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HomeMy WebLinkAbout4.2Item 4.2 TOWN OF LOS ALTOS HILLS August 5, 2010 Staff Report to the Planning Commission RE: MITIGATIVE NEGATIVE DECLARATION AND TENTATIVE PARCEL MAP FOR A THREE -LOT SUBDIVISION: LANDS OF NICHOLSON, END OF EASTBROOK ROAD. FILE 496 -04 -TM -IS -ND -GD. FROM: Cynthia Richardson, Consulting Planner APPROVED BY: Debbie Pedro, AICP, Planning Director—d RECOMMENDATION That the Planning Commission: 1. Review, make comments, and forward a recommendation that, based on the Initial Study, the City Council adopt the Mitigated Negative Declaration and Mitigation Monitoring Program in Attachment 3; and 2. Forward a recommendation that the City Council approve the requested Tentative Parcel Map, based on the findings in Attachment 2 and subject to the conditions of approval in Attachment 1. DISCRETIONARY ACTIONS The following discretionary actions by the City Council are required for approval of the subdivision: 1. Adoption of the Mitigated Negative Declaration and Mitigation Monitoring Program 2. Approval of the Tentative Parcel Map The Planning Commission's actions are recommendations to the City Council. TENTATIVE MAP REVIEW In order to approve a subdivision, the Planning Commission must determine that the project is consistent with the General Plan, Subdivision and Zoning Regulations, and that none of the findings for denial can be made; as specified in Section 66474 of the State Subdivision Map Act. Staff has prepared findings for approval of the project (Attachment 2). Comments on the Tentative Parcel Map have been received from the Town Geotechnical Consultant, the Town Engineer, Santa Clara County Fire Department, PG&E, Cal Trans, California Water Service, Santa Clara Valley Water District the Environmental Design and Protection Committee, the Open Space Committee and the Pathways Committee; and are attached for the Planning Commission's review. I Lands of Nicholson August 5, 2010 Page 2 of 14 Neighboring residents and property owners within 500 feet of the site have been notified of the public hearing. PROJECT DESCRIPTION The applicant is requesting approval of a three -lot subdivision on a 12.56 gross acre parcel located at the end of Eastbrook Road. The property is surrounded by residential properties developed with a mix of one and two story dwellings. The site is gently to moderately sloping with an average 25.09% slope that descends generally west to east toward Eastbrook Road. Hale Creek bisects the property running in a north to south direction and is located on Parcel B. The site is currently vacant but maintains an existing sewer easement and access road running the length of the property from east to west. The existing road does not cross Hale Creek, a turn -around exists on either side. Existing Development * Existing site data is calculated prior to proposed right-of-way dedications. Proposed Development MBA Parcel creage,. ` �)• p�A�reage A Acreage. ' ry, �i) esti Existing 12.56 12.56 25.09 8.50 79,401 44,587 Site * Existing site data is calculated prior to proposed right-of-way dedications. Proposed Development Lot Design and Building Building Parcel A is 1.99 net acres with a slope of 11.90%; Parcel B is 3.21 net acres with a slope of 17.20% and Parcel C is 7.10 net acres with a slope of 33.75%. The Tentative Parcel Map shows a 160 -foot diameter building circle on each parcel, showing that each contains a viable building site. The Tentative Parcel Map shows conceptual site design, building footprints, driveways, and drainage installations. This development is conceptual only and shows that all parcels can be developed to meet Town standards. Once the Tentative Parcel Map is recorded individual site development applications can be made for each parcel. At this time the site specific design of the proposed home will be evaluated through the appropriate MBA Parcel Acreage " A Acreage. ' q $) A 2.25 1.99 11.90 2.155 307790 12,725 B. 3.21 3.21 17.20 2.715 33,395 15,313 C 7.10 7.10 33.75 3.489 26,168 17,445 Lot Design and Building Building Parcel A is 1.99 net acres with a slope of 11.90%; Parcel B is 3.21 net acres with a slope of 17.20% and Parcel C is 7.10 net acres with a slope of 33.75%. The Tentative Parcel Map shows a 160 -foot diameter building circle on each parcel, showing that each contains a viable building site. The Tentative Parcel Map shows conceptual site design, building footprints, driveways, and drainage installations. This development is conceptual only and shows that all parcels can be developed to meet Town standards. Once the Tentative Parcel Map is recorded individual site development applications can be made for each parcel. At this time the site specific design of the proposed home will be evaluated through the appropriate Lands of Nicholson August 5, 2010 Page 3 of 14 public review process where specific conditions will be made. In addition landscape screening will be required for each home site to soften the effect of the new construction. Parcels A and B will be slightly visible from adjacent properties and from.I280. Parcel C will be more visible from surrounding neighbors and from I280 due to the location of the building site. Once a site specific house design is submitted for this site further evaluation will be made through the public hearing process for house design and site screening. Staff has evaluated Parcel C to determine that enough area is free of encumbrances (open space easements, slope, fault trace and property line setbacks) for development. It was determined that roughly 35,300 square feet of unencumbered area was available. Therefore this parcel could support the maximum floor area in a one story structure of 17,445 sq. ft. leaving 8,723 sq. ft. of development area for pools, patios and driveways. The Slope Analysis Map indicates that Parcel C has some areas of steep slope however the conceptual building site is located on slopes between 10% and 20%. In order to meet the Grading Policy any future home would most likely need to be stepped down the hill to limit the amount of grading for the homes construction. Access Driveway access for Parcels A and B will be from a private easement over the Cal Water property off of the end of Eastbrook Road. The shared driveway will serve both parcels. Individual access for Parcel C will be from an existing panhandle served from Dawson Drive. At the time of future construction of the new residence on Parcel C, one eucalyptus tree will be required to be removed for the construction of the future driveway. The future driveway construction to Parcel C may also have impacts to an existing heritage oak tree. The applicant has supplied an arborist report which contains specific conditions for any future grading within the dripline of this tree (Attachment 15). Utilities Water supply will be provided by California Water District. PG&E will provide gas and electric services and Pacific Bell will provide telephone service. All utilities are required to be underground. The Town Engineer has required that all Parcels tie into the Town's sanitary sewer system. An encroachment permit must be obtained from the Public Works Department for all work performed within any public right-of-way. Geotechnical Review The Town's Geotechnical Consultant, Cotton, Shires and Associates has reviewed the proposed Tentative Map and Geologic Investigation provided by the applicant (Steven F. Connelly, dated August 31, 2009 and June 23, 2010). Cotton, Shires and Associates reported that the Project Geotechnical Consultant has adequately characterized site Lands of Nicholson August 5, 2010 Page 4 of 14 conditions and recommended appropriate geotechnical design criteria for future residential development on the proposed Parcels (Attachment 4). Extensive Geotechnical trenching was completed on Parcel A, no fault trace was found. This investigation was prompted by an adjacent neighbor Donald Lull whose property maintains two human habitation building setback lines. The Town Geologist explains that substantial additional scientific information has been learned about the behavior of faults. As a result it has been determined that the suspect zones are bedding plane shears and are not active fault surfaces or fault rupture hazards. Parcel C maintains a fault trace which bisects the property in an east west direction. A 50 foot Human Habitation setback has been shown on the Tentative Parcel Map. The intent is that no enclosed living space is allowed into this setback zone. Uses such as tennis courts, lawns, pools and similar would be examples of acceptable uses within the Human Habitation Building Setback Zone. Another setback that impacts Parcel C is the 25 -foot wide easement over an area with 30- 40% slopes labeled as a slope easement. This is a building setback that applies to all future structures regardless of whether they contain living space. The greater restriction for this 25 -foot setback zone is because any new structures (and associated new slope loading) in this area could trigger slope instability ----failures extending through the face of the cut slope below, damaging the sewer road. Open Space Easement and Pathway Easement No open space easements are needed on Parcel A however an ingress/egress, pathway and public utility easement occurs along the northern property line. An Open Space Easement of approximately 39,000 square feet is proposed on Parcels B. This easement will protect an area of riparian vegetation adjacent to Hale Creek and will provide for a connection of open space from the creek to the adjacent larger area of open space on Parcel C. An ingress/egress, pathway and public utility easement occurs along the northern property line. An Open Space and Pathway Easement of approximately 5.32 acres is proposed on Parcel C which encompasses the steep slopes and areas of dense tree coverage over the northwestern portion of the parcel. A pathway connecting the lower pathway to Dawson Drive has been shown on the Tentative Parcel Map. This location may be modified in the future based on site specific topography and tree vegetation. See Sheet EX -1 and 2 in the Tentative Parcel Map package for more information. Drainage All proposed parcels naturally drain over the site and will be required to maintain the existing flow patterns, using surface flow designs whenever possible. The Town Engineer requires the subdivision improvement plans be submitted with the final map. Lands of Nicholson August 5, 2010 Page 5 of 14 COMMITTEE REVIEW Subdivision Committee The Subdivision Committee comprised of Commissioner Abraham, the Planning Director, the Consulting Planner and Pat Ley, Environmental and Design Protection Committee convened on February 2, 2010 to review and discuss the subdivision proposal. Pursuant to Section 9-1.509 of the Los Altos Hills Municipal Code, neighbors within 500 feet of the property were notified of the hearing. The fact sheet and hearing report from this meeting is attached (Attachments 10 and 11). The issues discussed at the Subdivision Committee meeting are as follows: Neighbors Preston Chan, 11635 Dawson Drive, Don and Janet Lull, 11623 Rebecca Lane, Denise Chuk, 11621 Rebecca Lane and Harry and Karen Emerzian, 11670 Dawson Drive all attended the meeting and had concerns regarding the visibility of the new homes and privacy concerns. They also expressed concern that they were told the property was not able to be developed. Don and Janet Lull had specific privacy concerns and have written a letter to the Town expressing their concerns (Attachment 18). Staff visited the site and finds that because of the tall shrubbery between the Lulls property and Parcel A, the roof of a future two story building may be visible from the adjacent property. Neighbor Parviz Keshtbod, 11627 Rebecca Lane felt the intersection at Eastbrook Avenue and Hwy. 280 is potentially dangerous. Environmental Design and Protection Committee The Committee has no objection to Parcels A and B however they have concerns with Parcel C because of its steep slope and constrained building site (Attachment 12). Pathways Committee The Pathways Committee recommends the following (Attachment 13): 1. A pathway easement over the existing sewer easement from Eastbrook Avenue to the western boundary of the subdivision. 2. A paved path for pedestrians and non -motorized vehicles along the existing sewer easement and an additional native path for horses, adjacent to the paved path where possible. 3. A bridge over Hale Creek suitable for pedestrians, horses, and bicycles. 4. A native path connecting Dawson Drive to the above paths. Lands of Nicholson August 5, 2010 Page 6 of 14 Open Space Committee The Open Space Committee requested that an additional portion of Parcel B be added to the Open Space Easement connecting Hale Creek to the large Open Space Easement area on Parcel C. The Tentative Map has been modified to reflect this request (Attachment 14). ENVIRONMENTAL REVIEW In compliance with the California Environmental Quality Act (CEQA), an Initial Study, Mitigated Negative Declaration and Mitigation Monitoring Program have been prepared for the project. The review period for the Negative Declaration will end on August 16, 2010. The Planning Commission may comment on both the Mitigated Negative Declaration and the Tentative Map. The Mitigated Negative Declaration must be adopted by the City Council before approving the Tentative Map. In order to recommend adoption, the Commission must find that all potential significant environmental effects are addressed through the proposed mitigation measures. Recommended mitigation measures include observation of State and County requirements for handling archaeological remains and artifacts if found, biologic considerations, noise reduction measures and dedication of open space easements. Two specific studies were performed for the Mitigated Negative Declaration, a Traffic Noise Assessment and a Biological Report. A Traffic Noise Assessment Study was prepared by Edward L. Pack, dated January 11, 2010. The study found that all three building site locations exceed required noise exposure for both interior and exterior noise levels. This report finds however that noise exposure can be feasibly mitigated to levels that will be in compliance with the Town of Los Altos Hills General Plan Noise Element (Attachment 16, page 5 and 7). In addition condition numbers 27 and 28 require the applicant to record statements against each parcel ensuring that a qualified noise specialist evaluates the construction drawings to ensure sound mitigation has been addressed and that when constructed the building meets all noise standards. A Biologic Report prepared by Biotic Resources Group, dated January 5, 2010 was prepared for this project, addressing specifically the pathway construction and the Hale Creek Bridge crossing. Specific mitigation measures were recommended and incorporated into the Mitigated Negative Declaration (Attachment 17). CONCLUSIONS Based on the Initial Study, staff has concluded that the proposed subdivision, as mitigated, will not have a significant effect on the environment. The Negative Declaration identifies specific mitigation measures and establishes a Mitigation J J Lands of Nicholson August 5, 2010 Page 7 of 14 Monitoring Program to address the potentially significant environmental impacts identified in the Initial Study. Staff has also concluded that, as documented in the recommended findings of approval, the proposed subdivision is in compliance with the General Plan and Subdivision Ordinance, and would allow development to occur that meets the provisions of the Zoning and Site Development Ordinances. ATTACHMENTS 1. Recommended Conditions of Approval 2. Recommended Findings for Subdivision Approval 3. Initial Study, Negative Declaration & Mitigation Monitoring Program 4. Cotton, Shires and Associates report, July 7, 2010 5. Santa Clara County Fire Department comments, October 27, 2010 6. PG&E letter, February 9, 2005 7. California Water Service Company, November 24, 2009 8. Department of Transportation, May 26, 2009 9. Santa Clara Valley Water District, December 30, 2009 10. Subdivision Committee hearing fact sheet, February 2, 2009 11. Subdivision Committee hearing report, February 2, 2009 12. Environmental Design and Protection Committee comments, November 23, 2010 and February 1, 2010. 13. Pathways Committee minutes, September 28, 2009 14. Open Space Committee comments, November 25, 2010 15. Arborist report prepared by William C. Kleinheinz, Peninsula Tree Care, October 30, 2009 16. Traffic Noise Assessment Study prepared by Edward L. Pack, January 11, 2010 17. Biologic Report prepared by Biotic Resources Group, January 5, 2010 18. Donald and Janet Lull, 11623 Rebecca Lane, letter dated February 10, 2010 19. Tentative Map plan set (Commission only) Lands of Nicholson August 5, 2010 Page 8 of 14 ATTACHMENT 1 RECOMMENDED CONDITIONS FOR THE THREE -LOT SUBDIVISION OF A.12.59 -ACRE PARCEL LANDS OF NICHOLSON (Assessor's Parcel Number 336-42-021) FILE #96 -04 -TM -IS -ND -GD GEOTECHNICAL/EARTHWORK 1. Parcels A and B contain loose backfill materials potentially impacting future structures. All fill material shall be fully remediated or removed. Future residential building and grading plans for these parcels shall be reviewed by the Town Engineer and Town Geotechnical Consultant prior to acceptance of documents for building permit plan check. 2. The applicant for each individual parcel shall submit a site specific grading and drainage plan with the Site Development review process, showing proposed grading and drainage and addressing any geologic concerns. This plan shall be reviewed by the Town Engineer and Town Geotechnical Consultant prior to acceptance of documents for building permit plan -check. LAND AND EASEMENT DEDICATION 3. The applicant shall relocate or abandon existing public utility easements and grant new public utility easements where needed to all utility companies for utility construction and maintenance, including but not limited to: AT&T Telephone Company, Pacific Gas and Electric Company, Comcast Cable Television, and California Water Service Company. The dedications shall all be completed in conjunction with the Final Map approval, to the satisfaction of the City Engineer. 4. The applicant shall dedicate Open Space Easements and Pathway Easements as shown on the Tentative Map. The dedications shall all be completed in conjunction with the Final Map approval to the satisfaction of the Town Engineer. IMPROVEMENTS 5. A grading and drainage plan which includes an erosion control plan shall be submitted for review and approval by the City Engineer as part of the subdivision improvement plans. This plan shall conform to all standards adopted by the Town of Los Altos Hills and shall comply with all appropriate requirements of the Town's NPDES Permit relative to grading and sediment erosion control including but not limited to: a) restricting grading during the moratorium from October 15 to April 15 except with prior written approval from the Town Engineer; b) Lands of Nicholson August 5, 2010 Page 9 of 14 protecting all finished graded slopes from erosion using such techniques as hillside benching, erosion control matting and/or hydro seeding; c) protecting downstream storm drainage inlets from sedimentation; d) appropriate use of sediment rolls to retain sediment on the project site; e) any other suitable measures outlined in the ABAG Manual of Standards. 6. The on-site and off-site drainage improvement shall be designed as surface flow whenever possible to avoid concentration of runoff. The proposed drainage shall be designed to maintain the existing flow patterns. The applicant shall design and construct all subdivision drainage improvements as deemed necessary by the City Engineer. All required drainage improvements shall be constructed or bonded for prior to recordation of the Final Map. 7. All lots within the subdivision shall be connected to the public water system to the satisfaction of the City Engineer and California Water Service Company. Services shall be installed to the property lines or be bonded for prior to recordation of the Final Map. An encroachment permit shall be required to be issued by the Public Works Department for all work proposed within the public right of way. Any necessary fees shall be paid prior to the recordation of the Final Map. 8. All existing and proposed utilities located within the subdivision that serve the subdivision shall be placed underground, in accordance with Subdivision Ordinance, Sec. 9-1.1105. Cable television, gas, electric, and telephone services, to the property lines are included in this requirement. Plans for the location of all such utilities are to be included in the improvement plans for the subdivision. Improvements shall be installed or bonded for prior to recordation of the Final Map. 9. All lots within the subdivision shall be connected to the public sanitary sewer system. An encroachment permit must be obtained from the Public Works Department for all work proposed within the public right of way. Services shall be installed to the property lines or bonded for prior to the recordation of the Final Map. 10. A grading and construction operation plan shall be submitted by the subdivider for review and approval by the City Engineer and Planning Director prior to issuance of any permits for subdivision improvements. The grading/construction operation plan shall address truck traffic issues regarding dust, noise, and vehicular and pedestrian safety on Eastbrook Avenue, Dawson Drive and surrounding roadway; storage of construction materials; placement of sanitary facilities; parking for construction vehicles; and parking for construction personnel. A debris box (trash dumpster) shall be placed on site for collection of construction debris. Arrangements must be made with the Green Waste Recovery, Inc. for the debris box, since they have a franchise with the Town and no other hauler is allowed within the Town limits. J f Lands of Nicholson August 5, 2010 Page 10 of 14 11. Improvement plans for the subdivision shall be submitted for review and approval by the Town Engineer prior to commencement of improvement work. These plans shall conform to all standards adopted by the Town of Los Altos Hills. The subdivider shall be responsible for obtaining all necessary permits from other jurisdictions, including the Department of Fish and Game, Army Corp Engineer, Water Quality Control Board, and Santa Clara Water District. 