fee dedication of land in instances such as this project, where the remaining open space is isolated from other dedicated open space areas.

(b) Preservation of natural features of the land shall be achieved to the maximum extent feasible through minimization of grading and sensitive site design. Features worthy of preservation include ridgelines, prominent knolls, desirable native vegetation, trees, significant rock outcroppings, water courses, and riparian corridors.

Biological and habitat constraints limit development to the north side of the watercourse in order to avoid significant adverse impacts on the environment. The applicant has already agreed to eliminate the proposed secondary recreational envelopes on Lots 2 and 4 that were proposed for the south side of the watercourse. There will be no structures or improvements of any kind on the south side of the watercourse.

(c) Slopes created by grading should not exceed 30 percent. Final contours and slopes should reflect natural land features.

Most of the earthmoving activities would involve the removal of landslide and debris flow material, and recompaction of these same areas into stable slopes. Cutting and filling for the project roadway and individual homes will also occur. Final graded slopes shall not exceed 30% and shall resemble natural terrain.

(d) Every reasonable effort shall be made to preserve view corridors, mature trees, rare plants, significant native flora and fauna, areas of historical significance, access corridors, and habitats of endangered species.

Story poles have been erected by the applicant at the approximate locations of the homes to be built on each of the four proposed lots. A story pole and staking plan is attached as Attachment D. The poles have been in place since August.

(e) Location of development well below ridgelines shall be achieved, in accordance with General Plan and other policies.

Secondary Ridgeline #3 as identified in Resolution No. 2859 is the nearest ridgeline to the site, but is off the property. The project would have no effect on ridgelines.

(f) Prominence of development and construction should be minimized by appropriate location of grading and placing of buildings so that they are screened by wooded areas, rock outcroppings and depressions in topography or other features.

The property’s open hillside nature limits the ability to "hide" proposed homes using site features. Prominent trees on the site are located at the upper reaches that are inappropriate for development. Depressions in topography on this site are typically drainageways that should be avoided. On properties such as this, appropriate design of homes (in terms of height, size, mass, bulk, color, shape, architecture, landscaping and materials) is the best tool to achieve compatible construction that blends to the extent possible with the surroundings. "Show-me" homes and "monster" homes should be avoided on such sites.

(g) Due consideration shall be given to avoidance of areas posing geological hazards.

The geologically unstable areas of this site have been identified and discussed in the Initial Study. They will be repaired in accordance with the Town’s policies. Proposed homes and roadways avoid these unstable areas.

(h) Minimization of significant adverse impacts, as detailed in the Environmental Impact Report, if one is required.

A Draft Mitigated Negative Declaration and expanded Initial Study concluded that all potential adverse impacts to the physical environment, as defined by CEQA, are reduced to less than significant levels by mitigation measures incorporated into the project. Please refer to the Initial Study for details.

(i) Roads shall be designed for minimum slopes, grading, cut-backs and fill. Narrowing of roadways may be allowed to reduce grading, retaining walls, and other scarring of the land.

The 24 foot wide, 250 foot long proposed roadway would essentially follow the natural contours of the land and require minimal grading and cutback except to provide adequate sight lines to Trestle Glen Boulevard. Cut and fill for the project is balanced. The slope of the proposed roadway would range from 2% to 18% and would meet applicable standards for fire, emergency, utility and service trucks such as refuse collection vehicles. In comparison, Taylor Road, a public street off Paradise Drive, maintains a 25% slope over a considerable distance.

(j) Proposed arrangement of residential units and design of circulation system shall provide harmonious transition from and be compatible with, neighboring development and open space. Monotony in design shall be avoided.

The project is designed to be independent of surrounding neighborhoods in terms of access and respects preservation of open space as about 80% of the site will remain permanently open.

(k) Adequate consideration shall be given to the need for privacy and with minimum visual and aural intrusion into indoor and outdoor living areas from other living areas.

Staff has concluded that with some suggested modifications, the location of the proposed building envelopes would create adequate separation between the future houses and nearby existing homes, insuring the privacy of neighboring residents. Privacy issues can be addressed in much greater detail at the site plan and architectural review permit level. Suggested modifications to address visual issues, such as the "looming effect" are discussed in the "Issues" section below.

(l) Improvements shall be placed so as to minimize intrusion of noise on nearby areas.

