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HomeMy WebLinkAboutPA2023-0161_20231013_CDD_Action LetterCommunity Development Department CITY OF NEWPORT BEACH 100 Civic Center Drive Newport Beach, California 92660 949 644-3200 newportbeachca.gov/communitydevelopment VIA EMAIL October 13, 2023 CAA Planning Attn: Pua Whitford 30900 Rancho Viejo Rd Unit 285 San Juan Capistrano, CA 92675 pwhitford@caaplanning.com Subject: Staff Approval Park Newport Bluff Stabilization Project (PA2023-0161) 5000 Park Newport Drive Dear Ms. Whitford, It was a pleasure working with you on the above referenced application. Please be advised that the subject application was approved by the Community Development Director on October 13, 2023 and effective on October 27, 2023. A copy of the approved action letter with findings and conditions is attached. If you have any questions, please do not hesitate to contact me directly. Thank you and I look forward to working with you again in the future. Sincerely, Liz Westmoreland, Senior Planner BMZ/law COMMUNITY DEVELOPMENT DEPARTMENT PLANNING DIVISION 100 Civic Center Drive, P.O. Box 1768, Newport Beach, CA 92658-8915 949-644-3200 www.newportbeachca.gov COMMUNITY DEVELOPMENT DIRECTOR ACTION LETTER Subject: Park Newport Bluff Stabilization Project (PA2023-0161) ▪ Staff Approval for Substantial Conformance Site Location: 5000 Park Newport Drive Applicant: Pua Whitford, CAA Planning Legal Description: Parcel 1 of Lot Line Adjustment No 94-01 On October 13, 2023, the Community Development Director approved the Staff Approval filed as PA2023-0161 allowing minor changes to an approved project and found said changes in substantial conformance with the Coastal Development Permit filed as PA2023- 0034. This determination is based on the following information and analysis and is subject to the Conditions of Approval thereafter. LAND USE AND ZONING • General Plan Land Use Plan Category: RM (Multiple Residential) • Zoning District: Planned Community 7- Park Newport (PC-7) • Coastal Land Use Plan Category: RM-D (Multiple Unit Residential) - (20.0 -29.9 DU/AC) • Coastal Zoning District: Planned Community 7 - Park Newport (PC-7) I. BACKGROUND There is an extensive history of slope failures at the subject property due to the location of the development (Park Newport Apartments) atop bluffs along Back Bay Drive. The most recent failure was a landslide in June of 2020. In response, the property owner retained licensed geotechnical engineering professionals to assess the risk of further slope failure and to assist with remediating the landslide area. Due to potential life safety and property risks, the owner received approval of emergency coastal development permits to temporarily install K-rail barriers along the toe of the slope adjacent to Back Bay Drive, anchored rockfall mesh at the head of the landslide area, and temporary tarps along selected portions of the property during the rainy season. The owner submitted a coastal development permit (CDP) requesting permanent authorization of the work as well as future installation of soldier piles to protect existing principal structures. Although the project was approved by the Planning Commission in April 2022, the project was appealed by a neighboring property owner to the California Coastal Commission. After the appellant’s concerns were resolved, the applicant consulted with the Park Newport Bluff Stabilization Project (PA2023-0161) October 13, 2023 Page 2 Tmplt: 07/25/19 California Coastal Commission to withdraw their application and apply for a new CDP with the City on February 7, 2023. On May 4, 2023, the Planning Commission approved a CDP to allow the installation of soldier piles, anchored mesh, temporary tarps, and k-rails to help prevent potential rockfall from the sloped area adjacent to the Park Newport Apartments. The Planning Commission also approved an encroachment permit and a waiver of Council Policy L-6 to allow for private encroachments on public property. However, the Encroachment Permit and Waiver of Council Policy L-6 are unrelated to the proposed minor changes to the approved Coastal Development Permit because no changes are proposed to the encroachment areas on public property (i.e., the K-rails at bottom of the slope). II. PROPOSED CHANGES Since gaining approval of the CDP, the property owner began refining the design of the authorized improvements and retained Langan Engineering and Environmental Services, Inc. (Langan) to prepare an additional geotechnical investigation. Langan’s findings are summarized in the report (Langan Report) dated August 17, 2023, and attached to this approval as Attachment No. CD 3. The Langan Report provides refined design parameters and recommends minor changes in the design and length of the soldier pile walls to ensure that the original intent of the approved CDP will be achieved. Consistent with the approved CDP, the proposed changes will occur below ground within the subject property. Figures 1 and 2 of the Langan Report illustrate the proposed changes compared to the approved CDP and are excerpted below. Figure 1 of the Langan Report, with the authorized work shown in orange and the proposed changes in blue. Park Newport Bluff Stabilization Project (PA2023-0161) October 13, 2023 Page 3 Tmplt: 07/25/19 Notably, the soldier pile wall near Building 4 is proposed to be approximately 300 feet long, whereas the original CDP contemplated a 200 foot-long-wall. The soldier pile wall would be realigned slightly but would not extend beyond the ornamental landscaping along the edge of the bluff. Figure 2 of the Langan Report, with the authorized work shown in orange and the proposed changes in blue. The proposed soldier pile wall near Building 37 would be approximately 150 feet long, consistent with the original CDP. The Langan Report recommends an additional 30-foot- long solider pile wall be installed near the adjacent Building 36. This small soldier pile wall would be located adjacent to the building, would not extend beyond the top of the bluff, and is necessary to protect the existing residential structures. It would further serve to provide additional lateral support due to the steep out-of-slope dipping condition at this location, which is a condition prone to sudden slippage. A final geotechnical report with detailed design plans and recommendations will be submitted to the Building Division during building permit plan check, as required by the conditions of approval. No changes are proposed to the approved K-rails at the toe of the bluff, anchored mesh, or temporary tarps. III. FINDINGS Per Section 21.54.070 (Changes to an Approved Coastal Development Permit) of the Newport Beach Municipal Code (NBMC), the Community Development Director (Director) may authorize minor changes to an approved site plan, architecture, or the nature of the approved use, without a public hearing, where the Director first finds that the changes: Park Newport Bluff Stabilization Project (PA2023-0161) October 13, 2023 Page 4 Tmplt: 07/25/19 Finding: A. Are consistent with all applicable provisions of this Implementation Plan. Facts in Support of Finding: 1. The project is located within the Planned Community 7 – Park Newport Zoning District and Coastal Zoning District, which allows for residential uses. The proposed minor change to the soldier pile walls would not impact the existing or proposed use of the site as a residential apartment complex. 