12. All subdivision improvements shall be constructed to the satisfaction of the Town Engineer or bonded for prior to recordation of the Final Map. 13. All subdivision conditions of approval and subdivision improvements shall be constructed and approved by the Town Engineer prior to submittal of any site development or building permits 14. Any, and all, wells on the property shall be shown on the. Improvement Plans, shall be properly registered with Santa Clara Valley Water District (SCVWD), and shall be abandoned, capped in accordance with the SCVWD standards. PLANNING AND ZONING 15. Payment of park and recreation dedication fees, path in lieu fee and all other applicable fees shall be required prior to recordation of the Final Map. The park and recreation dedication fees shall be provided in accordance with Sections 9.1.1403 and 9.1.1404 of the Los Altos Hills Municipal Code. 16. The property owner shall grant an Open Space Easement to the Town as shown on the Tentative Map page C-2 and C-3. No structures or fencing are permitted and no grading or fill shall be permitted except for a pathway from the existing sewer road to Dawson Drive. Native vegetation may be planted within the easement but no irrigation or sprinkler systems are permitted. 17. The property owner shall dedicate and construct a paved path for pedestrians and non -motorized vehicles along the existing sewer easement and an additional native path for horses, adjacent to the paved path where possible as shown on the Tentative Map to the satisfaction of the City Engineer and the Planning Director. 18. The property owner shall dedicate and construct a native path connecting Dawson Drive to the above paths to the proposed pathway along the sewer road as shown on the Tentative Map to the satisfaction of the City Engineer and the Planning Director. 19. A new pathway bridge crossing Hale Creek shall be constructed with the subdivision improvements to the satisfaction of the City Engineer and the Planning Director. Lands of Nicholson August 5, 2010 Page 11 of 14 20. Construction of the new pathway bridge over Hale Creek shall be designed in a manner to be above the 100 year flood level. Prior to construction, the applicant shall secure all necessary permits from regulatory agencies including but not limited to the California Department of Fish and Game, Regional Water Quality Board, Santa Clara Valley Water District and the Town's Engineering Department. Prior to construction, the applicant shall secure all necessary permits from regulatory agencies. The project construction shall be performed when the creek is dry and shall incorporate erosion control measures to avoid/minimize erosion or sediments from entering downstream aquatic resources during and after construction (i.e., use of silt fencing and/or other approved erosion control features). 21. The applicant shall inform the Town of any damage and shall repair any damage caused by construction of the subdivision improvements to pathways, private driveways and public and private roadways prior to final acceptance of the subdivision by the Town. The applicant shall provide the Town with photographs of the existing conditions of the roadways and pathways prior to recordation of the Final Map. 22. The applicant shall defend, indemnify, and hold harmless the Town of Los Altos Hills and its agents, officers, and employees from any claim, action, or proceeding against the Town of Los Altos Hills or its agents, officers, or employees to attack, set aside, void, or annul an approval of the project to the extent such actions are brought within the time period required by Government Code Section 66499.37 or other applicable law; provided, however, that the Applicant's duty to so defend, indemnify, and hold harmless shall be subject to the Town's promptly notifying the Applicant of any said claim, action, or proceeding and the Town's full cooperation in the defense of such actions or proceedings. 23. Prior to beginning any grading or construction operations, all significant trees shall be fenced with chain link type material at the dripline. Town staff must inspect the fencing and trees to be fenced prior to starting grading or construction. The fence must remain in place throughout the course of construction. No storage of equipment, vehicles or debris shall be allowed within the drip lines. All large and heritage oak trees shall be retained to the greatest extent feasible. 24. The existing abandon water tank shall be removed with the subdivision improvements to the satisfaction of the City Engineer and the Planning Director. 25. The applicant shall ensure that noise generating construction activities are limited to Monday through Saturday between the hours of 8:00 am and 5:30 pm. No heavy noise generating equipment is allowed to be used on Saturdays and no construction is allowed on Sundays or holidays as noted per Chapter 7, Sec.5-7-01 of the Los Altos Hills Municipal Code. 10 Lands of Nicholson August 5, 2010 Page 12 of 14 26. To reduce noise impacts to the anticipated residences located along I280, construction plans for proposed single family dwellings on the newly created parcels shall incorporate appropriate noise reducing measures such as: • Minimum Sound Transmission Class (STC) rating specification for the windows and doors for the noise impacted spaces with a closed window condition. • Exterior noise barriers made of any solid, air -tight material that is acceptable for outdoor use and has a minimum surface weight of 2.5 lbs. per sq. ft. • Earth berms or combinations of berms with shorter fences or walls on top. • Terracing a sloped site where the shoulder of the slope (edge of terrace) acts as a barrier if the receptor is far enough back so that the view to the freeway is shielded. 27. The applicant shall concurrently record a note on the final map and record a deed restriction for each parcel created by the subdivision stating, "To meet the interior noise standard for residential areas of 45 dB CNEL, the construction of single- family dwellings on each created parcel shall implement noise mitigation measures at the time of construction. A qualified noise consultant shall provide documentation at the time of Site Development, identifying architectural or construction measures to .be taken to assure that interior noise levels will not exceed 45 dB CNEL (General Plan, Noise Element Goal 2, Policy 2.2) and exterior noise levels at outdoor living areas will not exceed 60 dB CNEL (General Plan, Land Use and Noise Compatibility Guidelines Figure 7-4)." 28. The applicant shall concurrently record a note on the final map and record a deed restriction for each parcel created by the subdivision stating, "A final acoustical report prepared by a qualified professional to verify a structural attenuation capability to achieve an interior noise standard of 45 dB CNEL (General Plan, Noise Element Goal 2, Policy 2.2) and an exterior noise level at outdoor living areas of 60 dB CNEL, (General Plan, Land Use and Noise Compatibility Guidelines Figure 7-4) shall be submitted to the Town of Los Altos Hills at the time of Site Development. The Planning Department shall review and approve the report prior to the final inspection or occupancy of the new residence." 29. Upon discovering or unearthing any possible burial site as evidenced by human skeletal remains or artifacts, the person making such discovery shall immediately notify the County of Santa Clara Coroner and no further disturbance of. the site may be made except as authorized by the County Coordinator of Indian Affairs. This shall be accomplished to the satisfaction of the County Coroner's Office and the Planning Director, as may be necessary during the construction of the subdivision improvements or individual lot development. 30 Lands of Nicholson August 5, 2010 Page 13 of 14 30. The addresses for the three parcels shall be assigned and approved by the Town as required by the Santa Clara County Fire Department and in accordance with Town policies. 31. The new residences on Parcels A, B & C shown on the Tentative Map Conceptual Development Plan are conceptual only, and no approval of any residence is indicated by approval of the Tentative Map. Site development applications for the new residences shall be submitted to the Planning Department for review and approval. 32. At such time as development on each of the new parcels is proposed, the applicant shall submit a detailed drainage improvement plan for review and approval by the Engineering Department. Peak discharge shall not exceed the existing pre - development peak discharge value of the property. Detention storage must be incorporated into the project to reduce the predicted peak discharge to the pre - development value. The applicant's engineer shall provide . data and peak discharge hydrologic model(s) utilized, as well as, the calculations of the peak discharge value prior and post development. 33. To avoid indirect impacts to nesting birds, bridge construction and pathway construction within the oak woodland shall be scheduled between September 1 and March 1 of any given year. If this schedule is not practical and construction activities must occur during the bird nesting season, a qualified biologist shall conduct a focused survey for nesting birds no more than 15 days prior to construction. If any active bird nests are observed in the work area, the biologist will establish a buffer zone around the nest, wherein work within the buffer zone is postponed until the biologist has determined that all chicks have fledged. FIRE DISTRICT REQUIREMENTS 34. Fire protection improvements, including installation of any required hydrants, shall be constructed as requested by Santa Clara County Fire Department. Improvements shall be constructed and ready for use prior to the recordation of the Final Map, or shall be bonded for. Approved access to each parcel shall be installed prior to commencement of any construction on that lot. 35. Plans for new residences shall be reviewed and approved by the Santa Clara County Fire Department at the time of site development permit application. Conditions that may be applied at that time include, but are not limited to, providing an acceptable water supply based on the size of the new residences, providing an emergency vehicle turnaround, placement of property address signs that are clearly visible from the right-of-way, and providing an approved access system if the lots are fenced and gated. In Lands of Nicholson August 5, 2010 Page 14 of 14 ATTACHMENT 2 RECOMMENDED FINDINGS FOR THE THREE LOT SUBDIVISION OF A 12.56 -ACRE PARCEL LANDS OF NICHOLSON (Assessor's Parcel Number 336-42-021) FILE #96 -04 -TM -IS -ND -GD 1. The subdivision as proposed would create three lots: Lot A would be 2.25 acres in size, with a Lot Unit Factor of 2.16; Lot B would be 3.21 acres in size, with a Lot Unit Factor of 2.72; Lot C would be 7.10 acres in size, with a Lot Unit Factor of 3.49. Each parcel would provide a viable building site. In this and all other respects, the lots conform to the Los Altos Hills Subdivision Ordinance. 2. The proposed subdivision would create three lots that would meet the General Plan guidelines for land with an average slope between 10 and 30 percent, and in all other respects will be consistent with the General Plan. 3. Access to the proposed lots will be provided from a public road. Adequate services including water, gas and electric, telephone, fire protection and police protection are available to serve the subdivision as described in the staff report and the Mitigated Negative.Declaration for the project. Future development on the three parcels will require connection of each parcel to the Los Altos Basin Sewer System. 4. All lots as proposed on the Tentative Map are physically suitable for the proposed future development. The Town Geotechnical Consultant has indicated that stated concerns can be addressed by adherence to the Project Geotechnical Report and conditions of approval for the project: It has been determined that each of the proposed lots contains a suitable building site, and that the proposed density is consistent with the General Plan. 5. All potentially significant environmental effects can be reduced to a level of insignificance as mitigated in the attached Mitigated Negative Declaration. The design of the subdivision and the proposed improvements are not likely to cause substantial environmental damage or to substantially and unavoidably injure fish or wildlife or their habitat. 6. The Town Engineer has reviewed the project and has determined that the design of the subdivision and the improvements will not conflict with easements, acquired by the public at large, for access through or use of the property within the proposed subdivision. Attachment 3 INITIAL STUDY Initial Study Checklist & References Tentative Parcel Map Application Lands of Nicholson 96 -04 -TM -IS -ND -GD Town of Los Altos Hills -Planning Department 26379 Fremont Road Los Altos Hills, CA 94022 Town of Los Altos Hills Initial Study Lands of Nicholson July 28, 2010 Page 2 of 31 In accordance with the policies regarding implementation . of the California Environmental Quality Act of 1970, this document, combined with the attached supporting data, constitutes the initial study on the subject project. This initial study provides the basis for the determination of whether the project may have a significant effect on the environment. If it is determined that the project may have a significant effect on the environment, an environmental impact report will be prepared which focuses on the area of concern identified by this initial study. If it is determined that the project would not have a significant effect on the environment, it is eligible for a Negative Declaration. If it is determined that the proposed project could have a significant effect on the environment, however, the significant effects of the project have been reduced to a less -than -significant level because revisions in the project have been made by or agreed to be the project applicant, then the project would be eligible for a Mitigated Negative Declaration. Environmental Checklist Form 1. Project Title: Nicholson Subdivision 3 -lot Subdivision, (File # 96 -04 -TM -IS -ND - GD) 2. Lead Agency Name and Address: Town of Los Altos Hills, 26379 Fremont Road, Los Altos Hills, California 94022 3. Contact Person and Phone Number: Debbie Pedro, AICP, Planning Director (650) 941-7222 4. Initial Study prepared by: Cynthia Richardson, Consulting Planner (650) 941-7222 5. Project Location: The project is located on the west side of I280 at the terminus of Eastbrook Avenue, Los Altos Hills, CA 94022, APN# 336-42-021. 6. Project Sponsor's Name and Address: W. John Nicholson, 1680 Dell Avenue, Campbell, CA 7. General Plan Designation: R -Residential 8. Zoning: R -A (Residential -Agricultural) 9. Description of Project: The project sponsor is requesting approval of a tentative subdivision map to subdivide one parcel totaling 12.56 gross acres to create three (3) parcels for development of single-family residential homes: Parcel A — 2.25 acres; Parcel B — 3.21 acres and Parcel C — 7.10 acres. Access to parcels A and B is proposed from a new shared driveway off an existing access at the end of Eastbrook Avenue. Parcel C is accessed from a panhandle comzecting to Dawson Drive. All parcels are planned to connect to the existing sewer system and water service will be provided by California Water Service. All existing and new power and utility lines within the subdivision will be placed underground. Town of Los Altos Hills Initial Study Lands of Nicholson July 28, 2010 Page 3 of 31 10. Surrounding Land Uses and Setting: The project is located on the south side of I280 at the end of Eastbrook Avenue. Surrounding land uses include one and two story single-family residences with minimum lot size of 1 acre. 11. Other public agencies whose approval is required: Santa Clara County Fire Department, California State Department of Transportation, Department of Fish and Game, Regional Water Quality Board. Town of Los Altos Hills Initial Study Lands of Nicholson July 28, 2010 Page 4 of 31 ENVIRONMENTAL FACTORS POTENTIALLY AFFECTED: The environmental factors checked below would be potentially affected by this project, involving at least one impact that is a "Potentially Significant Impact" as indicated by the checklist on the following pages. ❑ Aesthetics ❑ Agriculture Resources LJ Air Quality Biological Resources Cultural Resources Geology /Soils ❑ Hazards & Hazardous Z Hydrology / Water Quality ❑ Land Use / Planning Materials ❑ Mineral Resources Noise ❑ Population / Housing ❑ Public Services ❑ Recreation ❑ Transportation/Traffic ❑ Utilities / Service Systems ❑ Mandatory Findings of Significance This Initial study has been prepared in accordance with the California Environmental Quality Act. Information and conclusions in the Initial Study are based upon staff research and the Town's General Plan and Municipal Code. DETERMINATION On the basis of this initial evaluation: I find that the proposed project COULD NOT have a significant effect on the environment, ❑ and a NEGATIVE DECLARATION will be prepared. I find that although the proposed project could have a significant effect on the environment, there will not be a significant effect in this case because the mitigation measures described on attached sheet have been added to the project. A NEGATIVE DECLARATION will be prepared. I find that the proposed project MAY have a significant effect on the environment, ❑ and an ENVIRONMENTAL IMPACT REPORT is required. I find that the proposed project MAY have a significant effect(s) on the environment, but at ❑ least one effect 1) has been adequately analyzed in an earlier document pursuant to applicable legal standards, and 2) has been addressed by mitigation measures based on the earlier analysis as described on attached sheets, if the effect is a "potentially significant impact" or "potentially significant unless mitigated." An ENVIRONMENTAL IMPACT REPORT is required, but it must analyze only the effects that remain to be addressed. I find that although the proposed project could have a significant effect on the environment, there ❑ WILL NOT be a significant effect in this case because all potentially significant effects (a) have been analyzed adequately in an earlier EIR pursuant to applicable standards and (b) have been avoided or mitigated pursuant to that earlier EIR, including revisions or mitigation measures that are imposed upon the proposed project. Signature: Date: July 28, 2010 Debbie Pedro, AICP, Planning Director A "► Town of Los Altos Hills Initial Study Lands of Nicholson July 28, 2010 Page 5 of 31 I. AESTHETICS -- Would the project: a) Have a substantial adverse effect on a ❑ ❑ Q ❑ scenic vista? b) Substantially damage scenic resources, including, but not limited to, trees, rock ❑ ❑ Q ❑ outcroppings, and historic buildings within a state scenic highway? c) Substantially degrade the existing visual ❑ ❑ Q ❑ character or quality of the site and its surroundings? d) Create a new source of substantial light ❑ ❑ Q ❑ or glare which would adversely affect day or nighttime views in the area? DISCUSSION: The proposed project is situated along Highway I280. Currently I280 is not designated as a scenic highway in the area flowing through the Town of Los Altos Hills. Current vistas of the property afford drivers views of open space with trees and open grassland. The largest of the three parcels, Parcel C will maintain over 75% of the 7.10 acres in dedicated Open Space as shown on the Tentative Parcel Map. The Los Altos Hills General Plan identifies important vistas, historic sites, and scenic highways within the Town. None of these resources listed in the General Plan will be significantly impacted by the proposal. Aesthetic impacts due to site grading and residential buildings are expected to be mitigatible when new residences are built. At the time of any proposed development all projects will be evaluated for aesthetic impacts such as structure height, size, setbacks, grading, fencing, tree preservation, and lighting landscaping. Parcel C is the most visible building site from I280 and surrounding properties. Significant landscaping will be required during the Site Development review process for the proposed home once final design drawings are submitted to the Town. Furthermore, the Town has established standards for screening and lighting of all new residential dwelling projects and their associated landscaping and lighting plans are reviewed at publicly noticed hearings. MITIGATION: None Sources: 1,2,5,6 A Town of Los Altos Hills Initial Study Lands of Nicholson July 28, 2010 Page 6 of 31 II. AGRICULTURE RESOURCES— Would the project: a) Convert Prime Farmland, Unique Farmland, or Farmland of Statewide Importance (Farmland), as shown on the ❑ ❑ ❑ maps prepared pursuant to the Farmland Mapping and Monitoring Program of the California Resources Agency, to non- agricultural use? b) Conflict with existing zoning for ❑ ❑ ❑ [� agricultural use, or a Williamson Act contract? c) Involve other changes in the existing environment which, due to their location or ❑ ❑ ❑ nature, could result in conversion of Farmland, to non-agricultural use? DISCUSSION: The proposed subdivision will have no foreseeable impact on Agricultural Resources. The site is not used as agricultural land. MITIGATION: None Source: 8 FBI Town of Los Altos Hills Initial Study Lands of Nicholson July 28, 2010 Page 7 of 31 Th Potentially y Less an � y Less Than Significant gn ficnntw Significant No Impact ith . 