The noise study prepared for the project by Lumina Technologies determined that the locations of the homes would not result in any long-term significant noise impacts on the surrounding areas.

(m) Landscaping shall be designed so as to result in the least possible disturbance of natural and/or open areas and shall be compatible with the natural setting. Consideration shall be given to fire protection, water conservation, protection of views and trail areas, and buffering of noise.

Unless otherwise required, landscaping would be limited to the building envelope and landscape envelope areas surrounding the homes, all of which are in the least environmentally sensitive portions of the site. Staff believes that some form of naturalized landscaping should be required along the affected portions of the Trestle Glen Boulevard frontage to soften the effect of residential development from the public street and from Belveron Gardens Subdivision (especially Venus Court and portions of Juno Road).

(n) Utilities shall be underground and street lights, if needed, shall be of low intensity and low in profile.

Streetlights (if any) for this project would be the minimum to achieve public safety. Low level roadway downlighting would be more appropriate, and would be reviewed by the Town during its review of the subdivision improvement drawings and by the Design Review Board during its review of any homes eventually proposed on the site.

(o) Materials and colors used in improvements shall blend into the natural environment to the extent reasonably possible.

This is a standard condition of approval for planned developments in Tiburon. Medium-to-dark earth tone colors are generally preferred by Town Staff as blending better with the surrounding environment. A "design theme", such as Craftsman Style, has been required by the Town on occasion when compatibility concerns are pronounced.

(p) Consistency with other goals and policies of the General Plan Elements shall be demonstrated.

See the General Plan discussion below.

General Plan Consistency

The following section addresses the policies of the Tiburon General Plan that relate to this proposed project:

Land Use Element

LU-B To ensure that all land uses, by type, amount, design, and arrangement serve to protect and enhance the low-density residential and village character and image of the community.

The proposed density of less than one unit per three acres is quite low, roughly one-twelfth that of

Belveron Gardens. The arrangement of units in a clustered manner that respects the

environmental limitations of the site while preserving its most visually prominent portions will

enhance the image of the community.

LU-12 In Planned Residential Districts, new development should be located on the least environmentally sensitive and least hazardous portions of vacant land wherever feasible to promote sound land development and planning practices. Special emphasis shall be placed on keeping ridgelines open and unobstructed to the maximum extent feasible.

Development is clustered in the lower portion of the site away from environmentally sensitive resources on this property. Project construction would avoid oak woodlands on the upper reaches of the property, a riparian drainage channel through the center of the site, and increasingly scarce native grasslands south of the intermittent stream channel. An open space easement would protect these areas. There would be no impact on ridgelines.

Open Space and Conservation Element

OSC-B To provide a flexible guide for landowners to submit proposals for development which will preserve as much open space as possible and result in protection or enhancement to the maximum extent feasible of shorelines, open water, wetlands, significant ridgelines, riparian corridors, steep slopes, rock outcroppings, rare and endangered plant and animal habitat areas, other significant vegetation, and areas of visual importance.

The project would retain the site’s steep slopes, native grasslands, and riparian corridors in private

open space protected by an open space easement. Significant trees and biological areas are

likewise avoided. The secondary ridgeline is completely unaffected.

OSC-2 Growth. While accommodation of growth is an accepted reality, it should be so directed as to preserve and enhance views, ridgelines, significant vegetation, habitats and environmentally sensitive areas to the maximum extent feasible. New development shall be in harmony with adjacent neighborhoods and surrounding open space areas.

The proposed project would maintain approximately 80% of the property as open space outside of building and secondary recreational envelopes. The envelopes would avoid the sensitive vegetation on the upper portions of the property and preserve the mature trees on the site. The design of the project would not excessively impact the views of neighboring residences if suggested modifications are implemented.

OSC-3 Outward Views. Property owners cherish their views. New structures and associated landscaping should be situated or kept low to avoid interference with existing outlooks.

The project building envelopes are designed such that view blockage internal to the subdivision

should not result.

OSC-4 View Corridors. Principal inboard and outboard vistas should be defined and development should be located to protect such vistas to the maximum extent feasible.

The project has the potential to affect primary views from residences at 8 and 11 Turtle Rock Court. Suggested modifications to building envelopes and height limits would eliminate this potential. A series of visual representations of the project will be available for review at the meeting. The visual backdrop of the ridgeline and middle and upper reaches of the property remains intact as open space.