2. Section 21.30.030(C)(3)(ii) (Protective Structures) of the NBMC allows construction of protective structures when designed to mitigate adverse impacts on local shoreline sand supply and existing structures that are “Threatened by natural hazards, provided that the protective structures are limited to the minimum required to protect the existing structure and located on private land, not State lands.” The Park Newport Apartments on the property were constructed in 1969, which predates the Coastal Act of 1976 and are considered existing structures located on private land. The proposed minor change is consistent with this provision. The approved Resolution (PC2023-021) is attached as Attachment No. CD 2 and details the facts pertaining to the threat of hazards at the site. The proposed minor change does not change the basis of those facts. 3. The Langan Report states that the additional 30-foot-long soldier pile wall proposed at Building 36 is necessary to protect the existing residential structures and provide lateral support due to the steep out-of-slope dipping condition that is prone to sudden slippage. This additional soldier pile wall will serve to further protect the existing residential structure from documented natural hazards. 4. Section 21.30.030(C)(3)(d) (Protective Structures) of the NBMC requires that protective devices, such as the proposed soldier piles, be designed and sited to: (1) be as far landward as possible and within private property; (2) eliminate or mitigate adverse impacts to coastal resources; (3) minimize alteration of natural processes; (4) provide for public access to State tidelands and recreational areas; and (5) minimize visual impacts and maximize the enjoyment of the natural shoreline environment. a. The proposed minor change includes slight realignment of the approved soldier pile walls, extensions of the walls, and one additional 30-foot-long wall near Building 36. The proposed soldier pile walls are still located as far landward as possible within the property. The proposed landslide mitigation would help prevent future adverse impacts to coastal access through landslides and rockfalls onto the Back Bay trail below. b. Several alternatives to address the geologic conditions and future mitigation efforts were evaluated in prior geotechnical reports and the prior report’s conclusions remain relevant. The prior report referenced in Resolution Park Newport Bluff Stabilization Project (PA2023-0161) October 13, 2023 Page 5 Tmplt: 07/25/19 PC2023-021 analyzed alternatives to the soldier piles such as re-grading the slopes to a stable slope ratio and a mechanical solution of installing tiebacks and grade beams. However, the report concluded that the soldier pile solution is the least environmentally damaging alternative because it would result in the least amount of disturbance to the coastal bluff and biological resources. It would also not be visible on the bluff face and would still achieve the minimum factor of safety for the residential structures. The report indicates that the soldier piles would not be visible for approximately 50 to 150 years, and only if the slope has eroded, retreated, or failed to the locations of the piles. The proposed minor change would not impact the conclusions of the prior alternatives analysis. 5. Section 21.30.100(E)(8) (Landform Alteration) of the NBMC requires that development be sited and designed to minimize removal of vegetation and the alteration of rock outcroppings and other natural landforms. The proposed minor changes would be consistent with the original CDP and would result in similar, minimal vegetation removal and the soldier piles would still remain landward of the bluff face. 6. The proposed soldier piles would be located below grade; therefore, no impacts to public views are anticipated as part of the minor changes. 7. The proposed minor changes are remaining consistent with the findings of approval for the previously approved CDP and the conditions of approval set forth by Resolution No. PC2023-021. Finding: B. Do not involve a feature of the project that was a basis for subject of findings or exemptions in a negative declaration or Environmental Impact Report for the project. Fact in Support of Finding: 1. The approved project was found to be categorically exempt from the requirements of CEQA pursuant to Section 15301 under Class 1 (Existing Facilities) and Section 15303 under Class 3 (New Construction or Conversion of Small Structures). The Class 1 exemption includes the operation, repair, maintenance, permitting, leasing, licensing, or minor alteration of existing public or private structures, facilities, mechanical equipment, or topographical features, involving negligible or no expansion of use. The Class 3 exemption includes the construction of new small facilities or structures such as utility improvements and residential accessory structures. The proposed minor changes do not involve a feature of the project that was a basis for the referenced exemptions and will not compromise the original categorical exemptions under the California Environmental Quality Act (CEQA) Guidelines. Park Newport Bluff Stabilization Project (PA2023-0161) October 13, 2023 Page 6 Tmplt: 07/25/19 Finding: C. Do not involve a feature of the project that was specifically addressed or was the subject of a condition(s) of approval for the project or that was a specific consideration by the applicable review authority in the project approval. Facts in Support of Finding: 1. The proposed minor changes do not involve a feature that was specifically addressed in the public hearing, resolution, or staff report prepared for the previous action reviewed under PA2023-0034. 2. The soldier pile walls are an approved component of the project, and the conditions of approval did not detail the allowed length or size of the soldier pile walls. Only conceptual plans were evaluated as part of the project, and the detailed design plans will be reviewed as part of the Building Permit process. 3. The project does not include any physical changes that would conflict with the existing CDP conditions of approval, as the plans are substantially conforming with the original CDP plans. Building permits are required for any construction at the project site and plans must comply with all conditions of approval of the Resolution No. PC2023-021. 