1V nigauon Impact Impact ,Incorporation , III. AIR QUALITY -- Would the project: a) Conflict with or obstruct implementation of ❑ ❑ ❑ the applicable air quality plan? b) Violate any air quality standard or contribute substantially to an existing or projected air ❑ ❑ ❑ Q quality violation? . c) Result in a cumulatively considerable net increase of any criteria pollutant for which the project region is non -attainment under an applicable federal or state ambient air quality ❑ ❑ ❑ Q standard (including releasing emissions which exceed quantitative thresholds for ozone precursors)? d) Expose sensitive receptors to substantial pollutant concentrations? ❑ ❑ ❑ 0 e) Create objectionable odors affecting a ❑ ❑ ❑ Q substantial number of people? DISCUSSION: Santa Clara County is currently a non -attainment basin for ozone thresholds but achieves an attainment level for carbon monoxide emissions. The net increase of two developable properties is not a "considerable cumulative impact'. MITIGATION: None Source: 9 0 Town of Los Altos Hills Initial Study Lands of Nicholson July 28, 2010 Page 8 of 31 ` Less,"Than " Sotaln gn ficant w� - Les n Than ign ft Si i th Sig �fcant No Impact p f M►tigat�on act Incorporat�o'n Impact Im IV. BIOLOGICAL RESOURCES -- Would the project: a) Have a substantial adverse effect, either directly or through habitat modifications, on any species identified as a candidate, ❑ Q sensitive, or special status species in local or regional plans, policies, or regulations, or by the California Department of Fish and Game or U.S. Fish and Wildlife Service? b) Have a substantial adverse effect on any riparian habitat or other sensitive natural community identified in local or regional ❑ Q plans, policies, regulations or by the California Department of Fish and Game or US Fish and Wildlife Service? c) Have a substantial adverse effect on federally protected wetlands as defined by Section 404 of the Clean Water Act ❑ ❑ (including, but not limited to, marsh, vernal pool, coastal, etc.) through direct removal, filling, hydrological interruption, or other means? d) Interfere substantially with the movement of any native resident or migratory fish or wildlife species or with established native ❑ Q resident or migratory wildlife corridors, or impede the use of native wildlife nursery sites? e) Conflict with any local policies or ordinances protecting biological resources, ❑ ❑ such as a tree preservation policy or ordinance? f) Conflict with the provisions of an adopted u ❑ 51 Habitat Conservation Plan, Natural ® ❑ Q Community Conservation Plan, or other approved local, regional, or state habitat conservation plan? DISCUSSION: A biological report was prepared by Biotic Resources Group dated January 5, 2010. The report specifically covers the area of improvements associated with the Hale Creels pathway crossing and the pathway construction required for the subdivision. The report is specific to the pathway component of the subdivision because the proposed house locations are outside the creek area and not within oak woodland 9 M ■❑ 0 A Town of Los Altos Hills Initial Study Lands of Nicholson July 28, 2010 Page 9 of 31 areas. The report finds that the riparian areas along Hale Creek to be of lower value because of its narrow width, discontinuous cover, and the close proximity of Highway 280. Areas of oak woodland exist on the property and are traversed by the proposed pathways. Little disturbance to these areas are expected because no trees will be removed and the new pathway will follow an old dirt road. No special status plant species were observed. One Eucalyptus tree is proposed to be removed with the construction of the future driveway to Parcel C. A 35" oak tree may also be slightly impacted during grading for this driveway. The applicant has provided an arborist's letter prepared by certified arborist William C. Kleinheinz of Peninsula Tree Care dated October 30, 2009 which addresses tree protection measures during construction and requires that an arborist be on site when grading occurs for the proposed driveway. No other trees are to be removed with this project. A few special status wildlife species are listed in the California Natural Diversity Database (CNDDB) within the general project vicinity but are not expected to occur on the project site. Two special status wildlife species are listed. The Cooper's hawk (Accipiter cooperii) and the San Francisco dusky -footed woodrat (Neotoma fuscipes annectens) are two species where marginal but potentially suitable habitat exists within the project site. Mitigation measures have been created to mitigate any significant impacts. MITIGATION: Biologic Measure 1: Prior to construction of the pathway bridge over Hale Creek, the applicant shall secure all necessary permits from Santa Clara Valley Water District, Regional Water Quality Control Board and the Department of Fish and Game. The project construction shall be performed when the creek is dry and shall incorporate erosion control measures to avoid/minimize erosion or sediments from entering downstream aquatic resources during and after construction (i.e., use of silt fencing and/or other approved erosion control features). Biologic Measure 2: To avoid impacts to trees the applicant shall implement tree protection measures as depicted on Sheet C-3 the Tentative Parcel Map. These measures include fencing erected along the dripline of retained trees (or tree groupings). Where fencing of the dripline is not feasible (such as along the existing dirt road), protection fencing shall be placed as far outward from the tree trunk as possible. All construction activities, including storage of construction materials and deposition of trash shall be prohibited from the fenced areas. The integrity of the fencing should be checked periodically and repaired if damage is noted. Where excavation is to occur within the dripline of existing trees, the applicant shall hand cut all tree roots greater than 3 inches in diameter. Limb removal shall follow Tree Pruning Best Management Practices as adopted by the International Society of Arboriculture (ISA) and shall be observed by a registered Arborist. Biologic Measure 3: To avoid indirect impacts to nesting birds, bridge construction and pathway construction within the oak woodland shall be scheduled between September 1 and March 1 of any given year. If this schedule is not practical and construction activities must occur during the bird nesting season, a qualified biologist shall conduct a focused survey for nesting birds no more than 15 days prior to construction. If any active bird nests are observed in the work area, the biologist will establish a buffer zone around the nest, wherein work within the buffer zone is postponed until the biologist has determined that all chicks have fledged. Sources: 1,2,5,6,10,20,21 Town of Los Altos Hills Initial Study Lands of Nicholson July 28, 2010 Page 10 of 31 V. CULTURAL RESOURCES — Would the project: a) Cause a substantial adverse change in the Q significance of a historical resource as defined ❑ ❑ ❑ in' 15064.5? b) Cause a substantial adverse change in the significance of an archaeological resource ❑ Q ❑ ❑ pursuant to ' 15064.5? c) Directly or indirectly destroy a unique ❑ ❑ Q paleontological resource or site or unique ❑ geologic feature? d) Disturb any human remains, including ❑ Q ❑ ❑ those interred outside of formal cemeteries? DISCUSSION: The proposed subdivision and anticipated residential development will have no foreseeable impact on Cultural Resources as defined in Title 14; Chapter 3; Article 5; Section 15064.5 of the California Environmental Quality Act. The site does not contain a listed historical building and no known archeological resources exist on the subject property. However, if any artifacts or human remains are discovered during any future grading or construction onsite, work in the vicinity of the find shall stop immediately until a qualified archaeologist can evaluate the site and determine the significance of the find per the mitigation measure described below. MITIGATION: Cultural Measure 1: Upon discovering or unearthing any possible burial site as evidenced by human skeletal remains or artifacts, the person making such discovery shall immediately notify the County of Santa Clara Coroner and no further disturbance of the site may be made except as authorized by the County Coordinator of Indian Affairs. Sources: 3,5,16 J A Town of Los Altos Hills Initial Study Lands of Nicholson July 28, 2010 Page 11 of 31 VI. GEOLOGY AND SOILS -- Would the project: a) Expose people or structures to potential ❑ Q ❑ ❑ substantial adverse effects, including the risk of loss, injury, or death involving: i) Rupture of a known earthquake fault, as delineated on the most recent Alquist-Priolo Earthquake Fault Zoning Map issued by the State Geologist for the area or based on other ❑ Q ❑ ❑ substantial evidence of a known fault? Refer to Division of Mines and Geology Special Publication 42. ii) Strong seismic ground shaking? ❑ Q ❑ ❑ iii) Seismic -related ground failure, including ❑ ❑ ❑ Q liquefaction? iv) Landslides? ❑ Q ❑ ❑ b) Result in substantial soil erosion or the loss of topsoil? ❑ ❑ Q ❑ c) Be located on a geologic unit or soil that is unstable, or that would become unstable as a result of the project, and potentially result in ❑ Q ❑ ❑ on- or off-site landslide, lateral spreading, subsidence, liquefaction or collapse? d) Be located on expansive soil, as defined in Table 18-1-B of the Uniform Building Code. (1994), creating substantial risks to life or ❑ ❑ Q ❑ property? e) Have soils incapable of adequately supporting the use of septic tanks or alternative waste water disposal systems ® ❑ ❑ Q where sewers are not available for the disposal of waste water? DISCUSSION: A fault trace was encountered on Parcel C and consequently a 50 -foot building setback from the fault trace has been shown on the Tentative Parcel Map. According to the fault investigation prepared by Steven. F. Connelly dated May 8, 2001, the geotechnical investigation prepared by United Soil Engineering dated July 2009 and the Supplemental Fault Investigation prepared by Steven F. Connelly on June 23, 2010, mitigatible geological hazards on the property include seismic ground shaking and uncompacted fills. The Town's Geotechnical Engineer has reviewed the reports and concurs with the findings therein. Town of Los Altos Hills Initial Study Lands of Nicholson July 28, 2010 Page 12 of 31 MITIGATION: None Sources: 12, 17, 18 J A Town of Los Altos Hills Initial Study Lands of Nicholson July 28, 2010 Page 13 of') I VII. HAZARDS AND HAZARDOUS MATERIALS -- Would the project: a) Create a significant hazard to the public or ❑ ® ❑ Z the environment through the routine transport, use, or disposal of hazardous materials? b) Create a significant hazard to the public or the environment through reasonably foreseeable upset and accident conditions ❑ ❑ ❑ Q involving the release of hazardous materials into the environment? c) Emit hazardous emissions or handle hazardous or acutely hazardous materials, ❑ ❑ ❑ 0 substances, or waste within one-quarter mile of an existing or proposed school? d) Be located on a site which is included on a list of hazardous materials sites compiled pursuant to Government Code Section ❑ ❑ ❑ 10 65962.5 and, as a result, would it create a significant hazard to the public or the environment? e) For a project located within an airport land use plan or, where such a plan has not been adopted, within two miles of a public airport ❑ ❑ ❑ Q or public use airport, would the project result in a safety hazard for people residing or working in the project area? f) For a project within the vicinity of a private airstrip, would the project result in a safety ❑ ❑ ❑ Q hazard for people residing or working in the project area? g) Impair implementation of or physically Q interfere with an adopted emergency response ❑ ❑ ❑ plan or emergency evacuation plan? h) Expose people or structures to a significant risk of loss, injury or death involving wildland fires, including where wildlands are adjacent ❑ Q ❑ ❑ to urbanized areas or where residences are intermixed with wildlands? DISCUSSION: The proposed subdivision and anticipated residential development does not produce a hazard or hazardous waste and will have no foreseeable impact related to Hazards and Hazardous Materials. The site is not located in an identified location according to CA Government Code 65962.5. Town of Los Altos Hills Initial Study Lands of Nicholson July 28, 2010 Page 14 of 31 The site is located within the Wildland Urban Interface Fire Severity Zone. No construction is proposed at this time other than utility improvements and installation of the new pathway system. At the time new residential construction is proposed the California Building Code, Chapter 7A provides new residential construction methods for homes in a high fire risk zone and will be reviewed and approved by the Santa Clara County Fire District. MITIGATION: None Sources: 13 J , Town of Los Altos Hills Initial Study Lands of Nicholson July 28, 2010 Page 15 of 31 4 kF Potentially %esshThan Less Than S�gn�ficant with' Significant Mingat�on x £ Sign►ficant No Impact * Impact � �> �Trnpact Incorporation VIII HYDROLOGY AND WATER QUALITY -- Would the project: a) Violate any water quality standards or waste ❑ ❑ ❑ 0 discharge requirements? b) Substantially deplete groundwater supplies or interfere substantially with groundwater recharge such that there would be a net deficit in aquifer volume or a lowering of the local groundwater table level (e.g., the production rate of pre- ❑ ❑ ❑ Q existing nearby wells would drop to a level which would not support existing land uses or planned uses for which permits have been granted)? c) Substantially alter the existing drainage pattern of the site or area, including through the alteration of the course of a stream or river, in a ❑ ❑ Q ❑ manner which would result in substantial erosion or siltation on- or off-site? d) Substantially alter the existing drainage pattern of the site or area, including through the alteration of the course of a stream or river, or ❑ ❑ 0 ❑ substantially increase the rate or amount of surface runoff in a manner which would result in flooding on- or off-site? e) Create or contribute runoff water which would exceed the capacity of existing or planned ❑ ❑ Q ❑ stormwater drainage systems or provide substantial additional sources of polluted runoff? f) Otherwise substantially degrade water quality? ❑ ❑ ❑ Q g) Place housing within a 100 -year flood hazard area as mapped on a federal Flood Hazard ❑ ❑ Q ❑ Boundary or Flood Insurance Rate Map or other flood hazard delineation map? h) Place within a 100 -year flood hazard area structures which would impede or redirect flood ❑ ❑ ❑ Q flows? i) Expose people or structures to a significant risk of loss, injury or death involving flooding, ❑ ❑ ❑ Q including flooding as a result of the failure of a levee or dam? j) Inundation by seiche, tsunami, or mudflow? ❑ ❑ ❑ Q Town of Los Altos Hills Initial Study Lands of Nicholson July 28, 2010 Page 16 of 31 DISCUSSION: The proposed subdivision and anticipated residential development will have no immitigatible impact on Hydrology and Water Quality as defined in this section. All proposed parcels naturally drain to the north over the site and will be required to maintain the existing flow patterns, using surface flow designs whenever possible. Limited construction is proposed at this time, including utility improvements and installation of the new pathway system which includes a bridge that will span over Hale Creek. The Town Engineer will require a drainage improvement plan to be submitted prior to construction of any future site development. MITIGATION: Hydrology Measure 1: Construction of the new pathway bridge over Hale Creek shall be designed in a manner to be above the 100 year flood level. Prior to construction, the applicant shall secure all necessary permits from regulatory agencies including but not limited to the California Department of Fish and Game, Regional Water Quality Board, Santa Clara Valley Water District and the Town's Engineering Department. Sources: 2, 11, 14 Town of Los Altos Hills Initial Study Lands of Nicholson July 28, 2010 Page 17 of 31 y s •., f� 3 ess Than Potentially 3 Less Than Significant with' Sigp�ficant Significant No Impact Im act Mitigation Im act ' ; p s, i Y `Incorporation � p #, F IX. LAND USE AND PLANNING -- Would the project: a) Physically divide an established community? ❑ ❑ ❑ Q b) Conflict with any applicable land use plan, policy, or regulation of an agency with jurisdiction over the project (including, but not limited to the general plan, specific plan, ❑ ❑ ❑ Q local coastal program, or zoning ordinance) adopted for the purpose of avoiding or mitigating an environmental effect? c) Conflict with any applicable habitat conservation plan or natural community ❑ ❑ ❑ Q conservation plan? DISCUSSION: The proposed subdivision and anticipated residential development will not physically divide a community. The project complies with the Los Altos Hills General Plan and Subdivision Code. A portion of the project site is located in an area denoted as Open Space Conservation Area on the General Plan Map. The Open Space Committee recommends dedication of an open space easement along the north western portion of Parcel C. The easement is required in order to protect areas of steep slopes and oak tree coverage. An Open Space Easement will also be required on Parcel B over Hale Creek and spanning 25 feet from the top of the creels banks. MITIGATION: None Sources: 4,5,6 Town of Los Altos Hills Initial Study Lands of Nicholson July 28, 2010 Page 18 of 31 X. MINERAL RESOURCES -- Would the project: a) Result in the loss of availability of a known mineral resource that would be of value to the ❑ ❑ ❑ Q region and the residents of the state? b) Result in the loss of availability of a locally -important mineral resource recovery ❑ ❑ ❑ site delineated on a local general plan, specific plan or other land use plan? DISCUSSION: The proposed subdivision and anticipated residential development will not result in a loss of mineral resources. The project is not located in an area known for valued minerals. MITIGATION: None Sources: 5,6,17,18 Town of Los Altos Hills Initial Study Lands of Nicholson July 28, 2010 Page 19 of 31 XI. NOISE --Would the project result in: a) Exposure of persons to or generation of noise levels in excess of standards established ❑ Q ❑ ❑ in the local general plan or noise ordinance, or applicable standards of other agencies? b) Exposure of persons to or generation of excessive groundbome vibration or ❑ ❑ ❑ Q groundborne noise levels? c) A substantial permanent increase in ❑ ambient noise levels in the project vicinity ❑ ❑ above levels existing without the project? d) A substantial temporary or periodic increase in ambient noise levels in the project ❑ ❑ d ❑ vicinity above levels existing without the project? e) For a project located within an airport land use plan or, where such a plan has not been adopted, within two miles of a public airport ❑ ❑ ❑ Q or public use airport, would the project expose people residing or working in the project area to excessive noise levels? f) For a project within the vicinity of a private airstrip, would the project expose people ❑ ❑ ❑ residing or working in the project area to excessive noise levels? DISCUSSION: The proposed subdivision and anticipated residential development will be regulated by the Town's established noise standards. Interim construction noise levels associated with subdivision improvements and future site development will likely periodically exceed 60dB(A) but can be held to less than significant by adherence to Town standards for hours of construction. Once development is complete, day to day living will produce noises such as vehicles and air conditioning units. These types of noises are typical of a residential neighborhood. Further, the Town requires new residences, swimming pools, pool equipment, and air conditioners to demonstrate compliance with Town Noise standards. No immitigatible or new types of noise impacts are anticipated. A Traffic Noise Assessment Study was prepared by Edward L. Pack Associates, INC dated January 11, 2010. Due to noise generated from 1280 freeway, noise levels at the building site ranged from 64 to 67 dB CNEL for Parcel A, 64 to 67 dB Community Noise Equivalent Level (CNEL) for Parcel B and 63 to 66 dB CNEL for Parcel C. The Town's General Plan Noise standards specify noise exposure limit of 60 dB CNEL for residential land use (General Plan, Land Use and Noise Compatibility Guidelines Figure 7-4). Interior noise exposures are limited to 45 dB CNEL in interior living spaces (General Plan, Noise Element Goal 2, Policy 2.2). The Traffic Noise Assessment Study contains general mitigation for both interior and exterior noise attenuation. The report maintains that all parcels with future buildings can be mitigated to an acceptable level for both interior and exterior noise. At such time when the future homes are built a noise Town of Los Altos Hills Initial Study Lands of Nicholson July 28, 2010 Page 20 of 31 report will be required listing any mitigation measures necessary to reduce the noise levels to an acceptable level. MITIGATION: Noise Measure 1: The applicant shall ensure that noise generating construction activities are limited to Monday through Saturday between the hours of 8:00 am and 5:30 pm. No heavy noise generating equipment is allowed to be used on Saturdays and no construction is allowed on Sundays or holidays as noted per Chapter 7, Sec.5-7-01 of the Los Altos Hills Municipal Code. Sources: 5, 6, 19 Town of Los Altos Hills Initial Study Lands of Nicholson July 28, 2010 Page 21 of 31 F 1, rPotentially Less Than. r S�gn�ficant with ' s S� mficanf No Im act E 1Vhtigation 4 g �f smpact , ncorporation pac ant g P I Im t L XII. POPULATION AND HOUSING -- Would the project: a) Induce substantial population growth in an area, either directly (for example, by proposing new homes and businesses) or ❑ ❑ ❑ Q indirectly (for example, through extension of roads or other infrastructure)? b) Displace substantial numbers of existing housing, necessitating the construction of ❑ ❑ ❑ 0 replacement housing elsewhere? c) Displace substantial numbers of people, necessitating the construction of replacement ❑ ❑ ❑ housing elsewhere? DISCUSSION: The proposed subdivision and anticipated residential development will not have a significant impact on population or housing. MITIGATION: None Sources: 2,3,5 r Town of Los Altos Hills Initial Study Lands of Nicholson July 28, 2010 Page 22 of 31 Police protection? ❑ ❑ ❑ Q Schools? ❑ ❑ ❑ Q Parks? ❑ ❑ ❑ Q Other public facilities? ❑ ❑ ❑ Q DISCUSSION: The proposed subdivision and anticipated residential development will not have a foreseeable