OSC-11 Grading and Tree Removal. The Town shall encourage location of structures in a manner that minimizes tree removal and grading. Specifically, grading shall be kept to a minimum and every effort made to retain the natural features of the land including ridges, rolling land forms, knolls, vegetation, trees, rock outcroppings, and water courses. Where grading is required to stabilize areas of geologic instability, the graded area shall be returned to a natural landform. Excessive grading to stabilize soil is not in the best interest of the Town and is inconsistent with the Town’s desire to retain natural landforms. Therefore, excessive grading is to be avoided to the maximum extent feasible.

The project would avoid removal of all significant trees on the site. Some smaller Bishop Pines would be removed. Roadway grading will be fairly minimal given the topography of the site, and no retaining walls will be required for the roadway.

OSC-15 Site Coverage. To the maximum extent feasible, a goal of 50% of large undeveloped parcels should be considered for retention in permanent open space outside of any parcel or lot which has development potential. Such open space shall be contiguous and link up with adjacent open space whenever practicable. Where a more desirable site plan would result, consideration may be given to larger individual lots. In the latter case, to the maximum extent feasible, 50% of the large undeveloped parcel should be retained in open space and the portions of open space within a parcel or lot with development potential should be restricted from development by open space easement or other appropriate means. This policy shall not require or preclude clustering and protection of open space views shall be accomplished through appropriate building and site coverage restrictions.

Due to environmental constraints, a clustered approach is required for development of the property. Approximately 80% of the property would remain as permanent open space, and the open space will be contiguous to the large open space proposed for the Lower Trestle Glen project.

ISSUES

The subject property is characterized by numerous environmental constraints (especially biological constraints) that confine development to a relatively small portion of the site, resulting in a tightly clustered development. The applicants have worked diligently to design a project that respects the environmental constraints of the property.

Staff believes that the project, on balance, furthers the goals, objectives and policies of the Tiburon General Plan and Tiburon Zoning Ordinance. While highly supportive of the proposed project layout, Staff is of the opinion that certain modifications to the project would serve to soften some of the negatives that can result from tightly clustered projects and increase conformity with the Town’s regulatory documents. These modifications would achieve a superior project from that standpoint. These modifications are discussed below. Staff will have on display at the meeting a colored version of these proposed modifications.

Building Envelopes and Secondary Recreational Envelope

Story poles were erected for this project in August 2000 and have provided an invaluable opportunity to assess potential visual, privacy, and view blockage impacts to the extent feasible without actual house designs for each lot.

Lot 1. Primary view blockage could result for properties located at 8 and 11 Benton Court due to the size and extent of the building envelope on Lot 1. The building envelope should be reduced significantly, the height limit lowered to 24 feet with a partial two-story design, and a height limit of "15 feet from grade" established for the upper portion of the envelope. The home would be placed in the area where the story pole was erected.

Lot 2. The building envelope need not extend as far upslope as shown and the height of the upper area envelope should be reduced to "15 feet above grade". Any home should be limited to a "partial" two-story home.

Lot 3. The building envelope should be scaled back to provide an increased setback of 60 feet from the Trestle Glen Boulevard edge of pavement. A maximum height limit of 24 feet should be specified for the home, with a partial two-story design. The secondary recreational envelope should have its "tail" bobbed off and have a minimum setback of 50 feet from the edge of pavement of Trestle Glen Boulevard. As no buildings will be permitted within this secondary recreational envelope, a smaller setback from Trestle Glen Boulevard is acceptable.

Lot 4. This is the most constricted envelope. Any home should be limited to a partial two-story design. The maximum height should not exceed 30 feet.

As with the Lower Trestle Glen site, a naturalized landscape buffer should be required along the Trestle Glen Boulevard frontage to soften the visual transition to the homes.

Pedestrian Trail Alignment

Staff walked the full length of the proposed pedestrian trail with the applicant and agreed upon a modified alignment that would move the trail slightly further from homes on Benton Court and provide an easier walk by following natural contours more closely.