4. The proposed minor changes have been reviewed by relevant departments including the Building Division. No additional conditions were required. Finding: D. Do not result in an expansion or change in operational characteristics of the use. Fact in Support of Finding: 1. The project site is located within the Park Newport Planned Community (PC-7). The proposed minor changes comply with all applicable residential development standards and would not result in an expansion or change in operational characteristics of the residential use of the site. The increased length of the proposed soldier pile walls will protect the existing residential use but would not change the operational characteristics or expand the use. Finding: E. Do not alter the facts in support of the findings required by Section 21.52.015 (F) and any other application section of this Implementation Plan. Park Newport Bluff Stabilization Project (PA2023-0161) October 13, 2023 Page 7 Tmplt: 07/25/19 Fact in Support of Finding: 1. As detailed under Finding A, the project would remain consistent with the Implementation Plan and the proposed minor changes to the soldier pile walls will not alter the facts in support of Findings for Resolution No. PC2023-021. The length and specific location of the soldier pile walls were not limited through specific facts in the approved CDP. The minor changes proposed represent the minimum necessary basis of design for the project to be implemented in a manner that upholds the spirit and intent of the original approval. IV. CONDITIONS OF APPROVAL All previous findings and conditions of approval of the Coastal Development Permit filed as PA2023-0034 shall remain in full force and effect, as included as Exhibit “A” to Resolution No. PC2023-021 and provided in Attachment No. CD 2. The following conditions are specific to this determination: 1. All applicable conditions of approval for Coastal Development Permit filed under PA2023-0034 shall remain in effect. 2. The development shall be in substantial conformance with Figures 1 and 2 of the attached Langan Memorandum dated August 17, 2023 (Attachment No. CD 3). 3. This approval does not relieve the applicant of compliance with other City or State requirements. A building permit shall be required for any improvements. 4. To the fullest extent permitted by law, applicant shall indemnify, defend and hold harmless City, its City Council, its boards and commissions, officials, officers, employees, and agents from and against any and all claims, demands, obligations, damages, actions, causes of action, suits, losses, judgments, fines, penalties, liabilities, costs and expenses (including without limitation, attorney’s fees, disbursements and court costs) of every kind and nature whatsoever which may arise from or in any manner relate (directly or indirectly) to City’s approval of the Park Newport Bluff Stabilization Project including, but not limited to, the Staff Approval filed under PA2023-0161. This indemnification shall include, but not be limited to, damages awarded against the City, if any, costs of suit, attorneys' fees, and other expenses incurred in connection with such claim, action, causes of action, suit or proceeding whether incurred by applicant, City, and/or the parties initiating or bringing such proceeding. The applicant shall indemnify the City for all of City's costs, attorneys' fees, and damages which City incurs in enforcing the indemnification provisions set forth in this condition. The applicant shall pay to the City upon demand any amount owed to the City pursuant to the indemnification requirements prescribed in this condition. APPEAL PERIOD: An appeal or call for review may be filed with the Director of Community Development or City Clerk, as applicable, within fourteen (14) days following the date the Park Newport Bluff Stabilization Project (PA2023-0161) October 13, 2023 Page 8 Tmplt: 07/25/19 action or decision was rendered. For additional information on filing an appeal, contact the Planning Division at 949 644-3200. Prepared by: _____________________________ Liz Westmoreland, Senior Planner Approved by: Assistant City Manager BMZ/law Attachments: CD 1 Vicinity Map CD 2 Resolution No. PC2023-021 CD 3 Langan Memorandum (August 17, 2023) Attachment No. CD 1 Vicinity Map Park Newport Bluff Stabilization Project (PA2023-0161) October 13, 2023 Page 2 Tmplt: 07/25/19 VICINITY MAP Staff Approval (PA2023-0161) Park Newport Bluff Stabilization Project 5000 Park Newport Subject Property Attachment No. CD 2 Resolution No. PC2023-021 RESOLUTION NO. PC2023-021 A RESOLUTION OF THE PLANNING COMMISSION OF THE CITY OF NEWPORT BEACH, CALIFORNIA, APPROVING A COASTAL DEVELOPMENT PERMIT TO ALLOW LANDSLIDE AND ROCK FALL MITIGATION AND A WAIVER OF CITY COUNCIL POLICY L-6 FOR A MULTI-UNIT APARTMENT COMPLEX LOCATED AT 5000 PARK NEWPORT DRIVE (PA2023-0034) THE PLANNING COMMISSION OF THE CITY OF NEWPORT BEACH HEREBY FINDS AS FOLLOWS: SECTION 1. STATEMENT OF FACTS. 1. An application was filed by Park Newport Land LTD, a California limited partnership (“Owner”), with respect to property located at 5000 Park Newport Drive, and legally described as Parcel 1 of Lot Line Adjustment No 94-01 recorded as Document # 94-0092253 in the office of the County Recorder of Orange County (“Property”), requesting approval of an encroachment permit and coastal development permit (“CDP”). 2. A landslide occurred at the Property on June 26, 2020, which resulted in the temporary closure of Back Bay Drive to vehicular traffic. 3. The Owner retained Hetherington Engineering, Inc. a professionally licensed engineering and geology firm (“Hetherington”), to assess the risk of further slope failure and assist with remediating the landslide area. On January 6, 2021, Hetherington issued a geotechnical opinion letter that concluded there is an imminent risk of future rockfalls at the Property due to a steeply inclined scarp along the upper portion of the landslide area. The letter recommended installation of an anchored rockfall mesh at the head of the scarp of the landslide area and k-rail barrier along the toe of the slope as soon as possible. 4. On January 20, 2021, the Owner submitted a request for an emergency CDP to install the measures identified in the Hetherington recommendation. Emergency CDP No. CD2021- 001 was subsequently approved by the Community Development Director on January 22, 2021. 5. Consistent with the Conditions of Approval for CD2021-001 and CD2021-066, the Owner submitted a request for a CDP on April 22, 2021, to permanently authorize the work completed under the two emergency CDPs. The CDP request included additional landslide mitigation consisting of the installation of soldier piles to protect two existing multi-unit residential structures based on the recommendation from Hetherington dated March 29, 2021. 