impact on any public service or facility. MITIGATION: None Sources: 2,3 Potentially Less Significant h wit Less Than Ig t" Mrtigat1on Significant No Impact Impact : Incorporation Impact XIII. PUBLIC SERVICES-- Would the project: a) Would the project result in substantial adverse physical impacts associated with the provision of new or physically altered governmental facilities, need for new or physically altered governmental facilities, the ❑ ❑ ❑ Q construction of which could cause significant environmental impacts, in order to maintain acceptable service ratios, response times or other performance objectives for any of the public services: Fire protection? ❑ ❑ ❑ Q Police protection? ❑ ❑ ❑ Q Schools? ❑ ❑ ❑ Q Parks? ❑ ❑ ❑ Q Other public facilities? ❑ ❑ ❑ Q DISCUSSION: The proposed subdivision and anticipated residential development will not have a foreseeable impact on any public service or facility. MITIGATION: None Sources: 2,3 Town of Los Altos Hills Initial Study Lands of Nicholson July 28, 2010 Page 23 of 31 77777777777777 Less'Thang l � � 'Potentially : � < Less Than: , mficant with SAgn1ficant Sig "gnificanNo Impact Impact Mitigation Impact s Tncorporatkn XIV. RECREATION -- Would the project: a) Would the project increase the use of existing neighborhood and regional parks or other recreational facilities such that ❑ ❑ ❑ Q substantial physical deterioration of the facility would occur or be accelerated? b) Does the project include recreational facilities or require the construction or expansion of recreational facilities which ❑ ❑ ❑ 0 might have an adverse physical effect on the environment? DISCUSSION: The proposed subdivision and anticipated residential development will not have a foreseeable impact on recreation facilities. The Town's Parks and Recreation Department will collect an in lieu fee prior to recordation of the Final Map. MITIGATION: None Sources: 5,6 Town of Los Altos Hills Initial Study Lands of Nicholson July 28, 2010 Page 24 of 31 s _ +� �Less;Than- Potentially Less Than ry Significant Significant with Signicant No Impact Mitigation Impact ` Impact ,� Incorporation A sfi XV. TRANSPORTATION/TRAFFIC — Would the project: a) Cause an increase in traffic which is substantial in relation to the existing traffic load and capacity of the street system (i.e., result in a substantial increase in either the ❑ ❑ Q ❑ number of vehicle trips, the volume to capacity ratio on roads, or congestion at intersections)? b) Exceed, either individually or cumulatively, a level of service standard established by the ❑ ❑ ❑ Q county congestion management agency for designated roads or highways? c) Result in a change in air traffic patterns, including either an increase in traffic levels or ❑ ❑ ❑ Q a change in location that results in substantial safety risks? d) Substantially increase hazards due to a design feature (e.g., sharp curves or dangerous ❑ ❑ ❑ Q intersections) or incompatible uses (e.g., farm equipment)? e) Result in inadequate emergency access? ❑ ❑ ❑ Q f) Result in inadequate parking capacity? ❑ ❑ ❑ Q g) Conflict with adopted policies, plans, or programs supporting alternative transportation ❑ ❑ ❑ Q (e.g., bus turnouts, bicycle racks)? DISCUSSION: The subdivision will create two additional new dwellings. The minor increase in traffic is not anticipated to create traffic congestion on existing local roadways. MITIGATION: None Sources: 1,2,3,5 s Town of Los Altos Hills Initial Study Lands of Nicholson July 28, 2010 Page 25 of 31 XVI. UTILITIES AND SERVICE SYSTEMS— Would the project: a) Exceed wastewater treatment requirements of the applicable Regional Water Quality ❑ ❑ ❑ Q Control Board? b) Require or result in the construction of new water or wastewater treatment facilities or expansion of existing facilities, the ❑ ❑ ❑ Q construction of which could cause significant environmental effects? c) Require or result in the construction of new storm water -drainage facilities or expansion of ❑ ❑ ❑ Q existing facilities, the construction of which could cause significant environmental effects? d) Have sufficient water supplies available to serve the project from existing entitlements ❑ ❑ ❑ Q and resources, or are new or expanded entitlements needed? e) Result in a determination by the wastewater treatment provider which serves or may serve the project that it has adequate capacity to ❑ ❑ ❑ Q serve the project's projected demand in addition to the provider's existing commitments? f) Be served by a landfill with sufficient permitted capacity to accommodate the ❑ ❑ ❑ Q project's solid waste disposal needs? g) Comply with federal, state, and local ❑ ❑ ❑ statutes and regulations related to solid waste? DISCUSSION: The proposed subdivision and anticipated residential development will not have a foreseeable impact on utility and service systems. Water supply will be provided by California Water Service Company. All parcels will be connected to the sanitary sewer system. MITIGATION: None Sources: 1,2,3,15 r Town of Los Altos Hills Initial Study Lands of Nicholson July 28, 2010 Page 26 of 31 Potentially Less fha t Less Than Significant Mgnl S1gn!fcant No Impact scan w th tigat�on :< Impact Impact Incorporation XVII. MANDATORY FINDINGS OF SIGNIFICANCE -- Would the project: a) Does the project have the potential to degrade the quality of the environment, substantially reduce the habitat of a fish or wildlife species, cause a fish or wildlife population to drop below self-sustaining ❑ ❑ ❑ Q levels, threaten to eliminate a plant or animal community, reduce the number or restrict the range of a rare or endangered plant or animal or eliminate important examples of the major periods of California history or prehistory? b) Does the project have impacts that are individually limited, but cumulatively considerable? ("Cumulatively considerable" means that the incremental effects of a project ❑ ❑ ❑ Q are considerable when viewed in connection with the effects of past projects, the effects of other current projects, and the effects of probable future projects)? c) Does the project have environmental effects which will cause substantial adverse effects on ❑ ❑ ❑ Q human beings, either directly or indirectly? DISCUSSION: The proposed project, as mitigated, will not result in a negative impact to the environment, wildlife, plant or historical resource. The project does not have any foreseeable cumulative or unmitigated impacts as defined in this Initial Study. MITIGATION: None Sources: 1-23 Town of Los Altos Hills Initial Study Lands of Nicholson July 28, 2010 Page 27 of 31 MITIGATION MEASURES INCLUDED IN THE PROJECT TO AVOID POTENTIALLY SIGNIFICANT EFFECTS: Biologic Measure 1: Prior to construction of the pathway bridge over Hale Creek, the applicant shall secure all necessary permits from Santa Clara Valley Water District, Regional Water Quality Control Board and the Department of Fish and Game. The project construction shall be performed when the creek is dry and shall incorporate erosion control measures to avoid/minimize erosion or sediments from entering downstream aquatic resources during and after construction (i.e., use of silt fencing and/or other approved erosion control features). Biologic Measure 2: To avoid impacts to trees the applicant shall implement tree protection measures as depicted on Sheet C-3 the Tentative Parcel Map. These measures include fencing erected along the dripline of retained trees (or tree groupings). Where fencing of the dripline is not feasible (such as along the existing dirt road), protection fencing shall be placed as far outward from the tree trunk as possible. All construction activities, including storage of construction materials and deposition of trash shall be prohibited from the fenced areas. The integrity of the fencing should be checked periodically and repaired if damage is noted. Where excavation is to occur within the dripline of existing trees, the applicant shall hand cut all tree roots greater than 3 inches in diameter. Limb removal shall follow Tree Pruning Best Management Practices as adopted by the International Society of Arboriculture (ISA) and shall be observed by a registered Arborist. Biologic Measure 3: To avoid indirect impacts to nesting birds, bridge construction and pathway construction within the oak woodland shall be scheduled between September 1 and March 1 of any given year. If this schedule is not practical and construction activities must occur during the bird nesting season, a qualified biologist shall conduct a focused survey for nesting birds no more than 15 days prior to construction. If any active bird nests are observed in the work area, the biologist will establish a buffer zone around the nest, wherein work within the buffer zone is postponed until the biologist has determined that all chicks have fledged. Cultural Measure 1: Upon discovering or unearthing any possible burial site as evidenced by human skeletal remains or artifacts, the person making such discovery shall immediately notify the County of Santa Clara Coroner and no further disturbance of the site may be made except as authorized by the County Coordinator of Indian Affairs. Hydrology Measure 1: Construction of the new pathway bridge over Hale Creek shall be designed in a manner to be above the 100 year flood level. Prior to construction, the applicant shall secure all necessary permits from regulatory agencies including but not limited to the California Department of Fish and Game, Regional Water Quality Board, Santa Clara Valley Water District and the Town's Engineering Department. Noise Measure 1: The applicant shall ensure that noise generating construction activities are limited to Monday through Saturday between the hours of 8:00 am and 5:30 pm, No heavy noise generating equipment is allowed to be used on Saturdays and no construction is allowed on Sundays or holidays as noted per Chapter 7, Sec.5-7-01 of the Los Altos Hills Municipal Code. Town of Los Altos Hills Initial Study Lands of Nicholson July 28, 2010 Page 28 of 31 Source List: 1. Field Inspection 2. Project Plans 3. Planner's Knowledge of the Area 4. Los Altos Hills Land Use and Zoning Map 5. Los Altos Hills General Plan 6. Los Altos Hills Municipal Code 7. Assessor's Maps, Office of County Assessor, Santa Clara County, 2006-2007 8. State Department of Conservation, Farmland Mapping and Monitoring Program 9. BAAQMD CEQA Guidelines: Assessing the Air Quality Impacts of Projects and Plans, December 1999 10. State Depart ment Fish and Game CNDDB Map 11. Santa Clara Valley Water District Map 12. Geotechnica 1 and Seismic Hazard Zones Map of Los Altos Hills, Cotton Shires and Associates, December 2005 13. DTSC Hazardous Waste and Substa nce Sites List, California Environmental Protection Agency 14. Federal Emer gency Management Agency, Flood Insurance Rate Map, Los Altos Hills, May 18, 2009 15. Sanitar y Sewer Map, Town of Los Altos Hills Engineering Department 16. Santa Clara County Municipal Code Chapter II Indian Burial Grounds (Title B Division B-6) 17. Geotechnica I Investigation reports prepared by United Soil Engineering, report dated July 2009, Fault Investigation prepared by Steven F. Connelly dated May 8, 2001 and the Supplemental Fault Investigation prepared by Steven F. Connelly dated June 23, 2010. 18. Cotton & Shires Assoc. Peer Review Letter December 2, 2009 and July 7, 2010. 19. Traff is Noise Assessment Study prepared by Edward L. Pack Associates, dated January 11, 2010 20. Biological Report prepare d by Biotic Resources Group dated January 5, 2010 21. Arborist letter prepared by Willia m C. Kleinheinz dated October 30, 2009 22. CEQ A Guidelines, 2010 23. Google Earth Exhibit List: 1. Project plans Town of Los Altos Hills Initial Study Lands of Nicholson July 28, 2010 Page 29 of 31 Mitigation Monitoring ProLyram Lands of Nicholson File # 96-04-Tm-IS-ND-GD Mitigation Measure Responsible Department Must Be Completed By Done 1 Biologic Measure 1: Prior to Planning Prior to Grading construction of the pathway bridge over Hale Creek; the applicant shall secure all necessary permits from Santa Clara Valley Water District, Regional Water Quality Control Board and the Department of Fish and Game. The project construction shall be performed when the creels is dry and shall incorporate erosion control measures to avoid/minimize erosion or sediments from entering downstream aquatic resources during and after construction (i.e., use of silt fencing and/or other approved erosion control features). 2 Biologic Measure 2: To Planning Prior to Grading avoid impacts to trees the applicant shall implement tree protection measures as depicted on Sheet C-3 the Tentative Parcel Map. These measures include fencing erected along the dripline of retained trees (or tree groupings). Where fencing of the dripline is not feasible (such as along the existing dirt road), protection fencing shall be placed as far outward from the tree trunk as possible. All construction activities, including storage of construction materials and deposition of trash shall be prohibited from the fenced areas. The integrity of the fencing should be checked periodically and repaired if damage is noted. Where excavation is to occur within Town of Los Altos Hills Initial Study Lands of Nicholson July 28, 2010 . Page 2 of 31 the dripline of existing trees, the applicant shall hand cut all tree roots greater than 3 inches in diameter. Limb removal shall follow Tree Pruning Best Management Practices as adopted by the International Society of Arboriculture (ISA) and shall be observed by a registered Arborist. 3 Biologic Measure 3: To Planning Prior to Grading avoid indirect impacts to nesting birds, bridge construction and pathway construction within the oak woodland shall be scheduled between September 1 and March 1 of any given year. If this schedule is not practical and construction activities must occur during the bird nesting season, a qualified biologist shall conduct a focused survey for nesting birds no more than 15 days prior to construction. If any active bird nests are observed in the work area, the biologist will establish a buffer zone around the nest, wherein work within the buffer zone is postponed until the biologist has determined that all chicks have fledged. 4 Cultural Measure 1: Upon Planning During Grading discovering or unearthing any Operations possible burial site as evidenced by human skeletal remains or artifacts, the person malting such discovery shall immediately notify the County of Santa Clara Coroner and no further disturbance of the site may be made except as authorized by the County Coordinator of Indian Affairs. 5 Hydrology Measure 1: Engineering Prior to Grading Construction of the new pathway bridge over Hale Creek shall be designed in a manner to be above the 100 year flood level. Prior to construction, the applicant Town of Los Altos Hills Initial Study Lands of Nicholson July 28, 2010 Page 3 of 31 shall secure all necessary permits from regulatory agencies including but not limited to the California Department of Fish and Game, Regional Water Quality Board, Santa Clara Valley Water District and the Town's Engineering Department. Noise Measure 1: The Planning During applicant shall ensure that Construction noise generating construction activities are limited to Monday through Saturday between the hours of 8:00 am and 5:30 pm, No heavy noise generating equipment is allowed to be used on Saturdays and no construction is allowed on Sundays or holidays as noted per Chapter 7, Sec.5-7-01 of the Los Altos Hills Municipal Code. TOWN OF LOS ALTOS HILLS NEGATIVE DECLARATION PROJECT TITLE: Lands of Nicholson (3 Lot) PREPARED BY: Cynthia Richardson, Consulting Planner NAME AND ADDRESS OF PROJECT SPONSOR: W. John Nicholson 1680 Dell Avenue Campbell, CA 95008 LOCATION OF PROJECT: End of Eastbrook Avenue, Los Altos Hills, CA 94022 APN# 182-20-012 PROJECT DESCRIPTION: Proposed three (3) lot subdivision of 12.56 gross acres to create three new single family residential properties. Parcel A — 2.25 acres; Parcel B — 3.21 acres and Parcel C — 7.10 acres. Access to parcels A and B is proposed from a new shared driveway off an existing access at the end of Eastbrook Avenue. Parcel C is accessed from Dawson Drive. All parcels are planned to connect to the existing sewer system. Water service will be provided by California Water Service. All existing and new power and utility lines within the subdivision will be placed underground. FINDING: The Town of Los Altos Hills has completed a review of the proposed project, and on the basis of the attached Initial Study, has determined that the project, as mitigated, will reduce impacts to a less than significant level. MITIGATION MEASURES INCLUDED IN THE PROJECT TO AVOID POTENTIALLY SIGNICIANT EFFECTS: Biologic Measure 1: Prior to construction of the pathway bridge over Hale Creels, the applicant shall secure all necessary permits from Santa Clara Valley Water District, Regional Water Quality Control Board and the Department of Fish and Game. The project construction shall be performed when the creek is dry and shall incorporate erosion control measures to avoid/minimize erosion or sediments from entering downstream aquatic resources during and after construction (i.e., use of silt fencing and/or other approved erosion control features). Biologic Measure 2: To avoid impacts to trees the applicant shall implement tree protection measures as depicted on Sheet C-3 the Tentative Parcel Map. These measures include fencing erected along the dripline of retained trees (or tree groupings). Where fencing of the dripline is not feasible (such as along A Mitigation Measures Lands of Nicholson July 28, 2010 Page 2 the existing dirt road), protection fencing shall be placed as far outward from the tree trunk as possible. All construction activities, including storage of construction materials and deposition of trash shall be prohibited from the fenced areas. The integrity of the fencing should be checked periodically and repaired if damage is noted. Where excavation is to occur within the dripline of existing trees, the applicant shall hand cut all tree roots greater than 3 inches in diameter. Limb removal shall follow Tree Pruning Best Management Practices as adopted by the International Society of Arboriculture (ISA) and shall be observed by a registered Arborist. Biologic Measure 3: To avoid indirect impacts to nesting birds, bridge construction and pathway construction within the oak woodland shall be scheduled between September 1 and March 1 of any given year. If this schedule is not practical and construction activities must occur during the bird nesting season, a qualified biologist shall conduct a focused survey for nesting birds no more than 15 days prior to construction. If any active bird nests are observed in the work area, the biologist will establish a buffer zone around the nest, wherein work within the buffer zone is postponed until the biologist has determined that all chicks have fledged. Cultural Measure 1: Upon discovering or unearthing any possible burial site as evidenced by human skeletal remains or artifacts, the person making such discovery shall immediately notify the County of Santa Clara Coroner and no further disturbance of the site may be made except as authorized by the County Coordinator of Indian Affairs. Hydrology Measure 1: Construction of the new pathway bridge over Hale Creek shall be designed in a manner to be above the 100 year flood level. Prior to construction, the applicant shall secure all necessary permits from regulatory agencies including but not limited to the California Department of Fish and Game, Regional Water Quality Board, Santa Clara Valley Water District and the Town's Engineering Department. Noise Measure 1: The applicant shall ensure that noise generating construction activities are limited to Monday through Saturday between the hours of 8:00 am and 5:30 pm, No heavy noise generating equipment is allowed to be used on Saturdays and no construction is allowed on Sundays or holidays as noted per Chapter 7, Sec.5-7-01 of the Los Altos Hills Municipal Code. Debbie Pedro, AICP, Planning Director Date TOWN OF LOS ALTOS HILLS Circulated Adopted on: r&V COTTON, SHIRES AND ASSOCIATES, INC. CONSULTING ENGINEERS AND GEOLOGISTS TO: Cvnthia Richardson Consulting Planner TOWN OF LOS ALTOS HILLS 26379 Fremont Road Los Altos Hills, California 94022 SUBJECT: Supplemental Geotechnical Peer Review RE: Nicholson Subdivision #96 -04 -TM -IS -ND -GD Attaclunent 4 July 7, 2010 L0308C RECEIVED JUL 08 2010 SOWN OF LOS ALTOS HILLS Junipero Serra Fwy, Eastbrook Avenue (APN 336-42-021) At your request, we have completed a supplemental geotechnical peer review of the Tentative Map application using: Supplemental Fault Investigation (letter -report) prepared by Steven F. Connelly, C.E.G., dated June 23, 2010; Tentative Parcel Map, Lands of Nicholson (5 sheets, various scales) prepared by Lea & Braze Engineering, Inc., latest revision date of October 1, 2009; and Fault and Landslide Investigation report), prepa-red b 1 Stevre ! F. Connelly, C.E.G., dated December 1, 2006. 