House Sizes

Proposed house sizes are up to a maximum of 4,800 square feet. These proposed sizes are substantially larger than the surrounding 1950’s-vintage homes, but are similar to large lot homes approved by the Town of Tiburon in newer Precise Development Plans, such as The Preserve off Turtle Rock Court. The Commission may wish to consider further reductions if it does not believe that compatibility can be achieved through the Site Plan & Architectural Review process.

General Plan Circulation Element policy C-34 states that "a future bike lane may be considered along Trestle Glen Boulevard". In order to accommodate this future possibility, the Town will require a ten-foot wide roadway dedication along the entire frontage of the property. According to the Town Engineer, a bike lane project would need to be thoroughly investigated before determining which side of the street it might best be located. It is premature at this time to require any actual installation of improvements along the frontage of this property. If the Planning Commission considers a thorough investigation of a future bicycle lane to be a high priority, it should so recommend to the Town Council. Such a plan would also need to address the frontage below Benton Court and Warren Court, where a widened right-of-way has already been secured. Frontage improvements on a much smaller scale would be required to secure a safe entry for the pedestrian path that connected to Shepherd Way and the Tiburon Ridge Trail.

Agency/Department Comments

Letters have been received from the Town Engineer, Tiburon Fire Protection District, Richardson Bay Sanitary District, and Marin Municipal Water District. These letters are attached as Exhibits 14 through 17. The comments indicate that the project design is feasible in terms of service capacity and provision. These early comments from agencies are reflected in the Initial Study document, and the issues raised therein resolved.

Miscellaneous file letters regarding this site or its vicinity are attached as Exhibits 18 through 21.

FUTURE ACTIONS REQUIRED

The Planning Commission’s approval of this project would be in the form of a recommendation to the Town Council for project approval. The Town Council would then hold a separate public hearing to consider the project and the environmental determination. Should the Commission vote to deny the project, the denial would be final unless appealed to the Town Council.

If the Precise Development Plan is approved by the Town Council, subsequent Town permits would include a Tentative Subdivision Map, Parcel Map, Subdivision Improvement Drawings, Site Plan and Architectural Review approval for each lot, and Building Permits for each residence.

RECOMMENDATION

This hearing will provide the best opportunity to hear from various technical experts who will be present at the meeting, including drainage, traffic, soils, landscaping, and environmental consultants. The Town Engineer will also be present.

Staff recommends that the Planning Commission hold a public hearing on this item.

Staff believes that this project, with some massaging, can be supported and recommended for approval to the Town Council. Staff will prepare a draft resolution for consideration by the Planning Commission at its next meeting on this project.

EXHIBITS

Application Form received 4/27/99.

Adopted Town policies regarding landslide repair, revised May 4, 2000.

Letter from Tiburon Ridge Association dated 12/28/99.

Letter from Town Engineer dated 8/21/00.

Letter from State Department of Fish & Game dated 9/12/00.

Letter from Frank Mullberg, 66 Hacienda Drive, dated 9/14/2000.

Letter from Michael & Sheila Lagios dated 9/26/00.

Letter from Anthony & Pamela Harrington dated 9/27/00.

Letter from Shaun & Janet Coughlin dated 9/28/00.

Letter from Randy Greenberg dated 10/2/00.

Letter from Barry & Rosalind Jekowsky dated 10/2/00.

Letter from Governor’s Office of Planning & Research dated 10/2/00.

Letter from U.S. Fish & Wildlife Service dated 9/20/00.

Comments from Deputy Town Engineer dated 5/21/99.

Comments from Tiburon Fire Protection District dated 5/24/99.

Comments from Richardson Bay Sanitary District dated 1/25/2000.

Comments from Marin Municipal Water District dated 1/25/2000.

Letter from Sharon Callahan, 31 Juno Road, received 3/3/97.

Letter from Sharon Callahan, 31 Juno Road dated 8/12/97.

Letter from Randy Greenberg, 45 Norman day, dated 6/21/99.

Letter from Dr. Michael Lagios, 11 Benton Court, dated 4/20/2000.

 

 

ATTACHMENTS

Full size drawings (4 sheets) prepared by Lawrence P. Doyle dated 4/19/99.

Reduced scale (11" X 17") drawings of the above (for field use).

Additional copy of Initial Study & Draft Mitigated Negative Declaration.

Story Pole and Building Envelope Staking Plan (11" X 17") for field use.

 

 

 

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