6. On October 21, 2021, Hetherington issued a third geotechnical opinion letter that concluded there was an imminent risk of future landslides during significant rain events and recommended the immediate installation of temporary tarps along selected portions of the Property for the duration of the rainy season. Planning Commission Resolution No. PC2023-021 Page 2 of 16 01-17-23 7. Also on October 21, 2021, the Owner submitted a second emergency CDP request to install temporary tarps consistent with Hetherington’s recommendation. Emergency CDP No. CD2021-066 was approved by the Community Development Director on October 26, 2021. The previously submitted application for a CDP was updated to include a request for seasonal tarping every year during the rainy season. 8. The Property is bordered by public property along the Newport Beach Back Bay, including the Back Bay Drive public trail. The Owner requested approval to retain the existing non- compliant improvements within the public right-of-way, consisting of three sections of temporary k-rail that encroach up to 12 feet, 8 inches into the 40-foot-wide public right-of-way at the Property. The Back Bay Drive parkway within the public right-of-way varies in width from approximately eight feet to fifteen feet from edge of pavement to the subject property line. City Council Policy L-6 (“Policy L-6”) limits encroachments to a one foot projection into the right-of-way or less than 36 inches in height. 9. The requested encroachments were not specifically provided for within Policy L-6. Thus, the encroachment is prohibited under Section A (Private encroachments that are prohibited without a waiver and approval) of said Policy. Due to this prohibition, the requested encroachment could only be approved upon the waiver of Policy L-6 and approval of an encroachment permit by the Planning Commission. 10. A duly noticed public hearing was held on April 21, 2022, in the Council Chambers located at 100 Civic Center Drive, Newport Beach, California. A notice of time, place and purpose of the public hearing was given in accordance with the California Government Code Section 54950 et seq. (“Ralph M. Brown Act”) and Chapter 21.62 (Public Hearings) of the NBMC. Evidence, both written and oral, was presented to, and considered by, the Planning Commission at this public hearing. 11. At the conclusion of the public hearing, the Planning Commission unanimously approved the Project (7-0) in its entirety. No appeals were filed locally with the City of Newport Beach. 12. On May 11, 2022, Juliette and Todd Worthe (“Appellants”) filed a timely appeal of the Project with the California Coastal Commission (“CCC”). 13. On July 13, 2022, the CCC found substantial issue with the City’s approval. The CCC determined that the City’s conclusion that the development is consistent with the provisions of the LCP was not adequately supported by documents in the record file or the City’s findings. The Appellants’ concerns related only to aesthetic impacts to the bluff from the placement of tarps during the rainy season (October to April). 14. On October 11, 2022, Rock Solid Geotechnical issued a temporary tarp placement letter that concluded there is an imminent risk of impacts to Back Bay Drive and the public if the tarps are not installed prior to significant rainfall. 15. On October 14, 2022, the Owner requested an emergency CDP for seasonal tarping recommended by Rock Solid Geotechnical. The CCC supported the Owner’s request and on October 14, 2022, the Community Development Department Director approved the Planning Commission Resolution No. PC2023-021 Page 3 of 16 01-17-23 Emergency CDP filed as PA2022-0233. The tarps were installed on the bluff shortly thereafter to be removed at the end of the rainy season. 16. On February 7, 2023, the Owner consulted with the CCC to withdraw their application with the CCC and applied for a new CDP with the City. As part of this new application submittal, the Owner modified the request to reduce the visual impact of the seasonal tarps through use of clear tarps with burlap. Other modifications to the prior CDP request include installation of smaller piles (i.e., “micropiles”) and tieback anchors recommended by Rock Solid Geotechnical in their report dated January 25, 2023 (“Project”). The Project remains largely the same as the original project approved by the Planning Commission on April 21, 2022. 17. The Property is designated by the General Plan Land Use Element as RM (Multiple Residential) and is in the Planned Community 7-Park Newport Zoning District. 18. The Property is in the Coastal Zone. The Coastal Land Use Plan designation is RM-D (Multiple Unit Residential) - (20.0 -29.9 DU/AC) and it is located within the Planned Community 7 -Park Newport (PC-7) Coastal Zoning District. 19. A public hearing was held on May 4, 2023, in the Council Chambers located at 100 Civic Center Drive, Newport Beach, California. A notice of time, place and purpose of the public hearing was given in accordance with the Ralph M. Brown Act and Chapter 21.62 (Public Hearings) of the NBMC, and Council Policy L-6 (Encroachments in Public Rights-of- Way). Evidence, both written and oral, was presented to, and considered by, the Planning Commission at this public hearing. SECTION 2. CALIFORNIA ENVIRONMENTAL QUALITY ACT DETERMINATION. This Project is categorically exempt from the California Environmental Quality Act (“CEQA”) pursuant to Section 15269 (c) (the activity is necessary to prevent or mitigate an emergency), Section 15301 under Class 1 (Existing Facilities), and Section 15303 under Class 3 (New Construction or Conversion of Small Structures) of the CEQA Guidelines, California Code of Regulations, Title 14, Division 6, Chapter 3. Section 15269 allows specific actions necessary to prevent or mitigate an emergency. The Project is necessary to mitigate and reduce the immediate risks associated with rock, soil, or other debris from falling on to Back Bay Drive during a potential rain event. The Class 1 exemption includes the operation, repair, maintenance, permitting, leasing, licensing, or minor alteration of existing public or private structures, facilities, mechanical equipment, or topographical features, involving negligible or no expansion of use. The Class 3 exemption includes the construction of new small facilities or structures such as utility improvements and residential accessory structures. There are no known exceptions listed in CEQA Guidelines Section 15300.2 that would invalidate the use of these exemptions because the project is not located near a scenic highway, hazardous waste site, or historic resource and there are no other unusual circumstances or cumulative impacts related to the project. SECTION 3. REQUIRED FINDINGS. Planning Commission Resolution No. PC2023-021 Page 4 of 16 01-17-23 In accordance with Section 21.52.015 (Coastal Development Permits, Findings and Decision) of the NBMC, the following findings and facts in support of such findings are set forth: Finding: A. Conforms to all applicable sections of the certified