1 In addition, we have reviewed pertinent project documents from our office files (L4600) and inspected a recently advanced exploratory trench at the property with the Project Engineering Geologist. DISCUSSION The applicant proposes to subdivide the subject property into three parcels for future single-family residential development. Conceptual building footprints, driveway Northern California Office 330 Village Lane Los Gatos, CA 95030-7218 (408) 354-5542 o Fax (408) 354-1852 www.cottonshires.com Central California Office 6417 Dogtown Road San Andreas, CA 95249-9640 (209) 736-4252 o Fax (209) 736-1212 Cynthia Richardson July 7, 2010 L0308C Page 2 alignments, fault trace setbacks, and proposed open space easements are depicted on the Tentative Map. In our previous project geotechnical peer review (letter -report dated December 2, 2009), we recommended geotechnical approval of the Tentative Map with conditions that a 25 -foot building setback be respected from the top of the cut slope on Parcel C (as recommended by the Project Geologist), and that appropriate steps be taken during future building permit phases to verify that exploratory trenching sites (located near future improvements) are backfilled to appropriate engineering standards. In January 2010, a local resident indicated that a 1977 Terrasearch investigation for the adjacent subdivision resulted in the establishment of human habitation setback zones from suspected fault traces trending towards the currently proposed subdivision and. specifically the proposed building envelope for Parcel A. This Terrasearch investigation located several shears within the local Monterey Formation bedrock, but indicated that: "no distinctive variety of shear zone was found which could be correlated from one trench to another." Based on discussions with Bill Cotton, there was enough room on the adjoining property to locate desired houses without placing structures over areas where shears were identified. Apparently Terrasearch adopted the conservative position that shears could represent through -going faults and recommended that the human habitation building setback zones (HHBSZ) be established as part of the subdivision. CONCLUSIONS AND RECOMMENDED ACTION Over the last three decades substantial additional scientific information has been obtained about the behavior of faults and specifically about the behavior of thrust faults. Detailed knowledge of seismic issues is also more widespread within the geotechnical profession than was the case in 1977. Based on supplemental exploratory trenching across the trend of the adjacent suspect zones, the Project Engineering Geologist concludes that the noted shears within the local bedrock are bedding plane shears. Such shears likely resulted from regional uplift and folding, and are not active fault surfaces or indicators of fault rupture hazards. This conclusion is consistent with the fact that previous shears identified by Terrasearch could not be correlated between exploratory trenches. Based on our review of the referenced Supplemental Fault Investigation and inspection of site exploratory trenches, we conclude that the Project Engineering Geologist has satisfactorily addressed concerns regarding the projection of human habitation setback zones from the adjacent property. COTTON, SHIRES AND ASSOCIATES, IN Cynthia Richardson Page 3 July 7, 2010 L0308C We do not have geologic or geotechnical objections to the subject Tentative Map application given adoption of the following conditions: 1. Parcels A and B - Parcels A and B are constrained by a loosely backfilled exploratory trenches extending through or close to the future house building envelopes. As recommended by the Project Engineering Geologist, loose backfill materials potentially impacting future structures will require either removal and recompaction to appropriate engineering design standards, special consideration during foundation design (to span areas of weak fill), or removal of fill materials with potential adverse impacts duririg ba-Sement exc9vations. We ecc` rl —!E!P-(' tb- t- fill materials be fully remediated or removed rather than being addressed by foundation design. To verify that site fill materials are properly addressed, future residential building and grading plans for these parcels should be reviewed by the Town Engineer and Town Geotechnical Consultant prior to acceptance of documents for building permit plan -check. 2. Parcel C - The western Parcel C is constrained by a fault setback, recommended 25 -foot setback from top of cut slope (impacts northeastern portion of building envelope), and loosely backfilled fault exploration trenches. Ideally, the building setback from the top of cut slope should be depicted on the Tentative Map. The position of the top of cut slope has been depicted on previous figures prepared by the Project Geologist. To verify that the above noted technical issues are properly addressed, future residential building and grading plans for this parcel should be reviewed by the Town Engineer and Town Geotechnical Consultant prior to acceptance of documents for building permit plan -check. LIMITATIONS This supplemental geotechnical peer review has been performed to provide technical advice to assist the Town with its discretionary permit decisions. Our services have been limited to review of the documents previously identified, and a visual review of the property. Our opinions and conclusions are made in accordance with generally COTTON, SHIRES ANIS ASSOCIATES, INC. Cynthia Richardson Page 4 July 7, 2010 L0308C accepted principles and practices of the geotechnical profession. This warranty is in lieu of all other warranties, either expressed or implied. TS:DTS:kd Respectfully submitted, COTTON, SHIRES AND ASSOCIATES, INC. TOWN GEOTECHNICAL CONSULTANT Ted Sayre Principal Engineering Geologist CEG "1795 David T. Schrier Principal Geotechnical Engineer GE 2334 COTTON, SHIRES AND ASSOCIATES, IN AGll,ARA c FIRE COURTESY 5 SERVICE FIRE DEPARTMENT SANTA CLARA COUNTY 14700 Winchester Blvd., Los Gatos, CA 95032-1818 (408) 378-4010 • (408) 378-9342 (fax) s www.sccfd.org DEVELOPMENT REVIEW COMMENTS CODEISEC. I SHEET I NO. I REQUIREMENT .Attachment 5 V Internationally Accredited Agency PLAN REVIEW NUMBER 0 9 2 6 7 0 BLDG PERMIT NUMBER FILENUMBER 96 -04 -TM -IS -ND -GD Fentative map for proposed 3 -lot subdivision. RECEIVED CJ C l 2, ' 20119 TOWN OF LOS ALTOS HILLS Review of this Developmental proposal is limited to acceptability of site access and water supply as they pertain to fire department operations, and shall not be construed as a substitute for formal plan review to determine compliance with adopted model codes. Prior to performing any work the applicant shall make application to, and receive from, the Building Department all applicable construction permits. No construction plans submitted ath this time. Conditions for construction will be provided at time of submittal and will be based upon codes and standards in effect at time of submittal. No fire department conditions or requirements. Approved as submitted. DATE PAGE CITY PLANS SPECS NEW RMDL AS OCCUPANCY CONST.TYPE APPLICANT LEA &BRAZE ENGINERRING, 10/27/2009 OF --L 1 LAH ® 11 ❑ ❑ 11 DESCRIPTION LOAD DBY SEC FLOOR AREA Residential Development Harding, Doug NAME OF PROJECT: LANDS OF NICHOLSON LOCATION: JUnlper0 Serra REDUCTION FOR FIRE SPRINKLERS: REQUIRED FIRE FLOW TABULAR FIRE FLOW: ®20 PSI: Organized as the Santa Clara County Central Fire Protection District Serving Santa Clara County and the communities of Campbell, Cupertino, Los Altos, Los Altos Hills, Los Gatos, Monte Sereno, Morgan Hill, and Saratoga Pacific Gas and. 11 'Ulm Electric Company February 9, 2005 Town of Los Altos Hills 26379 Fremont Road Los Altos Hills, CA 94022 Attn: Debbie Pedro Fax: 650-941-3160 RE: Tentative Map Review Lands of Nicholson, dated: 04/12/2004 Loc:Eastbrook Ave., Los Altos Hills Two Lots subdivision APN 336-42-021 Town's File: 94 -04 -TM -IS -ND -GD PG&E file: 40322879-y04-mr-235 Dear Sir/ Madam: Land Rights Office RECEIVED FEB 10 2005 TOWN OF LOS ALTOS HILLS Attachment 6 111 Almaden Boulevard, Room 814 P.O. Box 15005 San Jose, CA 95115-0005 We have completed the review of above said Map. PG&E has no objection to the map. PG&E owns and operates a variety of gas and electric facilities which may be located within the proposed project boundaries. Project proponents should coordinate with PG&E early in the development of their project plans to promote the safe and reliable maintenance and operation of existing utility facilities. Any proposed development plans should provide for unrestricted utility access and prevent interference vrith PG&E easements. Activities which may impact our facilities include, but are not limited to, permanent/temporary changes in grade over or under our facilities, construction of structures within or adjacent to PG&E's easements, and planting of certain types of vegetation over, under, or adjacent to our facilities. The installation of new gas and electric facilities and/or the relocation of existing PG&E facilities will be performed in accordance with common law or Rules and Tariffs as authorized by the California Public Utilities Commission. Please contact me at (408)282-7401 if you have any questions regarding our comments. Sincerely, Alfred''oon Land Agent South Coast Area- San Jose 40cOR,� 9. CALIFORNIA WATER SERVICE COMPANY 949 B STREET • LOS ALTOS, CA 94024-6005 EPSEa ``� (650) 917-0152 • FAX (650) 917-0921 November 24, 2009 Town of Los Altos Hills Attn Cynthia Richardson 26379 Fremont Road Los Altos Hills, Ca. 94022 Re: Lands of Nicholson (Rebecca Lane) Attaclunent 7 We acknowledge your request for service on Rebecca Lane in Los Altos Hills. California Water Service Company is prepared to provide potable water service to this location in accordance with the rates, rules, and regulations in effect and on file with the California Public Utilities Commission, or as modified in the exercise of its jurisdiction. Should you have any questions or need further assistance please call (650) 917-0152. Sincerely, Melinda Ray Customer Service Manager California Water Service Company DISTRICT OFFICES: ANTELOPE VALLEY • BAKERSFIELD ^ BAYSHORE • BEAR GULCH • CHICO • DIXON ^ EAST LOS ANGELES • KERN RIVER VALLEY • KING CITY LIVERMORE • LOS ALTOS • MARYSVILLE • OEOVILLE • RANCHO DOMINGUEZ • REDWOOD VALLEY • SAUNAS • SELMA • STOCKTON • VISALIA • WESTLAKE • WILLOWS TRANSPORTATION AND H0U5[NG AGENCY Attaclunent 8 ARNOLD SCHNARZENEGGER.Governor STATE OF CALIFORNIA—BUSINESS, DEPARTMENT OF TRANSPORTATION ° m~- BOX 23660 OAKLAND, CA 94623-0660 (510) 286-4444 TOD (510) 286-4454 May 26, 2009 Stephen R. Carmichael C/O John Nicholson 1680 Dell Avenue Campbell, CA 95008 Dear Mr. Carmichael: 04-SCL-280 14.3 06-6RSO444 This is in regard to your request for any impact by adding one single family hombringing to 'i e �� two single family homes in conjunction with your approved Encroachment Permit number 0406- 6RSO444, which authorized you to install a new driveway approach on State Highway 04-SCtbrook Avenue, tile ,in 280, Post Mile 14.3, near the intersection of southbound off ramp and Eas City of Los Altos Hills. Our review indicates that there will be no traffic impact on the State highway system by adding one single family home in your project, as any traffic impact would be on the local road beyond the State right of way or any fire safety issue. This issue shall be addressed with the local agency. Your permit fee deposit of $246 has been expended for our review time. If you have any questions, please contact Mr. Lalj i Patel at (510) 622-5973 or me at (510) 286-4401. Sincerely, B. DA TES District B anch Chief Office off/ ennits Cc: Stephen R. Carmichael, 4125 Blackford Avenue, # 250, San Jose, CA 95117 ► Pa Attachment 9 Cynthia Richardson From: Kathrin Turner [KTurner@valleywater.org] Sent: Wednesday, December 30, 2009 10:12 AM To: Cynthia Richardson Subject: Eastbrook Avenue Three Lot Subdivision - File No. 96 -04 -TM -IS -ND -GD Dear Ms. Richardson: The Santa Clara Valley Water District (District) staff has reviewed the plans for the Eastbrook Avenue three -lot subdivision, received on October 22, 2009. Hale Creek runs through the center of Parcel B of the proposed subdivision. Since the District does not have any right-of-way at this site, in accordance with the District's Water Resources Protection Ordinance, a District permit is not required for this project. The District is glad to see that the proposed bridge crossing over Hale Creek on Parcel B from the previous plan set is not included in the current set of plans. We have no further comments regarding this project. If you have any questions, please contact me at the number below. Please reference District File No. 30484 on any future correspondence. Thank you, )Td thfl an 7Y. 7-anzor (=I-kturner@vaIIeVwat6r.org Assistant Engineer II Santa Clara Valley Water District Community Projects Review Unit 5750 Almaden Expressway San Jose, CA 95118-3614 6e3 Phone (408) 265-2607 ext. 2586 Fax (408) 979-5635 "Those who dance are considered insane by those who can't hear the music." - George Carlin - 1/4/2010 Attachment 10 Town of Los Altos Hills February 2, 2010 Subdivision Committee Hearing Fact Sheet Project Description: Three Lot Subdivision File Number: 96 -04 -TM -IS -ND -GD Site Address: end of Eastbrook Avenue (APN: 336-42-021) Owner(s): John Nicholson Staff Planner: Cynthia Richardson, Consulting Planner Site Data Net Lot Area: 12.56 acres Average Slope: 25.09% Lot Unit Factor: 8.50 PDnIPnQFTl TIFVPT.nPMTi.NT TARTR *Existing site data is calculated prior to proposed right-ot-way dedications. Grading: Grading for pathways only. Sewer/Septic: Sewer system Environmental Design Committee Comments: Requests sound and visual mitigation. Pathway Committee Comments: Construct pathways as follows: 1. A pathway easement over the existing sewer easement from Eastbrook Avenue to the western boundary of the subdivision. 2. A paved path for pedestrians and non -motorized vehicles and a native path adjacent to the paved path for horses, both within the existing sewer easement. 3. A bridge over Hale Creek suitable for pedestrians, horses, and bicycles. 4. A native path connecting Dawson Drive to the above paths. This native path is to be located between Parcel A and B of the subdivision and to use the existing pathway easement between 11639 and 11635 Dawson Drive. Fire Department Comments: Recommends approval with conditions. Geotechnical Comments: Recommends approval with conditions. Utility Company Comments: Cal Water has no objection; PG&E has no objection A 11.90 2.25 1.99 2.155 30,790 12,725 B 17.20 3.21 3.21 2.715 33,395 15,313 C 33.75 7.10 7.10 3.489 26,168 17,445 Existing 25.09 12.56 12.56 8.50 79,401 44,587 Site* *Existing site data is calculated prior to proposed right-ot-way dedications. Grading: Grading for pathways only. Sewer/Septic: Sewer system Environmental Design Committee Comments: Requests sound and visual mitigation. Pathway Committee Comments: Construct pathways as follows: 1. A pathway easement over the existing sewer easement from Eastbrook Avenue to the western boundary of the subdivision. 2. A paved path for pedestrians and non -motorized vehicles and a native path adjacent to the paved path for horses, both within the existing sewer easement. 3. A bridge over Hale Creek suitable for pedestrians, horses, and bicycles. 4. A native path connecting Dawson Drive to the above paths. This native path is to be located between Parcel A and B of the subdivision and to use the existing pathway easement between 11639 and 11635 Dawson Drive. Fire Department Comments: Recommends approval with conditions. Geotechnical Comments: Recommends approval with conditions. Utility Company Comments: Cal Water has no objection; PG&E has no objection Attachment 11 Town Of Los Altos Dills February 2, 2010 Subdivision Committee Hearing Report Project Description: Three Lot Subdivision File Number: 94 -04 -TM -IS -ND -GD Site Address: End of Eastbrook (Assessors Parcel Number 336-42-021 Owner(s): John Nicholson Staff Planner: Cynthia Richardson, Consulting Planner Attendance: Subdivision Committee: Debbie Pedro, Cynthia Richardson, Commissioner Jim Abraham, Pat Ley. Applicant and representatives: Steve Charmichael, Bob Dwyer, and John Nicholson. Neighbors: Parviz Keshtbod, Preston Chan, Jenny Chan, Don and Janet Lull, Denise Chuk, Karen and Harry Emerzian, Mr. Lee. Environmental Design and Protection Committee Comments: Pat Ley felt that a house on Lot C should not be allowed. She felt that the slope was very steep, the lots had large MDA and MFA and the future homes would be highly visible. Neighbor Comments: • Parviz Keshtbod, 11627 Rebecca Lane, felt that the intersection that turns into the subdivision off Eastbrook is potentially dangerous. • Preston Chan, 11635 Dawson Drive, submitted a letter with the following requests: Installation of a 6' fence along the panhandle at Dawson Drive; Site the house on Lot C as far away a possible from their home; Trim or remove the shrub along the south property line that is leaning over their fence. In addition, the houses on the new lots will be too large, too close to the freeway. Noise and air quality would be issues for the homes. • Don and Janet Lull, 11623 Rebecca Lane, think the property should be left as open space. They were told the property could ' never be developed when they purchased their home 30 years ago. New home on Lot A would have direct views into their home and cause them to lose their views. • Denise Chuk, 11621 Rebecca Lane, has privacy concerns because new homes on Lots A and B would look into her property. • Harry and Karen Emerzian, 11670 Dawson Drive, felt that the height and bulk of the new homes shoufd be reduced on the new lots; they were told previously that the property was not able to be developed. They also felt there would be a lot of new construction traffic on Dawson. They also had concerns about maintenance of the creek; They would like to see the property left in open space. Debbie Pedro, Planning Director Date /4qjSF—GtIV MU Attachment 12 A Subdivision Evaluation OF o OS AL105 Environmental Design and Protection Committee Date: iI2 3617 Grading: Creeks, drainage, easements: Existing Vegetation: 1�441J - - Signifi ant iss es/com ents: r U v it .SCIS &I� �. 3 (04- !�L ' - , j tv; " Environmental Design and Protection Committee merit? i uoL-Q- ReviewetL-by: S • �� - Applicant r 'Wae Name --V d c }- c Address !FC -1—D Site impact/lighting/noise: TONty OF LOS ALTOS'HILLS Date W-'– ' C-0- Creeks, cCreeks, drainage* Existing Vegetation: Significant issues/comments: ��,�z �-��� �--� I,•1 n �:.s�-ems Attachment 13 Draft Extract from Pathway Committee Meeting Sept 28 2009 Regarding Eastbrook subdivision Eastbrook Subdivision (Lands of Nicholson) The PWC reviewed this subdivision on Nov 27, 2006, at which time the proposal. was for a two -lot subdivision. The property lies between Dawson Drive and Interstate 280. Hale Creek runs through it approximately North-South. A paved sewer easement runs approximately East-West and approximately parallel to I-280 through the property from Eastbrook Avenue to the east side of Hale Creek. The pavement resumes on the opposite (West) side of Hale Creek and continues to 12131 Oak Park Court. A gate on Eastbrook provides access to the paved sewer easement. The decision of the PWC on Nov 27 2006 required the following: 1) A pathway easement over the existing sewer easement from Eastbrook Avenue to the western boundary of the subdivision; 2) A paved path for pedestrians and non -motorized vehicles and a native path adjacent to the paved path for horses, both within the existing sewer easement; 3) A bridge over Hale Creek suitable for pedestrians, horses, and bicycles; 4) A native path connecting Dawson Drive to the above paths. This native path is to be located between Parcel A and Parcel B of the subdivision and to use the existing pathway easement between 11639 and 11635 Dawson Drive. The reason for the review was that the owner requested that the PWC review their decision of Nov 27, 2006 to determine whether a) the pathway mentioned in (4) is necessary and b) to obtain relief on the request (2) that the native path be separate from the paved path over the full length of the path. The owners worried that a strict interpretation of (2) could require building separate bridges over Hale Creek for the native and the paved pathways. The owners representative instead proposed building a single wooden bridge to serve both pathways. The PWC pointed out that a pathway on the paved pathway could serve as part of a bicycle route serving Foothill College. The PWC reiterated their desire to have a connecting pat ay to Dawson Drive to provide an alternative outlet for safety, to permit equestrians t optionally bypass the busy exit at Eastbrook and 280, and to provide connecti s to the open space at Dawson, a primary goal of the PWC. The PWC sugge ed?a less intrusive path that would run along the Southern boundary of the pro erty from the driveway at Dawson Drive (it was noted that an easement already .exists along the driveway) to the Southwest corner of the property, then North to the sewer easement and further North to the Northwestern property boundary. The PWC suggested that the path jog East on the sewer easement to permit a more gentle descent to the Northwestern property boundary. The exact route would be chosen in conjunction with the Town Engineering staff. Anna Brunzell moved that the PWC modify requirements 2 and 4 of the Nov 27 2006 decision as follows. (Items 1 and 3 were left unchanged). 2) A paved path for pedestrians and non -motorized vehicles along the existing sewer easement and an additional native path for horses, adjacent to the paved path where possible. 4) A native path connecting Dawson Drive to the above paths. The PWC further requested that when the approximate route of the pathway is determined, the property owners return to the PWC with revised plans and stake the approximate route of the proposed pathway for their review. The motion was seconded by Bill Silver and passed unanimously. P Attachment 14 Cynthia Richardson From: roger@spreen.com Sent: Wednesday, November 25, 2009 3:43 PM To: Cynthia Richardson Cc: couperus@sbcglobal.net Subject: RE: Nicholson Subdivision Cynthia: The requirement we want in that corner is that it not be fence -able, so that we can guarantee an open, land-based (i.e. no grade separation/bridge) connection from the creek's open space easement (the west side of Hale Creek) to the pathway easement (that leads to the large open space easement area). As long as the sewer/utility-access easement that ends there doesn't permit fencing, that should be fine. (I don't see a road on the plan, so I assume you're talking about the "Sanitary Sewer Easement" that runs along there? It looks like the pathway runs along that same strip - are they coincident?) Thanks! Roger -------- Original Message -------- Subject: RE: Nicholson Subdivision From: "Cynthia Richardson"<crichardson@losaltoshills.ca.gov> Date: Mon, November 23, 2009 12:58 pm To: "Roger Spreen" <roger@spreen.com> Hi Roger, I looked at the Nicholson map a little closer and the area that you want us to include in the open space is the existing driveway turn -around at the end of the sewer road. Is that still acceptable to you for open space? ovntK61 RLohnrdson cm-SuLtl.nG -PLcivi.wCr TOWVU of 1.0s Attos WLLS Phone 050941-7222 From: Roger Spreen [mai Ito: roger@spreen.com] Sent: Monday, November 16, 2009 9:38 AM To: Cynthia Richardson Subject: Re: Nicholson Subdivision Hi, Cynthia: We have our monthly committee meeting this Thursday, so I was hoping to hold off comments until then. Will that be ok? Also, are there any particular aspects you would most like comments or validation on from us? Thanks! 11/30/2009 Page 2 of 2 Cheers, Roger On Nov 12, 2009, at 12:15 PM, Cynthia Richardson wrote: Hi Roger, I am the Planner working on the above subdivision. Plans were sent to your committee on October 20, 2009 and I was hoping to receive your comments soon. Please let me know if you have any questions or would like to discuss the project. Thank you. cvvtk a RLrkcirdsm. cowsul,ttwg PLawmr Toww of Los ALtos HULs Phome <60941-7222 11/30/2009 .Peninsula Tree Care State ]License # 674160 Fax: 650-593-9369 Phone: 650-349-9367 October 30, 2009 Regards: Dawson Drive Los Altos, C.A. 94024 To whom this may concern, Attachment 15 I have reviewed the proposed plans of construction, along with a visit to the site located on Dawon Drive, .Los Altos, California. This Oak tree is in fair condition, and the following are bay suggestions. As long as guidelines are taken, the Oak tree should not be in danger of being hurt. I feel that there should be installed a protective barrier fencing at the drip -line of gree, as according to plans. I recommend that there be an Arborist on site whein doing driveway, in case any large roots are encountered. However, if there are any roots encountered they can be addressed at that time. WEMM ► Sincerely, William C. Kieinheinz, Jr Certified Arborist WE -7388A ,I 97s t-imiiLTON AVENUE SUITE 28 SAN JOSE, CA 9511 25 Mr, Bob Dw-sti r The Nicholson C"OMP,lny 100 Dell Avenue C'an Abell, CA 95008 Attachment 16 ;lct{rrsiiCtil (,'t�riltiftca��is° TEL 408.371-1195 FAX 408-3711M t 96 www. packassocia tes. COM Januar• 11" 2f)lt) I'r6 t 0 =1 I -t) 3 � Subject: Traffic Noise Assessment. Study for the Proposed "E,astbrook" Single - l: ttrrily I:)e�-elopinettt, I)awstrrt Drive.. Mrs Altos Mills l:)e ar lvIr. Dwyer: This report presents the results of a noise sasses snte:nt study for the proposed ` FastbroOk" single-family srlhtlivisitan alkalt�, I)tjwseari I)ri�ve In Las Altos hills. Is sltOMM On tlti I'e li.ulti~'ie Parcel N-1 ap. Ref, (a). The exlerior noise CXlttasrtres at the site were; evaluated ag.ainsl the standards of ffie City of Los Altos Hills Noise Elle:nrent, Ref, (h). This. study is aii update; (if a noise; tassessrate:nt study prepared font previous dt veloprile at applic,11ion ill 2004, lief. (c), however. this al)PlicatiOt represents a subdivision of tyre property anly° and does not include specific building plaits or lot layouts. The analysis of the: on -,iter sound level l nae rzst reta7l,nts indictrtc s thtrt the exi t nt noire criv iro t1rrie tits at the prOpOsed sites are clue pritn arily to vehicular trti is sources on Interstate 280, The results of the statdy indicate that noise eXperserrC excesses occur and mitigation ITIe'asures will likely be required upon deQloprtaent of"pre:cise building plaits" Sections I and Il of this' report vtljItrain as stinrnaah;, of our findings and descriptions of noise control naethodolrlgies, respectively. Subsequent sections contain the site, traffic Wid prqjeet descriptions. analyses and evaluations, Attached hereto are Appendices A. 13 and C', Wiaich include tire: lisi of refel-ences, descriptions of the applicable standard:, definitions of the terminology. descriptions of the tte:ncISkal iantrunle:ntatitara used for 'the 1":elcl survey. ventilation requireinents, g ncrad building shell controls. and the tan -site jjoi.se n7rasttrcnrwnt ;lata and calculation tables. MEMBER. ACOUSTICAL SOCIETY OF AMERICA NATIONAL COUNM OF ACOUSTICAL. CONSUL—, ANTS Stiniman, of Findinsts The City' of- Los Altos Hills General Plan Noise Element LISCS the Community Noise 1"cluivalent Level CCN l,`J,) descriptor and specifies an exterior noise eXpOSLIre limit of 60 dB CNEL Im- residential hind use. Interior noise exposures at-(-,, limited to. 45 dB C'Nl','I, in interior living spaces. z As the proposed development sites are on sloping hillsides, much of tile sites are not usable flor exterior living areas, such as rear yards, skvinlining pools, patios, etc. Theretbre. the analysis for the exterior areas is limited to the general building envelope where there is potential for construction of homes and exterior liviril) areas. Figures 1, 2 aad 3 provide IlOiSe eXpOSUrC e0nIOUN, for The buildable areas of the sites at first floor elevations. The noise contours represent feature traffic conditions Land do riot include the aeoustic affects o-l'buildings or grading. Parcel A, The existing exterior noise exposures at the buildable area of parcel A rarige from 64 to f'O dB CNI-1. Under future traffic conditions, the noise exposures are expected to increase to 65 to .68 (IB CNI-L,, Thus, the noise eXPOSUMS Will btu Lip to 8 d13 in excess of the City ref Los Altos Hills Noise Element standards. Parccl B The existing exterior noise exposures tit the buildable area of Parcel B range from 64 to 67 dB CNEL, Under future traffic conditions, the noise exposures are expected to increase to 65 R) 69 dB CNEL. Thus, the noise exposures will be up to 8 dB in excess of the City of` Los Altos hills Noise E.'lement standards. PROP"IED MOD* AGMS & 11 U G{9ctiNNS i 7A .h(`12i S - _.�.- ( �jF F)RE it1Dawl _P.U.E. f ` r l •,•�, �`*+,`�4^`."�' 1a � ftt?tX'GStli 59.430`' F 4 _ P�95 ti) i4.�i43 ` Eh idEifT.. %` DktWAY TO 14' `z (DETAIL t ON —3)PROPOZED ` r \ ._r-- ; ,;,`�`•' �," ,. C3' yj FA S iWAY aras£S URIYE'fl+ ySIOR /`/ <;A� ��` .� f>< � . l —•FdET`� ,DR #J If HETENTi{)di l s C#g.l _ "�i° Ifs CR f>4..h}i."._� sYS7Est _ 6 -R§ J . a 7.• FQR (TtON %IE`-100' fsE n �# c� fYI Ff?UFiG 12Ci� f' `~' -- . r2r�•!' (PIER F A SEAL() r {'. _ 53i d c1 - t§ "tom'"`,. •4i § .. '�' `.� ,_. `;" r.. wow j a / , .f' . i '• , - `t5'r ! 7" F 4 i' I _" W -"• fj� 'Eks i = tf ~� •3 '� F ii ,ii. 86 d8. I I r J, FrtXL fd t:.TR �MS411d r f< '<<[ � .;._—�6°�." (4, 5 ss� •:r„F� `' r -�- -�w urf°�jr� Ac EM t r - F 1 Ei5E3( �aXI R TARK TO — .� 65 ei8' 163E REMO205 ov im \ 51H.tl1' 20 Psi _ 1_ .-, — ROtXGicAi AE1Y—iEh—- ^`—%�...,',..4✓_•. Z-d,.. ' — f SDT FUIU+ 8' PA'RIWAY C Ntf#OE-S I ci(E) EY0i.; j j-Tnf�' i✓�j'4fC w— NY t bT 3,UZY J `01 ---- "`r`- • �''Sr i >.F i i:e t.7 CCS t.il+t % I a, t.i Al o. FIGUR ,5 w i II Eur3.:re Traffic Noise. Exposure Cclrl2aur it7dp fc5r parcL! A •wrt COn1'Ouf s are in df3 CNE i J 1 \' r"ref rt lREB 0QA �ANE' (4 Fi YJOh i �� jt v •-,. y °ci' - _ - i _ •, vn�y EDWARD L PACK ASSOC., WC. .� ' J`. /' p, `" , � § y �-,. ,`;`` •s•n..r� E .,rta3rttsra-tc �I �'�, .� �^� t x� Ftatcuz,.•r ac y,c _'r> 1�:i c�z;z;�i tris 9.5125 Plx 1401;sj.§,t IFstr `•. i sAnit'L'S' ti 1, �(I 16 t.c�'u .I=r:� r,,[ant•GI:ils;a.:.4F15 - v. --- -- C.i_ ..... .._.......... ..... __ .... �`1T q 1 F�T11Ra S' P42tiVAY— Cqt4CEP OPIY:WkY f%f28E3ff}t }a } '•'-"w^' �„ „, ... i"+rZt�O�:D t�r10EPTUI; BASISF {a f4' vovmo tYr a� EA - c r�=:•"`� �:��j."�'''�� , e _-+;,�.�.,,�.,_ Cr ,r RING .•J � :P.il.[� E 5E'lic't.T' .. t U. 1tIRL 68 en "g"§ u E3 •` '"1 qqI. t y s � ,,,.tet +��.7'r i'� • `. 7 ,, l 1 F1JiVRE. 4FE.i r �ti r. tas .•`. r" ' i' J E'xseta�i � .. `� -'t � � , �,;:5� `� m'�.; � /- I:` % 3 _k � �` sy Z �it �, r r r -. r •r f � CLiV • lYli 5 �,`ti \°°a4n`' � �� f.• f.�. �' t�•� ''t �' i -.t t � � a�t+�f y� •.'i: t i � r �r,,��'i �, �i �,r�.�, -� ��, y 67 tie"a¢]'t SPACE �'. A.es... }�t� •��� �' ��-: `' - / <itr r� rr Y� �a i P�CEJ.t 4/ it € 1 W r r 1 wi 1 r TYPE G 3kQ/y7iQN. I ' 1 t; siert.c��l . �:.t�.. � RIC ¢' � • 4• r.l�` � r✓r/ • 1 ` t 1 � Y%Lr��J � ri � `� � •{,� r � �t / r : f< c' • ,�� /. i t......... :.- I f ( �; I' f � � ,� � �/ i, i' %, t � �, t. fit. IIS g � r ! / ( „f �'q�4 ) • WHDADCm 1 , t ' } F#, t (E) 1i1' SSt (0824 (E) 4(f' SQRti �i'ft q/A, l• rl € / hEA' FJ( NT 1} Tpt t I Oi:SPA ,• _y ENT' / r r 30' Bs- E) -ABANDONW f w..'.�.ti.,�Jw„L...c'• � . �• "' • .--P----- 3?7.6Ci' �C '.'`4•,�.... �' {-�-.it-..-"'r` : i +„i •. C � 5tu 0 � � , r N7�a.'a,"{i t'Skr; � '. "^ , ...-..�.�...Y:`rd..a�,q �j �4 .. ,;r.,�, ,�" {'„"� �,.�,�.............._....:..,1,..� � �,. �_r.,..r...rti✓ �.yT ��•• �� P 3 ' rP� ♦11 �� ii 5..+• I t , �. 1. � •,p .. t ��i.S'i i Y IRA ' � li� . l+•:i..; }�.�. 3 <§ u, t '1 \ ♦`.,, ss �. 'i �iit'� f•FY.Y �tf;��. ��:;�;1 p y� (s� i �i �c r�:r 3:3`s—•;.�—•€1�C;'m N Future Traffic Noise Expos:.°Ee� Contour `i,�p for Parcel 3 tS ` T y�,� �3 �%i! t 1 c I Contours are in cin CNEL ; I c • `•, i � � ' ` ' t � ED"r'VAFtt? :, p,:tCf{ ASSOC., €1`Jf. # _ , I �'�� { � � y{�} . � € S e� �` q # ' iY7Y[ti1P cf• 1 ,Niiu{iur3:t ' { i i f it \ f S)'•'�r;F.rSiiJS;3i3 L :�;k: 2q ?L'! San Joe. A 45;25 I� , •:ln, 1 e .,o r . ' S k e`EtU,, .i � u�.�i.`t=iti i3,•Y`� �I// �� 'v• r i € 4` -� '! ` t�. s (: 37 l •: i' n t } aS r I #t r 4 +.`7 4 I,am 2:y I I , 241 i1 tvt, w ixPeh2az :, P.iL ca+; .•, ,.,.._ti'�,. s l`.i:aQi"i"a'3£'_ le� _ i 11 ,C.1NT,. �..,�[•,.t.._i`re=i •°.., .�. .. .. , .. 4 i' i . ._ ``- •,•. u t, � � h/ ter„' y� .. _ _.. _ .. ... .._ ,. y FI c x 1 ti� ttil > r V. . rY 'A�1r. �',��; '>� ' ✓ \' «h � Y � ( 7,� Wj "S"'•`� I l.r ,* �� .S&��„�• `' y_1r�`a''... � -"` `�^ '. 1 '`'��' jy�q,+b•' �''^. f 1 1. _..- .. -� `.-.•..,,V`ti.. + ' Y. '^' .a:+:r.7'r-ti^ ::. Vii`' �r,f'',K d`r- fi� •� 'P sFsxx �tia. ;�•_,�a;°•\ �p ''' ,''i r r / Et & f/�� Far �` ✓ \ �Jrr�• r �!' ✓��I r , D-160' 's•�.\t,,_r ti RaE / 1 •_, STI TRACE ✓ fi s f �'1 ";f , /rf� = P ."` {LOCATION*SiCThiED SMS STES rI F. ods i y��,L � -v<-r �'' -�/a a`"� '! `` '�/`yam iF _ • �� R��f✓v. -.v, r -y _ , • 1�i fr/1iij AX.= T3 r d $ir iiE}ibl�7 , rTJ- , t�G .eek '} Xv��"``�` `. t f'SY3 �� �✓ .r f .fit h S TYPE f FOAM7ibtt f y jam+ 1 (REIT & Gtt3 f 3 f x r r i ',yam r �• s ,f'!`;i.! - � ` � + - r4 140' SETBACK FOR £,TRUCTURRES ONLY ✓ .1�,�d /��;,� �,, i { , /.. f - •', «^' �/ `. r„ .OM1. P 9t St --.- - — - - , . e J; r h �ti'`ri�1 ;SMi ij•`x: r""`i. M`ai -= SSE •.... ..... �.;�.. .,. ...��.��� 'L: �.rt'.y�"�i'�r J�, 4g0. Y1fi£<': 'xt ..' !� Ir� t{r. a;Lc sa' . , 's .E - 67 A �- ._, yrPRI.ii]ECT J Lv E m 11'07 61 t 6%32' "-g s _gip"E1r1sEt f_i C 64 CTS PROTECT id;t% 1 . ! i M Sf rENT rti n - S, Cij✓iJ' r X a \•JP�6,,,.� ��iw,-.,ti , 1 $q i lz u LANDS OF Yr&�z� � \ F� �- FR�61x , ^f /`�E3�C3td 4JE�1V� F (5� O t4 t ` , , } 1. , C �T�� � }1�:t ! 4 Y. }r GGEl4 PiUAL bmwi0.AY? Y t., v �w�..... � �'�t S 1Lf FIGURE 3 Ve Future Traffic Nwie Exposure Contour iu4ap for Parcel C EDWARD L. PACK ASSOC, INC, s Contours are in d8 CNE s .F 1 > t,�✓ utz,r' s.:utno ' a. L ;t `S F\ ,z,SIc 2b 14 ,44:i"1 -1,19a` , ?,� t r f `' r k• s � i FZ � z,� 3 Sart Jv�.. i:� �5 i.�rak' i�S(;F:i17 t• �' } ; ! t '+ a t y a g Jatcaarp 9 <, ati, ( » ti �s pacl ns: vC a.cs COto • ' Jf,2 w. r=S. i d (�° "` 1 �' . « `� w` , b .. Z�,l �-F 4:C� °" 1 e . _._; ira ✓✓s. _3_ Parcel C" The existing: exterior noise exposures at the buildable area or Parcel C range frona ) to tib d13 C'NL.L UID&V Future. traf"f c condition& the noise Cxpasures arc expected to increase to 641 to Cil (113 C'NEL Thus. [lie noise exposures will be up to 7 dB in excess of the City cif Los Altai Hills Noise Clement standards. B. I nterioi° Noise Ex1murtes Precise interior noise exposures cannot be determined without precise building, locations. LIokyever, a 15 decibel reduction is typically applied to the exterior noisc exposure at the building setbttck to cale:uklfe the corresponding interior noise exposure. Based on the exterior noise contours. the first floor interior noise exposures in a home on Parcel A could range from 49 to 52 dB C'NEL tinder existing. traffic conditions and From 50 to 53, dB ONE, under future trafirc conditions. Illus. the noise exposures could be LEP to S dl3 in exce=ss of'tlie City of [,os Altos I Tills Noise Element standards, The first floor- interior noise: exposures in a home on Parcel 13 could range front 49 to 52 dB C'NEL tinder existing trafficconditions and From 50 to ';3 dB CNE1, under future traffic conditions. '1 hUs. the noise exposures could be tip to 8 d13 in excess of the City of Los Altos 1.lills Noise I'lement standards. The first floor interior noise exposures in. a laorne can Parcel C could mntge from 49 to 51 dB CNI L, urader existina, tra(Fic conditions and from 49 to 52 dB C'Nlol, under future; traffic conditions. Thus. the noise. e=xposures Could be up to 7 dB in excess of the City Los Altos Ililts Noise. F.'lenacatt standards. ..4_ The interior noise exposures in second I'loor (()I- higher) living spaces are likely to be slightly Holler (1-4 decibels) than the first t'1001- nOiSC CXPOSLINS. Ylo%vever, these noise exposures Cannot be calculated vvdthota knowledge oi' the t1oor elevations. Interior noise expos.ures could be tip to 57 dB CNEI.- which. is 12 dB in excess ol'the City or Los Altos [;dill Noise .Element standard. As shown above. exterior ;and interior jjoi,,ie exposure excesses wlill occur at the sac and mitigation measures will be required. Genei-alized mitigation rneasurcg are described in Section it, below.. 111 N -litigation Measures and Noise Control Methodologics A,. 'Exterior Noise Conti-oll -f o achieve cornpliance with the 60 dB CNU.I.. exterior noise standard ol'the City ol'Los Altos lulls l`4otic 1,71cment at the exterior living areas ol'the prqject. some type Of noise control barriers will be required, Depending upon grading. setbacks. orientations and locations of* the hones and exterior living areas.. noise barriers typical ly 6 ft. to 8 11t. high would be nccessary. Active areas, such as a tennis court. are often not shielded from noise. depending on the severity of the noise levels, Noise expOSLINS WOW 70 CIB CNF-11., would typically be acceptable for an active (noise generating) area of a site. Noise barriers can be made of tiny solid. air -tight materi'01 that is acceptable fair use outdoors and has a minimum surfince weight of'2.5 Iles. per sq. 11. Acoustical ferice-1, Lire usually made ot'a laver cif plywood sandwiched between courses of redwood boards so that the fence looks like a standard -good neighbor" Fence. The plywood joints are UALlIked to maintain the air-4ight construction. Acoustical fences LIP to .10 ft. high are 1'easible. Barriers can also be made of earth berms or combinations of berms with shorter ti aces or Nvalls oil top. Topography can also help to reduce noise exposed areas where tile nose of a hillside shields an exterior living area. -5 - Noise barrier heights etre determined front the elevation of the noise source (freeway, surface), the location of the barber and the location and elevation of the receptor. For rear yards or patios, the receptor clevrati.on is typically 5 ft. abode the ground (average car height). however, for swirnrttintg pools, people are usually sitting. lying cfoNvIl or in the 11001 such that their cars are lute= to the ground. For people 5itti�t�;. the average ear height is 3 ft.. thus. the necessary noise barrier may be to-wer. Terracing a sloped site: can also aid in Sound reduction Where the shoulder of, the slope (edge. of tile terrace) acts as a barrier if the receptor is far enough back so that the view to the freeway is shielded. A high terrace with a small .fence at the cadge and a landscape buffer to inhibit encroachment. on the terrace: edge can interrupt they line;-ol- sight to the road. thereby-' providing noise reduction, particularly for persons sittimg. lying down or in a sm!it11.1 ing pool. Reducing the: noise: exposures at the proposed sites to levels that are in Complian.cc with the standards or the City of Los ;Altos Hills i\oise ["lenient are feasible: utiliZin" alio of the (above described techniques. TO aChieVe an acoustieally-effiective barrier it must be constructed air -tight, i.e.. without cracks, gaps or other openings. and must provide for long-term durability. Barriers can be constructed of masonry. wood, stucco, concrete, earth berm or a combination thereof and must have a mminium surlace: weight of 2.5 lbs. per sq. It. It wood construction is used. homogeneous sheet rn atLrials are pre kerable to conventional ,000 ienein�,�. as the hitter has a tendenyto warp and {grin openings with age. I lowever. high quality air -tight tongue -and -groove, board and batten or shiphip construction can be used. All connections with posts, pilasters and the building shell mast be sealed air -tight. Gates may be incorporated into the barriers, however. they must be the same height its the main barrier, must meet. the mininiurn sua lace weight requirement and roust fit tight when closed. A grip under a gate: may be Tic, more than l" No openings are permitted between the upper bat 1•ier components and the -,,.round- M B. Interior Noig.Q)_ntrnls Precise interior noise controls cannot be determined without knowledge of. the building heights Lind locations. Because every portion of'the buildable areas of the rites are exposed to noise greater than 60 dB CNI71, the corresponding interior exposures will be higher than 45 dB CNI.,',I,. Therefore., some level <),f noise control will be necessary. HAterior to interior sound transrnission is usunfly mitigated through (lie use of a closed window condition and ,t nifilitnum Sound Transmission Class (STC) rating specification for the window -s and doors flor the noise impacted spaQes. The expected exterior noise exposures at any elevation oFany home that could be constructed to any oFthe proposed sites will be below 75 d13 CNE.L. Therefore. the IICCeSNary windoN,\,-- and door STC ratings WOUld be lower than 35. STC ratings beloev 15 Lire coninion and Iairly simple to obiaill, When windovs and glass doors tire inaintained closed flOr noise co ntrol—some type of, I'llechallical ventilation to assure a habitable environment must be provided. The mechanical ventilation requirements specified by the Uniform Buildin'l, Code (URC) are de scribcd in Appendix B. The windows specified to be maintained closed -are to be opi;rable. as the requirement does not imply a"flxed" condition. The winclows and doers shall be installed in an acousticilily-effeetive manner. To an ally v panels must . acoustic, -effeefive ,vindow construction, the Sliding window I'onn an air -light seal Ahen in the closed position and the ,kindow 1ranies, must be caulked 1w w, to t all opening around their entire perimeter with as non-hardenin"I Caulking Compound to prevent sound infiltration, Exterior doors.mLlSt scai air -tight around the full perimeter when in the closed position. . Please be aware that many dtHII-I)ane window and glass door assemblies have inherent noise reduction problems in tile traffic noise frequency spectrum due t6 resonance that occurs within (lie air space between the window lites, and the noise reduction capabilities vary from nianuftacturer to rmant,&ZICIUrer. Therefore. the acoustical test report ol'all sound rated windows and glass doors should be revievved by a qualified acoustician tel ensure that the chosen windows and doors will adequately reduce (raffic noise to acct puible levels. a d * -7- The window and door sound rating specifications must be determined when t� building plans become available. Ill. Site, 'I't-affic and-Proiect Descriptions The planned development site (APN 336-42-02]) is iocated along Dawson Drive I on the south side ot'l-280 in Los Altos Hills. Pareel A is near the bottom of the hillside arcel 13 is also along; the service along, the service roadN extension of Eastbrook Avenue. road and to the west oi'Nirccl A. Parcel B is closest to 1-280. Parcel C in near the top of the hill along Daws"On Drive. The hillside slopes down to the north toward 1-280, Parcel C is higher in elevation that Pareels A kind B and it slopes down toward the freeway. � the -vc topography, of freeway are partially shielded by irate ming topography, thu,;, much of the first floor elevations receive lower noise levels than corresponding second floor elevations. '['he enfirf- Site is presently VUCaJIL. Surrounding land uses include single- I'amily homes adjacent to the south and west. Single-family homes tarn aero -Ss 1-280 to the north, Magdalena Avenue is to the cast. The (111 -site noise environment is controlled pelmarily by vehicular trafflie sources on 1-280. which carries an Average Daily Traffle (ADT,) volume of 11 8.000 vehieles, as reported by CalTrans. Ref. (d). 'rhe proposed projject includes the subdivision cal' the site into three parcels. Ingress and egress to Parcels A and 11 will be by way, of the existilio access road dint is an extension of 1.:asibrook Avenue, Ingress and egress of Parcel C will be by way of a private driveway off or Dawson Drive. -8 - IV. :1nalysis rof the Noise Levels A. Existin,. Nois4 Levels To determine the existing noise: environment at the site, contirtuous recordings of the sound levels were made; on Septe.n-fiber 8-10. 2004 at two locations for the previous application for the sits:. Additional noise level measurements were made on September 15-16. 2009 at one of the previous rrreasureme:nt locations and tit one ne"k- location. L,oczalion 1 was on Parcel A, 175 ft. Born the centerline of 1-280. at tilt proper'ty line lencing along the access road, directly north of the existing water tank. Location 2 was on Parcel C (formerly Parcel i3) in front of the 31" oak tree, 400 ft. from the centerline Of 1-280. NNoise: level mensttrements were nude at Location 2 in 2004 and in 2009. Location 3 Naas oil Parcel 13, 210 11, From the centerline of 1-280. The sound levels were recorded and processed using Larson -Davis Model 812 Precision Integrating Sound Level Meters. The meters yield. by direct readout. a series oC descriptors or the sound levels versus time. a: described in Appendix 13. and the results are shown in the data table in Appendix C. `:Che measured descriptors include: the Li, lai(,, I=5r), and L)rti, i.e., those levels exceeded for 1%. 10%, 5011K, and 90% of tlae time. :also niettsurtid were the maximum and mininiurn levels and the C011611uous e;CjtriValCIlt-CnCrgy Ie Vtls which are used to calculate [lie CNEL. The ineasurenients were made 'fiir a continuous 214-hOLIr I)CriOCI at each location and included I'epresentative hours of the daytime, Cvening and nighttime periods of' tile C'tii_ L index. i 10 'rite raaeasuretnelats reveal that the 2004 l:,u's at.Location I (Parcel A) ranged front 64.8 to 67.5 dBA during the daytime, 63.0 to 65.1 dBA during the evenings and rrom 52.9 to 653 dBA at night. The 2004 I..G,I's at Location 2 {now Parcel C) ranged front 58.0 to 63.22 dBA during the daytime. from 5S. -O to 59:5 during the evening; and from 49.2 to 62.4 dBA at night. The 2009 ranged from 59.1 to 63.7 dBA during the draytinw. from 57.4 to 60.5 11 during the evening quad rronn 45.0 to 62. .1 dBA at night. The 2009 at Location 3 (nev'Marcel 13) ran�zd from 62.8 to 65.9 dBA during the drayilmer. 