Local Coastal Program. Facts in Support of Finding: 1. The Project complies with applicable residential development standards including, but not limited to, floor area limitation, setbacks, height, and parking. The Project includes retaining the existing steel mesh on the bluff face, the use of seasonal tarping, and the installation of micropiles (i.e., small soldier piles), which are underground structures. Minor grading and drainage are proposed along the top of the bluff to ensure that water drains away from the bluff face. None of the Project features would impact parking, height, setbacks, or floor area of the existing residential structures on site. 2. Section 21.52.025 (Emergency Coastal Development Permits) of the NBMC, allows for the issuance of emergency coastal development permits where, “[I]n the event of a verified emergency, temporary permits to proceed with remedial measures may be authorized by the Director until such time as a full coastal development permit shall be filed.” a. Based upon the January 6, 2021, and October 21, 2021, geotechnical opinion letters issued by Hetherington which concluded there is an imminent risk of future landslides without immediate mitigation, the Community Development Director verified that an emergency existed and authorized immediate action via emergency CDP Nos. CD2021-001 and CD2021-066 to prevent/mitigate loss or damage to life, health, property and essential public services. b. Based upon the October 11, 2022 temporary tarp placement letter prepared by Rock Solid Geotechnical, which concluded that there is an imminent risk of impacts to Back Bay Drive and the public if the tarps are not installed prior to significant rainfall, the Community Development Director verified that an emergency existed and authorized immediate action via emergency coastal development permit PA2022-0233 to prevent/mitigate loss or damage to life, health, property and essential services. 3. The emergency work was conducted to stabilize the surface as mitigation for the purposes of maintaining public safety and to prevent future closure of Back Bay Drive due to fallen debris. This will ensure continuity of public access to the public parking lot located on Back Bay Drive. 4. Section 21.30.030(C)(3)(ii) (Protective Structures) of the NBMC allows construction of protective structures when designed to mitigate adverse impacts on local shoreline sand supply and existing structures that are “Threatened by natural hazards, provided Planning Commission Resolution No. PC2023-021 Page 5 of 16 01-17-23 that the protective structures are limited to the minimum required to protect the existing structure and located on private land, not State lands.” a. The Park Newport Apartments on the Property were constructed in 1969, which predates the Coastal Act of 1976 and are considered existing structures located on private land. b. Based upon a history of six recorded landslides on the Property dating back to 1978 and existing slope conditions that are described by Hetherington as “grossly and surficially unstable from an engineering geologic and geotechnical engineering perspective,” two existing multi-unit residential structures (Building 4 & Unit 4830/Clubhouse) are threatened by landslide and require further mitigation in the form of soldier pile installation, in combination with the use of temporary tarping at select locations along the slope during the rainy season. c. A Geotechnical Summary of Proposed Landslide Mitigation was prepared by Rock Solid Geotechnical, dated January 25, 2023, to reevaluate Hetherington’s proposed solutions to protect the existing residential structures at the subject property. The report states that, due to the height, steep slope ratio, existing landslides, locally adverse geologic structure, and poor-quality bedrock exposed on the coastal bluff, the slope is considered grossly and surficially unstable from an engineering geologic and geotechnical engineering perspective. The report recommends mitigation in the form of extending the clubhouse soldier piles to the south and installing micropiles (small soldier piles) and tiebacks southeast of Building 4, which is substantially consistent with the Hetherington reports. 5. Section 21.30.030(C)(3)(d) (Protective Structures) of the NBMC requires that protective devices, such as the proposed micropiles, be designed and sited to: (1) be as far landward as possible and within private property; (2) eliminate or mitigate adverse impacts to coastal resources; (3) minimize alteration of natural processes; (4) provide for public access to State tidelands and recreational areas; and (5) minimize visual impacts and maximize the enjoyment of the natural shoreline environment. a. The proposed micropiles are located as far landward as possible within the Property. The landslide and rockfall mitigation measures would prevent future adverse impacts to coastal access through landslides and rockfalls onto the Back Bay trail. Lastly, as conditioned, the seasonal tarping would minimize visual impacts and retain the aesthetic qualities of the bluff by using tarps that blend into the landscape. b. Several alternatives to address the geologic conditions and future mitigation efforts were evaluated by Hetherington in a report dated April 21, 2022. The report analyzes alternatives to the soldier piles such as re-grading the slopes to a stable slope ratio and a mechanical solution of installing tiebacks and grade beams. However, the report concludes that the soldier pile solution is Planning Commission Resolution No. PC2023-021 Page 6 of 16 01-17-23 the least environmentally damaging alternative because it would result in the least amount of disturbance to the coastal bluff and biological resources. It would further not be visible on the bluff face and would still achieve the minimum factor of safety for the residential structures. The report indicates that the soldier piles would not be visible for approximately 50 to 150 years, and only if the slope has eroded, retreated, or failed to the locations of the piles. c. An additional alternative was evaluated in a memorandum prepared by Kane Geotech Inc., dated April 5, 2023. The memorandum evaluated retrofitting piles underneath the existing structures (i.e., underpinning) and low impact solutions such as soil nails with high strength steel mesh and erosion control matting. However, the report concluded that the retrofitting of piles was deemed to be overly complex, incur a high risk of damaging the existing structures, risked public safety, and would be cost inefficient compared with other stabilization measures. The soil nails and steel mesh and erosion control matting were unviable due to property limits and construction restrictions on the slope. Therefore, both Hetherington and Kane Geotech Inc. have indicated that the proposed soldier or micropiles are the least damaging environmental alternative that would provide protection to the existing residential structures. 