59.2 to 02.7 dBA during the evening and froj.-n 49.1 to 01.5 dBA at night. Vehicular traffic noise dissipates at the rate of > to 6 dB for arch doubling of distance: from the source and contains a wide spectrum of Frequency Components (firoan 100 to 10.000 1Ir), which are associated with engine. tire, drivetrain, exhaust and other sources. These Frequency components are centered primarily in the 500 and 100 liz octaves lands. and were used :in determining the noise control naettsures recommended for this prgject. 1t3. Futurc Noise Levels Futur-e traffic volume; data tor 1-280 vvere not available from CulTrans. `I'liere:fore. ren averrage annual traftk growth rate- was calculated frorn the change in traffic volume from 1993 to 2008. The 1903 ADT volume for 1-280 was 97,000vehicles. Itet: (c). 'I'hz 2008 (existing) traffic volume was I18.0)00 vehicles ADT. Tlaus, the ravenage annual growth rate. ".-as calculated to be 1.32r'rf, per year. Applying this growth rate to the future 20 years, the. 2028 traffic volume was calculated to be 153,386 vehicles AUF. This 30% incrca!5e in traffic volume vields a 1 x113 increase in the troflic noise levels. - to - V. Evaluations of the Noise Exposures A. Exteriol- Noise Exposures TO evaluate tile can -:site noise exposures a-ainst the standards of the City, ol'Los Altos Hills Noise Element, the CNEL.,'s for the survey- locations. were calculated by decibel averaging of the Lal's as they apply to the daily time periods of the: CNEL index. L, I The CNL-*I, is at 24-hour noise descriptor that uses the mensured L,,q values to calculate a 24-hour tittle-weightedaverag, � - e mise: exposure. Evening and nighttime penalties of dB and 10 d14. 1-espectivejywere added to tI to account 0 he mensured noise levels u I' r the increased human -sensiLiv-ity to noise during these hours. Adjustments were made to the 111casUred noise levels to account for various setback distances of receptor locations :from the the .t locations using methods established by the Highvvay Research Board. Ref. (1). '['he formula use(! to calculate the CNEL is described in Appendix B. The results of the. calcul-ations indicate that tile noise CXPOWre .,it 111CUSLUCIllent Location I Warcel A), which %,as 175 ft, from the centerline of 1-280. is 68 dil CN1,11. U11dCr existing traffic conditions and tit partially shielded first floor elevations. At unshickled first floor elevations and at 175 It. from the centerline of 1-280, the noise exposure is 71 dB CNIFIL. Thus, the noise exposures at the building site area will be up to 8 dB in execs of the City of Los Altos Hill,-, Noise r�,Iement standards. At measurement Location 2 (11amel C), ti hiQh was 400 It, from the centerline of I- 280, the noise exposure was calculated to be 64 dI3 CNI-A. in 2004 all.d. in 2009.. Thus. the noisy; environment at tile site since the noise study prepared in 2004 has remained relatively ur . ichanged. At approximately 280 ft. from the centerline ofthe road and at the ' first floor eltrvaflon, the noise exposure was calculatedto be 06 dB CNE l:. tinder future traffic conditions. the noise exposure is expected to increase to 67 dB CNEL. Thus. the noise exposures will be tip to 7 dB in excess of the standards of the City of.Los Altos Hills Noise Element. 8 At measurement Location 3 (11<ircel B), which was;21011.4rom theceillerline ofl- 280. the noise eXPOSLIM Was calculated to be 66 (IB CNEL At approximately 190 ft. From the centerline of the road, the noise exposure was calculated to be 67 dB CNI"L, Under future traffic conditions. the noise exposure is expected to increase to 68 dB CNF I... ThUS. the noise CXPOSUI-Cs will be tip to 8 M in excess of the standards cif the Cite of Los Altos Hills Noise Element, B. Interior Noise Exposures calculate the interior anise ZI exposures in project living spaces, a 15 dI3 reduction is applied to the exterior noise exposure at the building setback to represent the attenuation provided by the building shell under annual-mlerctiqe conditions, T lie (mniml- in,vi,zige condition assumes that windows have, sin I a that re e� _dve-pane. single-strengt) ss I a kept open 5011,14 ol'the time for natural ventilation. With exterior noise exposures at first floor elevations up to 68 0 CNI.-J— the corresponding interior noise exposures would be -up to 53 dB CNE -L. Second floor exterior noise exposures could be up to 72 dB CNEL. '17hus. the corresponding second floor interior noise exposures could be up to 571 dB CNEL The interior noise exposures could be Lip to 12 dB in excess of the standards of the City of Los Altos Hills Noise E'lement. As shown by the above M111.1,1tiOnS. exterior and interior noise exposures excesses will occur ,.Ind mitionti c on rileasures will be required, Specific noise control design recornmendations should be prepared by a qualified acoustician once detailed site plans are developed. Generalized mitigation nlemire alternative are discussed in Section I] of this report. A - 12 - his report presents the results of a noise assessment StUdy for the planned "LAstbrook" single-l',imily sut-Klivision along Dawson Drive in Los Altos Hills. '1'1)e study findings for pre -sent conditions are based on field measurements and other data and are correct to the best of out knomledge- Future noise level predictions and the recommendMians where based oil inlzorniatiorl Provided by Cal]'rans. Significant changes in this future traffic VOILIMCS, speed limits., motor vehicle technology, noise regulations, or other change,, beyond our control may produce long rzinge noise results different from our estimates. If"Voll have a1ay CILIC.9tiOnS or would like an elaboration on this report, please Call 1110. Sincerely. I.-'I)WARD L PACK ASSOC- INC. lerfrey.K. Pack President Attachments: Appendices A. B, and C APPENDIX References: (a) Tentative Parcel Tap, .Lands of' Nicholson. by Lea and Braze I:;ngineedng, Inc. July 15, 2009 (b) Noise Ellement of the: Gie:neral .I'Iaai. City of Los Altos Hills, adopted NOVember S. 2007 (c) "Noise Assessment Study- Cor the Planned Single -I gamily Subdivision. Dawvson Drive..'Los Alton, t ill ". by Edward I., Pack Associates. Inc;.. Project No. 30-048. September 72, 2004 (d)vtlot.cLj.uov,`hc,trzti'fc�s.s�it resrltrrii*ditai'0OSall:`r`)80405i.hii13"'. State of California Department ofTrans.portation, Division of Frafiic Operations (cj f993 Irafiic �`ciEaaTies on cartro nia State tlighwwray. Stutz of C'talitiirniaa Department o11'ransportatioil, I3ivision off raf is Operations. July 1994 ( t} Highway Research Board. " 1m}ighway Nol;e-A 13esign Guide liar ll.ighway F aigilice rs". Report 117, 1971 APPENDIX B Noise Standards, Terminology. l.nstrunaentaation. velitilaation Reguir ements and Building: Shell Controls, 1. olie Standards :1a C:ity of Los Altos Hills Noise Element. St:arrdurds The City of Los Altos Hills Noise l: leiaaent of the General 1'l,an, last updated on i�civei�ab� r , 2007, specifies aLan exterior land use coa7ala<itibil'cty noise limit of60 dI3 t,'i?ia9ia unity Noise l qulvralent Level (CNEL) for situde-larnily residential and open space uses, The Noise: t.1enAetat also specifies is limit ail' 4-5 d1l C'NEL of residential interior spaces. B-1 2. Ter mmol( A. Statisticall _Noise Levels Due to the fluctuatingcharacter of urban traffic noise. statistic411 procedures are needed to provide an adequate description of the environment, A series of statistical descriptors have been developed which represent the noise levels exceeded a given pereentai e of* the time. These descriptors are obtained by direct readout of the sound measuring instruments. Sone of the statistical levels used to describe community rioise tyre defined as follo-,vs: 1.1 A noise level exceetd.ed for 1% of tile: time, A noise level exceeded for 10% of the time.. considered to be an "intrusive" level. The noise level exceeded 50% of the time representing) FaII "average" sound level. The noise: level exceeded 90 % ol'the time. designated as a "background" noise level. "I`he continuous equivalent -energy level Is that level of'a steady noise having the same sound energy as a given time varying noise:. The f.,L,► represents the decibel level of the time -:averaged value of. sound energy or sound pressure squared and is the descriptor used to calculate; the i)i�;L, rine{ (:'tNI .L. B-? 13. Community. Noise Eouivallent Level (CNEL The CNEL is a measure of'the CL11"nUlative noise exposure over a24 hour period. The CNE"L index divides the 24 hour day into three subperiods, i.e., the daytime (7:00 am io 7:00 pm). the evening period (7:00 pni to 10.00 pm), and the nighttime period 00:00 pni to 7.00 arn). Also., %veighting factors of 5 and 10 dBA are applied to the evening and riighttime periods. respectively, to aCCOURt for the greater sensitivity of people to noise during those periods. The.CNEL values are calculated from the -nicasured Lq Values in accordance with the f'ollowing mathernatical formula: CNI"ll., : 10,1 10 logznil 2) & (L,+5-+ 10 logjtj3) & (L,+10110 logijO)l - 10 logjt)24 where: L(I 1,, fi)r the daytime (7:00a.m. to 7:00 p.m.,) I., = L,q for the evening (7:00 p.m. to 10:00 p,111.) L, M 1,,q for the nighttime (10:00 p.m. to 7:00 a.m.) 24 indicates the 224 hour period & denotes decibel addition C A -Weighted Sou-nd Level The decibel measure of the sound level utilizinu, the "A" weighted network of v sound level meter is referred to as "MA". The "A" wek"lliting is the accepted standard weialiting system used when noise is measured and recorded for the purpose of' determining total noise levels and conducting statistical analyses of the environment so That the output correlates well with the response ofthe human car. B-3 3. 1 "S fnj ni ell tation Y The ora-siie field measurement data were acquired by the use of one or the i list rLirrients Specified below, which provides at direct read(nit, of the 1. exceedance statistical levels including the equivalent -energy level (1-.,q). hiptit to the instrLinient was provided by a microphone extended to it height ors ft, above the "round on using a tripod or .mast. The "A" '�vcigjiting neiw(yrk and the "Fast' response settinge or the instrument,,; were used in conform ance with the applicable standards. The instruments conforin to American National Standards Institute (ANSI) standard S t.4 for Type I itistrun'ients, and ttll inStrUlnemation Nvas acotistically calibrated before and after field tests to assure 11ccUracv, Instruments used R)r field surveys: Larson -Davis Model 812 Integrating Sound Level Meter Larson -Davis 2900 Real Time Analyzer Ili -tie] &Y KJaer I.Model 2211 Precision So nd Lc),vel Meter 4. Ventilation ReQuiretrients V(�niilation requirements to be applied when windows are maintained closed for noise control are specified in the Uniform Building- Code (UBC), 200, edition, Section 12.033 as: 1101lows' "In lieu of required exterior openings:fear natural ventilation.. a mechanical ventilating system may be provided. Such system shall be capable of providing two air changes per b -our in iguest rooms, dormitories, habitable rooms. and in public corridors with a FflinillIL111.1 of 15 cubic feet per minute (71.11s) of outside air per occupant during such orae as the building is OCCUPiCd." 4-1 Based on our previous experience, a "surnmer switch" on the furnacc I'an is normally considered acceptable as a ventilation system by FHA and other agencies. Air- conditioning is alsc ) an Acceptable syst(*m. B-4 b A Btfildil)L, Shell Conti-Ols Hie following additional precautionary measures are required to assure the orcatest potential for -exterior-to-interior noise attemiation by the recorninended mitiggation nle�lsurcs. These measures [11,)PIV at those UrlitS Where CIOSOLI �windows are required: Unshielded entry doors having a direct or side orientation toward (lie primary noise source MUSt be 1-5/8" or 1-3/4" thick, insulated rnetal or solid -core wood. construction with effective weather seals sl' -could not be Used in these around the full perime tet. ;�\)Jail slots sl doors or in the wall of"a liviv, space, ,,,Is a signil' icant noise leakage can occur through them. It' tiny penetrations, in the building shell are required ror vents, pipingC, conduit,nduit, etc- sound leakage around these penetrations, can be controlled by sealing all cracks and clearance spaces with a non - hardening caulking compound. Fireplaces should be provided with tight -fitting dampers. B-5 APPENDIX C On-Sitc.Noise Measurement Dalai.inclCalculation Tables CNEL CALCULA,riONS CLIENT NIC HOLSON COMRANY FILE' 41-(W PROJECT: NICHOLSON PROPERTY DATE 9/15-1612009 SOURCE 1-280 LOCATION 2 Parcel C fform, Parcel B) Dist To Source 400 ft. TIME Lea Parcel B 210 it. 10"Lecl/10 7:00 AM 63.7 2344228.8 288403'1,5 8:00 AM 63A 2167761,6 9:00 AM 9-00 AM 62.3 1698243.7 10:00 Atkll 612 10,00 AM 601 10223293,0 628 1905460.7 11 00 AM 599 812830.5 1995262.3 12:00 PM 602 16471285 2:00 Pto 1'00 PfA 59x9 977237.2 3-00 FIM 65.4 2= PM 611 1288249.6 65.9 3890451.4 :300 PM 61.8 15135612 22387211 4.00 PM 63,0 1995262.3 SUM= 320643935 7.,.00 PM 5W PM 62.2 1659586-9 810-0 PLA 60.6 6100 pf-14 615 1778279:4 SUM= 18325-6622-8 7,00 PhAl 60-5 1122018.5 Ld= 61'8 8:r_,0 PM 513:5 707945.8 12'00 AM 9 00 PFIA 87.4 549540.9 SUM= 237950-6.1 10 00 PM 56-8 478630.1 Ld= 59,0 11-00 Pte` 54A 275422.9 851138-.0 12 00 AM 52.4 173780.1 5 00 AM 1:00 AM 490 79432.8 6'00 AM 611.5 2:00 AM 48,0 63085.7 100 AM 49,0 79432.8 751 4 00 AM 5111 147910.8 5:00 AM 580 630957.3 CNEL=- 6:00 Ar,.4 621 16218101 SUM= 3550472 7 Ld= 56.0 Da}qinqe Level= 72.6 Evening Level= 68.8 Nighttime Level= 75.5 CNEL-- 64 24-HOUr Lew 60-0 LocAT[6fq3 Dist. To Source TIME Parcel B 210 it. 10"Lecl/10 7;00 AM 64-6 288403'1,5 8-00 AM 65.4 346736&5 9:00 AM 64.6 2884031.5 10:00 Atkll 612 20892961 11'.00 AM 628 1905460.7 12,00 RA 63..11 1995262.3 100 PM 631 2041737.0 2:00 Pto 64,2 25,30268.0 3-00 FIM 65.4 3467368,5 4-00 PM 65.9 3890451.4 5.00 PIA 63.5 22387211 6:00 PM 64,1 2570395.8 SUM= 320643935 7.,.00 PM 62.7 1862G87,1 Ld= 64 3 810-0 PLA 60.6 1148153,6 9:00 PIA 59-2 831763.8 SUM= 3842004.5 %00 PM 58,.4 691831.0 Ld-, 61,1 -11-06PNI 66 5 4.46683.6 12'00 AM 53-6 22908118, 1.00 AM 50.6 114.315 4 2-00 AM 49.6 91201.1 3i430 AM 59 3 851138-.0 4-00 AM 50.7 °11'7489.8 5 00 AM 575 562341.3 6'00 AM 611.5 1412537.5 SUM= 4517124.4 Ld= 57,0 Dayli.me Level= 751 Evening Level= 70-9 Nighttime Level= 76,5 CNEL=- 66 24 -Hour Leq= 62,3 CNEL CALCULATIONS CLIENT S&P ENTERPRISES FILE. 36-048 PROJECT- NICHOLSON PROPERTY DATE: 918.1012-004 SOURCE 1-280 LOCATION I Parcel A Dist To Source 175 ft. TIME I -eq Parcel 8 (Now, Parcel C) 400 ft, 1011-eq/10 7,00 A1110 I7:00 AM 67.3 53703180 E 00 AM 664. 8'00 AM 67,5 5623413.3 61..E 1380384.3 9-00 AM 66.3 4255795.2 912010..8 10:00 AM 64,9 30902954 12 ZO PM 11.00 AM 64.8 30199517 1100 pfill 59:1 12:00 PM 65,1 3235936,6 595 891250,9 voo plo 65A 3467368.5 1258525.4 2:00 PlV1 65,8 3801894.0 51,00 PM 3:00 PI -A 66,9 4897788,2 6-00 PM 60-0 4:00 PM 667 4677351.4 5 9:a 891250.9 5 00 Phi 64.9 3090-795,4 560693A 6:00 PM 65.0 3162277.7 S 0 he, 477021685.3 7:00 prVI 651 3225936,6 Lod 66.0 8:00 PU 63,4 2187761.6 51,9 1548817 9:00 PM 63.0 1995262.3 SUM= 7418960.6 10:00 PM, 615 1412537,5 1-.d= 63,9 11:00 PIVI 59,3 8511380 4:00 AM 55.4 12: 00 AM 56.5 4466816 58.3 676083,0 1:00 AM 54,4 2754229 17378008 SUM= 3970225.0 2.00 AM 53,2 208929.6, Ld= 56,4 3:00 AM 52.9 194984.5 Evening Level= 4:00 AM 55,6 3613078.1 Nighttime Level= 75.9 5:00 AM 608 1202264,4 64 6:00 AM 65,3 3388441.6 S U kl 8343480.2 Ld= 59.7 Daytime Level= 76 8 Evening Level= 717 Nighttime Level= 79.2 CNEL= 68 --2.41:11.2we. Lam= 6,412 LOCATION 2 Dist.. To Source TIME Parcel 8 (Now, Parcel C) 400 ft, 1011-eq/10 7,00 A1110 63,2 200nal E 00 AM 664. 1737800.8 9:00 AM 61..E 1380384.3 10:00 AM 59.6 912010..8 11.00 AM 58.5 7079458 12 ZO PM 58,0 6309573 1100 pfill 59:1 812830.5 2-.00 PM 595 891250,9 100 PM 61,0 1258525.4 4-.00 PM, 60.5 1122018 5 51,00 PM 607 1174897.6 6-00 PM 60-0 1000000 0 SUM= 13718318.1 7,00 KA 5 9:a 891250.9 Ld= 60.6 8,00 pro 58.2 560693A 9100 PM 580 630957.3 SfJtA= 2182901,7 10:00pM 56.9 439778.8 Ld= 58.6 11.00 PIM; 54,5 2818383 12:00 AM 51,9 1548817 I �00 AM 50.6 1148154 2:00 AM 49,2 83176.4 3:00 AM 49.3 851138 4:00 AM 55.4 346736.9 5'00 AM 58.3 676083,0 6: 00 A fAl 62.4 17378008 SUM= 3970225.0 Ld= 56,4 Daytime Level= 714 Evening Level= 68.4 Nighttime Level= 75.9 CNEL= 64 24-1 our Leg= 592 i. Local Candidates/Primarily Formed Committees Q&A November 4, 2008 Election 1. When does a non -incumbent candidate who does not intend to raise or spend $1, 000 or more file the Candidate Campaign Statement Short Form (Form 470)? A: For candidates who raise or spend funds during the first half of the year in connection with a November election, the Form 470 covering 2008 must be filed by July 31, 2008. If no funds are raised or spent during the first half of the year, the Form 470 may be filed with the candidate's declaration of candidacy, but must be filed no later than the deadline for the first pre-election statement (October 6 for the November 4 election). 2. A local officeholder filed Form 470 on July 31 for the first six months of 2008. In September, she decides to run for reelection in the November election and opens a campaign committee. Must she file the Form 470 Supplement? A: Yes, because the officeholder intends to raise or spend $1,000 or more in connection with the election, the Form 470 Supplement must be filed. 3. Must a candidate file a late independent expenditure report for payments made by the candidate's controlled committee on his/her behalf during the 16 days prior to the election? A: No. An "independent expenditure" is a payment made by a third party to support or oppose a candidate — and which is not made in coordination or consultation with the candidate. Therefore, payments made from the candidate's own controlled committee would not be considered "independent expenditures" if they were made on his or her behalf, even if they were made in opposition to the candidate's opponent. In addition, Gov. Code section 85501 prohibits a candidate's controlled committee from making independent expenditures to support or oppose other candidates. 4. Must a committee file a Supplemental Independent Expenditure Report (Form 465) if an independent expenditure supports or opposes multiple ballot measures? A: Yes, but only if $1,000 or more was expended to support or oppose each ballot measure in the independent expenditure. A separate Form 465 must be filed for each measure supported or opposed. FPPC Toll -Free Helpline: 1 -866 -ASK FPPC 10107 Attachment 17 Lands of Nicholson Pathway Project APN 336-42-021 Town of Los Altos Hills Biological Report Proposed bridge loation over Hale, Creek Biotic Resources Group Biotic Assessments Resource Management ♦ Permitting _Biotic Resources Group Biotic Assessments ♦ Resource Management ♦ Permitting Lands of Nicholson Pathway Project APN 336-42-021 Town of Los Altos Hills Biological Report Prepared for The Nicholson Company 1680 -Dell Avenue Campbell; CA 95008 Attn: Bob Dwyer Prepared by Biotic Resources Group Kathleen Lyons, Plant Ecologist With Dana Bland .& Associates Dana Bland, Wildlife Biologist January 5, 1010 2551 S. Rodeo Gulch Road #12 ♦ Soquel, California 95073 (831) 476-4803 ♦ brg@cruzio.com NICHOLSON PROPERTY PATHWAY PROJECT TOWN OF LOS ALTOS HILLS, CALIFORNIA BIOLOGICAL REPORT INTRODUCTION The Nicholson Property Pathway Project is located within the Town of Los Altos Hills, California. The site is located west of Interstate 280, northwest of Magdalena Avenue (Figure 1). The project is the construction of a multi -use recreational pathway within a 25 -foot wide pathway and utility easement (Tentative Parcel Map, Lea & Braze Engineering, Inc., 11-10-09). The majority of the pathway is proposed within or adjacent to existing roadways. The pathway will utilize areas within or adjacent to a paved extension of Eastbrooke Avenue and a dirt farm road that parallels the Highway 280 Caltrans right-of-way. The pathway project also includes a bridge over Hale Creek. A reconnaissance -level assessment of the biotic resources of the proposed pathway project area was conducted in December 2009. Specific tasks conducted for this study include: ♦ Characterize the major plant communities within the pathway work area; ♦ Identify potential sensitive biotic resources, including plant and wildlife species of concern within the proposed pathway work area, ♦ Evaluate the potential effects of the proposed pathway work on sensitive biotic resources and recommend measures to avoid or reduce such impacts. Nicholson Property Pathway Project I January 5, 1010 Biological Report Ts - 1 ,e, 0" W 122°0700 t. 122-06-00' W WGS84 1 tlWlt �000wy C-- '_0OMItIBS Punted from TOPOt 02001 NetvW 0eoMphr Hokbra (www tom mm) Figure 1. Project Location, USGS Cupertino Quadrangle Nicholson Property Pathway Project Biological Report 2 January 5, 2010 Z EXISTING BIOTIC RESOURCES METHODOLOGY The biotic resources of the Nicholson Property Pathway project site were assessed through reconnaissance - level field observations on December 23, 2009. The proposed pathway route was walked. The plant communities along the pathway route were identified during the field reconnaissance visit. To assess the potential occurrence of special status biotic resources, two electronic databases were accessed to determine recorded occurrences of sensitive plant communities and sensitive species. Information was obtained from the California Native Plant Society's (CNPS) Electronic Inventory (2009) and California Department of Fish & Game's (CDFG) RareFind database (CDFG, 2009) for the U.S.G.S. Cupertino quadrangle and surrounding quadrangles. This report summarizes the findings of the reconnaissance -level biotic assessment. The potential impacts of the proposed pathway on sensitive resources are discussed below. Measures to reduce significant impacts to a level of insignificance are recommended, as applicable. EXISTING BIOTIC RESOURCES Three plant community types were observed within the pathway easement area: willow riparian woodland, oak woodland, and ruderal (weedy) vegetation. Willow Riparian Woodland The riparian woodland is limited to the Hale Creek corridor. The creek bisects the property before entering a culvert within the Caltrans right-of-way and travelling northward under Highway 280. Hale Creek, a tributary to Permanente Creek, has intermittent flow within the Nicholson property. The channel had no surface flow during the December 2009 site visit. The vegetation along the creek is dominated by willows (Salix spp.), however; little riparian vegetation is present at the proposed bridge site (Figure 2). The vegetation at the proposed bridge site is limited to a patch of spreading rush (Juncus patens) and non-native poison hemlock (Conium maculatum). A young willow sapling grows upstream of the proposed crossing site; a patch of cattails (Typha sp.) grows near the inlet to the Caltrans culvert (Figure 3). Shrubs of coyote brush (Baccharis pilularis) grow downstream of the bridge site and on the northwestern slope, intermixing with non-native teasel (Dipsacus sativus), poison hemlock, and yellow star thistle (Centaurea solstitialis). No surface water was observed within the creek during the December field survey. The Ordinary High Water (OHW) line is approximately 2 inches above the thalweg (i.e., lowest point of channel), based on field observations of shelving and vegetation patterns. The channel width averages 1.5 feet. Although riparian habitat is generally one of the highest value habitats for wildlife, this portion of the riparian area along Hale Creek is of lower value to wildlife because of its relatively narrow width, discontinuous cover, and the close proximity of Highway 280. Common wildlife species that may utilize the riparian habitat within the project vicinity are those that can tolerate the nearby disturbances, such as Pacific treefrog (Hyla regilla), Anna's hummingbird (Calypte anna), black phoebe (Sayornis nigricans), Nicholson Property Pathway Project 3 January 5, 2010 Biological Report A 1 • western scrub jay (Aphelocoma californica), chestnut -backed chickadee (Poecile rufescens), and raccoon (Procyon lotor). iF ' `•Sly- "]J�_ it >1�► �'.' 1 Figure 2. Project area, showing proposed bridge over Hale Creek and extent of oak woodland. Figure 3. Hale Creek, at proposed bridge crossing. Nicholson Property Pathway Project 4 January 5, 2010 Biological Report Oak Woodland A portion of the pathway will be within oak woodland. As depicted in Figure 2, the oak woodland parallels Highway 280 and non-native landscaping within the Caltrans right -of way. The woodland supports mature trees of coast live oak (Quercus agrifolia), valley oak (Quercus lobata), California buckeye (Aesculus californica), California bay (Umbellularia californica). and blue elderberry (Sambucus mexicana). The understory is dense with shrubs and herbs, including poison oak (Toxicodendron diversilobum), California rose (Rosa californica), toyon (Heteromeles arbutifolia), coyote brush, miners lettuce (Montia sp.), and chickweed (Stellaria media). Invasive, non-native plant species are also present, such as poison hemlock, milk thistle (Silybum marianum), and Italian thistle (Carduus pycnocephalus). Figure 4 displays the condition of the oak woodland as well as non-native Eucalyptus trees within the Caltrans right-of-way. The wildlife value of oak woodland varies with the degree of canopy cover and the density and diversity of understory plants. Acorns from oaks provide an important food resource for many wildlife species, and natural cavities in the oaks provide nesting opportunities for some birds and mammals. Snags are an important component of oak woodlands to some wildlife such as woodpeckers, which excavate nests in snags and holes for storing acorns. Downed decaying logs and limbs add to the structural complexity of the habitat, and are important cover, nesting, roosting, and foraging substrate for species such as newts which are attracted to the moist microclimate and invertebrate food supply. The denser oak woodlands also provide escape cover during the day for species such as deer. Common wildlife species that may utilize the oak woodlands at the project site include California slender salamander (Batrachoseps attenuatus), western fence lizard (Sceloporus occidentalis), western scrub jay (Aphelocoma californica), California quail (Callipepla calfornica), red-tailed hawk (Buteo jamaicensis), California myotis (Myotis californicus), western gray squirrel (Sciurus griseus), and black -tailed deer (Odocoileus hemionus). Eucalyptus Oak Woodland ,, �. �, '; trees within s ' h Caltrans ROW E Proposed Pathway on Dirt Road Figure 4. Habitat conditions within oak woodland near Highway 280. Nicholson Property Pathway Project 5 January 5, 2010 Biological Report I io Ruderal Open areas and areas adjacent to roadways are dominated by ruderal (weedy, non-native) plant species. Plants typical of previously disturbed conditions are prevalent. Dominant species observed during the December site visit include wild oat (Avena fatua), wild mustard (Brassica rapa), yellow star thistle, bristly ox -tongue (Picris echioides), milk thistle, dandelion (Taraxacum officinale) and patches of coyote brush. The seeds of the ruderal plants may provide additional forage for some wildlife species, such as California towhee (Pipilo crissalis) and house finch (Carpodacus mexicanus). The predominance of non-native plants makes this habitat of low value to native wildlife. SENSITIVE BIOTIC RESOURCES Sensitive Habitats Sensitive habitats are defined by local, State, or Federal agencies as those habitats that support special status species, provide important habitat values for wildlife, represent areas of unusual or regionally restricted habitat types, and/or provide high biological diversity. Riparian habitat along Hale Creek is considered sensitive due to its importance to wildlife and is recognized as such by state/federal resource agencies and the Town of Los Altos Hills. Activities within the creek channel (within OHW), including in -stream wetlands, are regulated by the Army Corps of Engineers under Section 404 of the Clean Water Act. The CDFG also regulates activities along watercourses under Fish and Game Code 1602. Alterations to the bed and bank of a watercourse, including removal of riparian vegetation or work over a channel (i.e., spanning bridge), require consultation with CDFG and issuance of a Streambed Alteration Agreement (SAA) prior to construction. The proposed pathway project includes a free -span bridge over Hale Creek. An existing open area along the creek will be used for the crossing and although no riparian vegetation will be impacted, the work is expected to require a SAA from CDFG. No work will occur within the OHW of the creek, and thus no 404 permit would be required. Oak woodlands are also sensitive habitat. This community is designated as a high priority for preservation by CDFG and the state has developed policies to minimize impacts to oak woodland resources, including requirements for tree replacement. The proposed project includes a pathway that will traverse oak woodland. The pathway will utilize an existing dirt farm road and no tree removal is expected, although tree limbs may be trimmed to provide trail clearances. Special Status Plant Species Plant species of concern include those listed by either the Federal or State resource agencies as well as those identified as rare by CNPS. Based on a search of the CNPS and CNDDB inventories for the Cupertino and surrounding quadrangles and visual observations of the project site, the potential for plant species of concern is considered low. This evaluation is based on the lack of suitable habitat for sensitive plant species (e.g., lack of serpentine grassland, coastal prairie, chaparral, and vernal pools). No special status species were observed within the project area during the December survey; however this survey was conducted Nicholson Property Pathway Project 6 January 5, 2010 Biological Report ;t it during the non -blooming period of most plant species. However, no special status plant species are expected to occur on the site based on an evaluation of the sites habitat features. Special Status Wildlife Species Special status wildlife species include those listed by either the Federal or State resource agencies as well as those identified as Federal and/or State species of special concern. In addition, all raptor nests are protected by Fish and Game Code, and all migratory bird nests are protected by the Federal Migratory Bird Treaty Act. A few special status wildlife species are listed in the CNDDB within the general project vicinity but are not expected to occur at the Hale Creek trail and bridge crossing site as explained below. The California tiger salamander (Amhystoma californiense) requires grasslands with burrows and ponds for breeding; neither of these habitat types are present within or nearby the project site. The California red -legged frog (Rana aurora draytonii) requires ponded or slow moving water for breeding and emergent or overhanging vegetation for cover; neither of these habitats types are present within or near the project site. The closest California red -legged frog occurrence listed in the CNDDB is along Permanente Creek, approximately 3 miles from this site (CDFG 2009). The project site lacks suitable breeding habitat for this species due to the ephemeral nature of this portion of the creek and limited cover vegetation; the species is not expected to occur at the pathway project site. The western burrowing owl (Athene cunicularia hypugea) requires extensive grasslands for foraging and burrows for cover and nesting; this habitat type does not occur within the project area. The pallid bat (Antrozous pallidus) roosts in large crevices in rocks and trees and is very sensitive to disturbance; there is no suitable roosting habitat for this bat on the project site. The Cooper's hawk (Accipiter cooperii) is a State species of special concern. Cooper's hawks prefer forested habitats in mountainous regions, but also use riparian woodlands. Cooper's hawks build stick nests in the tree canopy. The local breeding season probably spans March/April through July (Suddjian 1990). Cooper's hawks are uncommon migrants and winter visitors. Migrant and wintering individuals occur in a variety of habitats, including oak woodland, conifer and mixed broadleaf forests, grasslands, residential areas and riparian woodland. Habitat destruction and falconry practices have been attributed to this species' decline in California (Remsen 1978). The oak woodland at the project site provides marginal but potentially suitable nesting habitat for Cooper's hawk. San Francisco dusky -footed woodrat (Neotoma fuscipes annectens) is a State species of special concern. . These small mammals build large stick nests at the bases of trees and shrubs. They prefer forested habitat with a moderate canopy and brushy understory, and are often found on the upper banks of riparian forests. This woodrat feeds on a variety of woody plants, fungi, flowers and seeds (Jameson and Peeters 1988). The oak woodland at the project site provides suitable habitat for woodrats; however, no woodrat nests were observed within or adjacent to the project work area. Nicholson Property Pathway Project 1 January 5, 2010 Biological Report U 0 IMPACT AND MITIGATION DISCUSSION IMPACT CRITERIA The thresholds of significance presented in Appendix G of the CEQA "Guidelines were used to evaluate project impacts and to determine if implementation of the proposed project would pose significant impacts to biological resources. For this analysis, significant impacts are those that substantially affect, either directly or through habitat modifications: • A species identified as a candidate, sensitive, or special status species in local or regional plans, policies, or regulations, or by CDFG or USFWS; • Federally protected wetlands as defined by Section 404 of the Clean Water Act (including, but not limited to, marsh, vernal pool, coastal marsh, etc.) through direct removal, filling, hydrological interruption, or other means; • Interfere substantially with the movement of any native resident or migratory fish or wildlife species or with established native resident or migratory wildlife corridors, or impede the use of native wildlife nursery sites; • Conflict with any local policies or ordinances protecting biological resources, such as a tree preservation policy or ordinance; • Conflict with the provisions of an adopted Habitat Conservation plan, Natural Community Conservation plan, or other approved local, regional, or state habitat conservation plan. POTENTIAL IMPACTS AND RECOMMENDED MITIGATION MEASURES The proposed pathway project was evaluated as to potential impacts to biological resources. As depicted on the Tentative Map, the pathway will be placed on or adjacent to existing roads. The majority of the pathway will occur within or adjacent to common ruderal (weedy) vegetation. Impacts to ruderal vegetation are not considered significant as it is a vegetation community/habitat that is not protected, is generally common, and does not support special status species. Within the oak woodland, the pathway will utilize an existing dirt road; no trees will be removed, however, some tree limbs may be limbed to meet trail clearance requirements. Birds may nest in trees within the oak woodland portion of the site. No direct impact to nesting birds is expected because no trees will be removed for this project, however; construction noise and dust may affect nesting birds if they are present. A pathway -bridge will be placed over Hale Creek; all bridge construction (including construction access) will be outside of the creek channel. No riparian vegetation will be removed or otherwise affected (i.e., trimmed or trampled). Bridge supports will be placed on the top of bank. Bridge construction activities may result in indirect impacts to the creek, including downstream resources if construction materials or equipment inadvertently enter the creek or erosion and sediment enter the stream channel during or after construction. Such indirect impacts could result in significant impacts to biological resources. The following measures are recommended to avoid or minimize impacts to biological resources to a less than significant level: Nicholson Property Pathway Project 8 January 5, 2010 Biological Report 4 t Measure 1: Prior to construction, the applicant shall secure all necessary permits from regulatory agencies. This is expected to be a 1602 Streambed Alteration Agreement from CDFG. The project shall be implemented when the creek is dry and shall incorporate erosion control measures to avoid/minimize erosion or sediments from entering downstream aquatic resources during and after construction (i.e., use of silt fencing and/or other approved erosion control features). Measure 2. To avoid impacts to trees that are located adjacent to pathway construction the applicant shall implement tree protection measures as depicted on Sheet C-3 the Tentative Parcel Map. These measures include fencing erected along the dripline of retained trees (or tree groupings). Where fencing of the dripline is not feasible (such as along the existing dirt road), protection fencing shall be placed as far outward from the tree trunk as possible. All construction activities, including storage of construction materials and deposition of trash shall be prohibited from the fenced areas. The integrity of the fencing should be checked periodically and repaired if damage is noted. Where excavation is to occur within the dripline of existing trees, the applicant shall hand cut all tree roots greater than 3 inches in diameter. Limb removal shall follow Tree Pruning BMP's as adopted by the International Society of Arboriculture (ISA). Measure 3. To avoid indirect impacts to nesting birds, bridge construction and pathway construction within the oak woodland shall be scheduled between September 1 and March 1 of any given year. If this schedule is not practical and construction activities must occur during the bird nesting season, a qualified biologist shall conduct a focused survey for nesting birds no more than 15 days prior to construction. If any active bird nests are observed in the work area, the biologist will establish a buffer zone around the nest, wherein work within the buffer zone is postponed until the biologist has determined that all chicks have fledged. Nicholson Property Pathway Project Biological Report January 5, 2010 M 11 4 LITERATURE CITED AND REFERENCES California, State of, Department of Fish & Game. 2009. Natural Diversity Data Base, Natural Communities. 2009 RareFind program. Hayes, M. P. and M. R Jennings. 1988. Habitat correlates of distribution of the California red -legged frog (Rana aurora draytoni) and the foothill yellow -legged frog (Rana boylii): Implications for management. In Management of amphibians, reptiles, and small mammals in North America (R. C. Szaro, K. E. Severson, and D. R. Patton, tech. coord.). USDA, Forest Serv., Rocky Mountain Forest and Range Experiment Sta. Gen. Tech. Rpt. RM -166. Hickman, J. 1993. The Jepson Manual Higher Plants of California. Berkeley: University of California Press. Holland, R.F. 1986. Preliminary Descriptions of the Terrestrial Natural Communities of California. CDFG Unpublished report, October 1986. Jameson, E. W. and H. J. Peeters. 1988. California mammals. Univ. of California Press, Berkeley. Remsen, J. V., Jr. 1978. Bird species of special concern in California. Calif. Dept. Fish and Game Report No. 78-1. Suddjian, D. L. 1990. Santa Cruz County breeding bird atlas project: Atlasser's assistant. Santa Cruz Bird Club, Santa Cruz, CA. Nicholson Property Pathway Project 10 January 5, 2010 Biological Report 11623 Rebecca Lane Los Altos Hills, Ca. 94024 Feb 10, 2010 Attachment 18 RECEIVED To: Los Altos Hills Subdivision Committee FEB 12 2010 Reference: Lands of Nicholson, Los Altos Hills TOWN OF LOS ALTOS HILLS Dear Committee Members, We are very concerned about the impact that development of the Lands of Nicholson will have on our property and on our privacy. We ask that members of the Subdivision Committee give consideration to our comments. Our property, purchased in 1979, shares a common East to West border on the South side of the Nicholson property. That property was under the Williamson Act as we worked through the planning process to build our home. We were told by Los Altos Hills town officials that it would not be developed for various reasons even when no longer held under the Williamson Act. Town officials who voiced these comments to us included: 1. Robert Crowe, City Manager 2. Joseph Dochnahl, Planning Commissioner 3. Mr. Carlsen, (?) Town Engineer 4. Paul Novack Associates, Civil Engineers who were engaged by the Damavandi developer 5. Curtis Williams, a later Director of the Planning Commission The assurance of no future development was given to others who purchased lots along the South border of the applicants property, including then City Manager Robert Crowe, his brother David Crowe, and future Planning Commissioner Louis Yanez. Current residents Karen and Harry Emerzian (650-941-8884) and Jenny and Preston Chan (510-482-0485) have also confirmed the assurance of no future development. The previous Planning Commissions and Town Councils had held strong views about what to do about this property and did not want to subdivide. Confident of maintaining privacy, we employed an architect who designed our home with extensive use. of glass and openness, oriented to the Northeast to give the feeling of being both outdoors and indoors. Our North and East walls consist of a 16 foot greenhouse window in our master bedroom, a 13 foot greenhouse window in the kitchen, 6 French doors primarily of glass in the family room and 16 other windows of various sizes in our living and dining rooms. Almost 50% of our total floor space is oriented to open views and space to the North and East, where the proposed development of the Nicholson land is located. This development of the Nicholson property is a threat to our privacy as well as to our views of the Valley and the mountains to the East. The applicants proposed structure on site A is a large 7000 sq/ft multi -storied construction oriented toward the West and whose height will rise high above our existing fence and shrubbery. This will enable the residents to see into our master bedroom, kitchen, family room, living room and dining room. We want the right to maintain privacy as before. For 31 years we have paid Los Altos Hills (LAH) our property taxes and now we need LAH to recognize us and protect our property. We request that the Subdivision Committee consider the previous concerns voiced by the Town's staff in 1979 and their intent not to develop this property. And we ask that you address the open space situation. Every year less open space is available. LAH was created years ago by a group of people who wished to live in a area free of commercial business and provide a rural atmosphere in which to live. This proved to be very successful as LAH became a desirable area that attracts many people. The early Town planners had strong ideas about habitation and it is as valid today as they were then. Because of this we request that the Subdivision Committee deny the development of the lands of Nicholson.- There icholson: There is a precedent for the Subdivision Committee in this matter. A few years ago, Sprint Communications was installing their communication system along freeway 280. They erected a dummy antenna on the California Water pumping station site which abuts the eastern boundary of the lands of Nicholson with the antenna oriented straight into our home. We appealed to the Planning Commission to deny their request. Shelly Doran, Chairperson at the time, said to the Sprint team, " I know you need antennas, but do you have to point them into people's bedrooms?" Sprint did not get site approval. We appreciate your consideration of our request to study this development as proposed for the Lands of Nicholson and to allow us to retain the privacy that we were promised by the town of Los Altos Hills when we built our home. Respectfull , 1� r`7. . Donald and Janet Lull