6. The location on the Property is a coastal bluff that is identified as an Environmentally Sensitive Habitat Area (“ESHA”). Section 21.30B.060(A) (Mitigation and Monitoring) of the NBMC requires mitigation and monitoring programs including restoration and management programs in conjunction with coastal development permits in ESHA areas. a. The Property is located within the Orange County Central Coastal Natural Communities Conservation Plan (“NCCP”). Therefore, in accordance with the NCCP Construction Measures requirements, surveys were conducted on-site prior to installation of the metal mesh. A technical memorandum was prepared by Glen Lukos Associates (“Glen Lukos”) dated February 17, 2021, to document the findings of a pre-construction survey for the federally-listed coastal California gnatcatcher and coastal cactus wren. The survey concluded that the project area subject to repairs contained no coastal sage scrub or cactus wren habitat and no coastal California gnatcatchers or cactus wren were detected. Nonetheless, a pre-construction survey was recommended for future construction on the site. b. A second technical memorandum was prepared by Glen Lukos, dated April 19, 2021, to evaluate potential impacts related to the proposed soldier pile construction. Based on Glen Lukos’ review, the project would not impact native habitats. Nonetheless, to comply with the NCCP Construction Minimization Measures, pre-construction surveys were recommended to ensure protection of the California Gnatcatcher and coastal cactus wren. Condition of Approval 10 is included to require the recommended pre-construction surveys. Planning Commission Resolution No. PC2023-021 Page 7 of 16 01-17-23 c. Impacts from the proposed seasonal tarping were evaluated by Glen Lukos in a technical memorandum dated August 26, 2022. The report concluded that the areas of tarping are steep, lack topsoil, and are highly erosive. The tarping locations are unvegetated with small exceptions that, as conditioned, would be cut out from the tarps during installation. The tarps would be installed and removed each rainy season in a manner that does not encroach into adjacent native vegetation. The report also concludes that the slope areas receiving seasonal protection from installation of the tarps are not expected to support vegetation in the absence of the tarps and the slope protection does not appear to pose an adverse effect on vegetation on the steep barren slopes. Condition of Approval 9 is included to require that the tarps be installed and removed in compliance with the recommendations of the August 26, 2022 report. 7. Section 21.30.100(E)(8) (Landform Alteration) of the NBMC requires that development be sited and design to minimize removal of vegetation and the alteration of rock outcroppings and other natural landforms. a. The technical memoranda prepared by Glen Lukos Associates indicate that there is limited vegetation within the Project area due to the steep slope and erosion on the bluff face. The proposed seasonal tarping is required to install cut outs in the material to allow any small areas of remaining vegetation to grow. Additionally, the project includes revegetating areas of the slope with a native seed mix to encourage new vegetation growth. b. The Project includes the minimum mitigation necessary to stabilize the bluff. The bluff face would be altered temporarily during the seasonal tarping, which would not permanently impact the landform. The tarps have been conditioned to blend into the existing bluff face landform. The proposed micropiles are proposed in two locations that are directly adjacent to Building 4 and the Building 37 (Clubhouse)/Unit 4830. The micropiles are located as far landward as possible and according to Heatherington, would not be visible for at least 50 to 150 years should the bluff continue to erode. Lastly, the existing metal mesh system is necessary to protect the public on the Back Bay trail below from falling rocks and boulders. The metal mesh consists of approximately 3,000 square feet, which is a very small portion of the approximately 311,300-square-foot bluff face within the Property. The metal mesh allows the bluff face below to be visible through the holes in the mesh, offsetting the visual impact of the mesh. 8. The Property is in an area known for the potential of seismic activity and liquefaction. All projects are required to comply with the California Building Code (“CBC”) and Building Division standards and policies. Geotechnical investigations specifically addressing liquefaction are required to be reviewed and approved prior to the issuance of building permits. Permit issuance is also contingent on the inclusion of design mitigation identified in the investigations. Construction plans are reviewed for compliance with approved investigations and CBC prior to building permit issuance. Planning Commission Resolution No. PC2023-021 Page 8 of 16 01-17-23 9. The Project site is located adjacent to and immediately east of Back Bay Drive, which is a designated public view road in the Coastal Land Use Plan and offers public views of Upper Newport Bay. Site evaluation revealed that the proposed landslide/rockfall mitigation improvements will not affect the existing views afforded from Back Bay Drive as the Project improvements are located landward of Upper Newport Bay. In addition, tarping of the slope has been limited through conditions of approval to only allow minimum times of the year when heavy rains are likely to occur and pose the greatest risk of landslide/slope failure. Therefore, the Project does not have the potential to degrade the visual quality of the coastal zone or result in significant adverse impacts to public views. 10. Local Coastal Program Policy 4.4.1-1 requires new development to protect coastal views along the ocean, bay, harbor, coastal bluffs and other coastal resources. The proposed tarps and sandbags are the least visually and physically intrusive alternative that would provide protection to the bluff while also not permanently altering the bluff. a. The tarps are conditioned to be a clear visqueen (or similar plastic) material with burlap or jute covering to blend with the natural color of the bluff. Based on the provided visual impact analysis, the existing bluff scarps are evident from close and distant vantage points and the proposed tarping would cover the existing scarp footprints. The Project is also conditioned to restrict the anchoring sandbags to natural brown or tan colors as well (Condition of Approval 5). b. Proposed tarping would be limited to the areas shown in the approved plans, which includes three areas along the approximately 1,300-linear foot bluff face (133,300 square feet) within subject property. The proposed square footage of the tarps would be limited to approximately 28,500 square feet. c. The seasonal tarping component of this coastal development permit is valid for 10 years maximum from the effective date of this approval, so that new alternatives can be evaluated in the future based on current conditions and technologies that may be available. Finding: B. Conforms with the public access and public recreation policies of Chapter 3 of the Coastal Act if the project is located between the nearest public road and the sea or shoreline of any body of water located within the coastal zone. Fact in Support of Finding: 1. The Project site is not located between the nearest public road and the sea or shoreline. Section 21.30A.040 (Determination of Public Access/Recreation Impacts) of the NBMC requires that the provision of public access bear a reasonable relationship between the requirement and the Project’s impact and be proportional to the impact. In this case, the Project mitigates future landslide risk and protects Back Bay Drive, which serves as a popular public recreation amenity through its use as a cycling, walking and jogging route. Therefore, the Project does not involve a change in land use, density or intensity that will Planning Commission Resolution No. PC2023-021 Page 9 of 16 01-17-23 result in increased demand on public access and recreation opportunities. The existing k-rails to be maintained are located on public property but would not impact use of the existing Back Bay trail because the k-rails are located along the edge of the trail. Furthermore, the Project is designed and sited (appropriate height, setbacks, etc.) so as not to block or impede existing public access opportunities. In accordance with City Council Policy L-6 (Encroachments in the Public Rights-of-Way), the following findings and facts in support of such findings are set forth: Finding: C. The existing private improvements will not be a detriment to the health, safety and welfare of the public. Facts in Support of Finding: 1. The Project does not hinder the present or future use of the public right-of-way, including sidewalks, and there are no existing City utilities located within the encroachment area. 2. The Back Bay Drive parkway within the public right-of-way varies in width from approximately 8 feet to 15 feet wide of the overall 40-foot right-of-way width. The requested encroachments project up to 12-feet 8-inches into the parkway. 3. The Project does not diminish the rights of the public along the Back Bay Drive right-of- way. There are no sidewalks along Back Bay Drive adjacent to the Project and the City does not currently have plans to install sidewalks. 4. The Back Bay Drive parkway generally slopes upward toward private property. The top of slope is approximately 86 feet above the road surface of Back Bay Drive. 5. Approval would require the Owner to enter into an Encroachment Agreement to allow the existing improvements as requested, and any liability associated with the existing private improvements would be transferred to the Owner. Additionally, if the need for public improvements should arise in the future, Owner shall agree to remove all encroachments at no cost to the City. Finding: D. The individual circumstances applicable to this application and the existing encroachment are consistent with the public interest. Facts in Support of Finding: 1. The k-rail is necessary to minimize slope debris onto the roadway to maintain access along Back Bay Drive. The k-rail along Section 2 was installed in 2021 as part of Coastal Development Permit No. CD2021-001 for emergency slope repair and future slope stabilization measures. It is unclear when Section 1 and Section 3 were installed. Planning Commission Resolution No. PC2023-021 Page 10 of 16 01-17-23 2. The maximum height of proposed structures in the right-of-way will not exceed 36 inches in height above the adjacent pavement surface. Public views along the Back Bay Drive will remain unobstructed. 3. There are no existing City utilities within the encroachment area. SECTION 4. DECISION. NOW, THEREFORE, BE IT RESOLVED: 1. The Planning Commission of the City of Newport Beach hereby finds this Project is categorically exempt from the California Environmental Quality Act (“CEQA”) pursuant to Section 15301 and Section 15303 under Class 1 (Existing Facilities) and Class 3 (New Construction or Conversion of Small Structures) of the CEQA Guidelines, California Code of Regulations, Title 14, Division 6, Chapter 3, because it has no potential to have a significant effect on the environment. There are no known exceptions listed in CEQA Guidelines Section 15300.2 that would invalidate the use of these exemptions because the project is not located near a scenic highway, hazardous waste site, or historic resource and there are no other unusual circumstances or cumulative impacts related to the project. 2. The Planning Commission of the City of Newport Beach hereby approves the CDP filed as PA2023-0034, subject to the conditions outlined in Exhibit “A,” which is attached hereto and incorporated by reference. 3. This action shall become final and effective 14 days following the date this Resolution was adopted unless within such time an appeal or call for review is filed with the Community Development Director by the provisions of Title 21 Local Coastal Implementation Plan, of the Newport Beach Municipal Code. Final action taken by the City may be appealed to the Coastal Commission in compliance with Section 21.64.035 of the City’s certified LCP and Title 14 California Code of Regulations, Sections 13111 through 13120, and Section 30603 of the Coastal Act. PASSED, APPROVED, AND ADOPTED THIS 4TH DAY OF MAY, 2023. AYES: Barto, Ellmore, Harris, Klaustermeier, Langford, Lowrey, and Rosene NOES: None ABSTAIN: None ABSENT: None BY: _ _...._L __ ~--- Curtis Ellmore, Chair ~~~~ BY: ~ "'Z \..--.... --~--------Sar ah Klaustermeier, Secretary 01-17-23 Planning Commission Resolution No. PC2023-021 Page 11 of 16 Planning Commission Resolution No. PC2023-021 Page 12 of 16 01-17-23 EXHIBIT “A” CONDITIONS OF APPROVAL Planning Division 1. The development shall be in substantial conformance with the approved site plan stamped and dated with the date of this approval (except as modified by applicable conditions of approval). 2. The Project is subject to all applicable City ordinances, policies, and standards unless specifically waived or modified by the conditions of approval. 3. The Owner, or future owner, shall comply with all federal, state, and local laws. A material violation of any of those laws in connection with the use may be caused the revocation of this CDP. 4. Protective devices authorized under this Coastal Development Permit shall be removed to the maximum extent feasible, when the existing structures requiring protection are no longer present or if there is a major remodel negating the protection, whichever comes first. 5. Tarps shall be clear in color with burlap or jute materials on top of the entire extent of the tarp to blend in with the bluff face. Similar colored material (tan or buff) shall be used for the sandbags that secure the tarps. The use of bright contrasting colors such as orange, yellow, or black shall be prohibited. After installation of temporary tarping during the rainy season, the Planning Division shall conduct a site investigation of the tarps to confirm compliance with the allowed color and design of the tarps. 6. Temporary tarping shall be limited to the months of October to the end of April to coincide with Southern California’s rainy season, unless it is determined that the rainy season has shifted to a different timeframe. 7. All temporary tarping authorized by this permit shall be limited to a 10-year period that shall commence upon the effective date of this approval once all appeal periods have expired. 8. All temporary tarping shall be limited to the approximate locations on the approved plans. 9. All temporary tarping shall be installed and removed in a manner that avoids native vegetation. The tarps shall be installed to the edge of any vegetation or allow for “cut outs” where local patches of vegetation are avoided and protected in place. 10. Prior to the commencement of grading operations or other activities involving disturbances to coastal sage scrub (including installation of seasonal tarping), a survey shall be conducted to locate gnatcatchers and cactus wrens within 100 feet of the outer Planning Commission Resolution No. PC2023-021 Page 13 of 16 01-17-23 extent of projected soil disturbance activities, and the locations of any such species shall be clearly marked and identified on the construction/grading plans. 11. This approval does not authorize any new or existing improvements (including landscaping) on California Coastal Commission Permit Jurisdiction, State tidelands, or public beaches. Any improvements located on tidelands, submerged lands, and/or lands that may be subject to the public trust shall require a CDP approved by the CCC. 12. No demolition or construction materials, equipment debris, or waste, shall be placed or stored in a location that would enter sensitive habitat, receiving waters, or a storm drain or result in impacts to environmentally sensitive habitat areas, streams, the beach, wetlands or their buffers. No demolition or construction materials shall be stored on public property. 13. The Owner is responsible for compliance with the Migratory Bird Treaty Act (MBTA). In compliance with the MBTA, grading, brush removal, building demolition, tree trimming, and similar construction activities shall occur between August 16 and January 31, outside of the peak nesting period. If such activities must occur inside the peak nesting season from February 1 to August 15, compliance with the following is required to prevent the taking of native birds pursuant to MBTA: A. The construction area shall be inspected for active nests. If birds are observed flying from a nest or sitting on a nest, it can be assumed that the nest is active. Construction activity within 300 feet of an active nest shall be delayed until the nest is no longer active. Continue to observe the nest until the chicks have left the nest and activity is no longer observed. When the nest is no longer active, construction activity can continue in the nest area. B. It is a violation of state and federal law to kill or harm a native bird. To ensure compliance, consider hiring a biologist to assist with the survey for nesting birds, and to determine when it is safe to commence construction activities. If an active nest is found, one or two short follow-up surveys will be necessary to check on the nest and determine when the nest is no longer active. 14. This CDP may be modified or revoked by the Planning Commission should they determine that the proposed uses or conditions under which it is being operated or maintained are detrimental to the public health, welfare, or materially injurious to property or improvements in the vicinity or if the property is operated or maintained to constitute a public nuisance. 15. Any substantial change or other modification to the approved plans, shall require subsequent review by the Planning Division and, depending on the scope of the change, may require an amendment to this CDP or the processing of a new CDP. 16. A copy of the Resolution, including conditions of approval Exhibit “A” shall be incorporated into the Building Division and field sets of plans before issuance of the building permits. Planning Commission Resolution No. PC2023-021 Page 14 of 16 01-17-23 17. Prior to the issuance of a building permit, the applicant shall pay any unpaid administrative costs associated with the processing of this application to the Planning Division. 18. Prior to issuance of a building permit, a construction erosion control plan shall be provided. Best Management Practices (BMPs) and Good Housekeeping Practices (GHPs) shall be implemented before and throughout the duration of construction activity as designated in the construction erosion control plan. 19. All noise generated by the proposed use shall comply with the provisions of Chapter 10.26 and other applicable noise control requirements of the NBMC. The maximum noise shall be limited to no more than depicted below for the specified periods unless the ambient noise level is higher: Between the hours of 7 AM and 10 PM Between the hours of 10 PM and 7 AM Location Interior Exterior Interior Exterior Residential Property 45dBA 55dBA 40dBA 50dBA Residential Property located within 100 feet of a commercial property 45dBA 60dBA 45dBA 50dBA Mixed Use Property 45dBA 60dBA 45dBA 50dBA Commercial Property N/A 65dBA N/A 60dBA 20. Should the property be sold or otherwise come under different ownership, any future owners or assignees shall be notified of the conditions of this approval by either the current business owner, property owner or leasing agent. 21. Construction activities shall comply with Section 10.28.040 of the NBMC, which restricts hours of noise-generating construction activities that produce noise to between the hours of 7 a.m. and 6:30 p.m., Monday through Friday, and 8 a.m. and 6 p.m. on Saturday. Noise-generating construction activities are not allowed on Sundays or Holidays. 22. This approval shall expire and become void unless exercised within 24 months from the actual date of review authority approval, except where an extension of time is approved in compliance with the provisions of Title 21 (Local Coastal Program Implementation Plan) of the NBMC. 23. To the fullest extent permitted by law, the applicant shall indemnify, defend and hold harmless the City, its City Council, its boards and commissions, officials, officers, employees, and agents from and against any claims, demands, obligations, damages, actions, causes of action, suits, losses, judgments, fines, penalties, liabilities, costs, and expenses (including without limitation, attorney’s fees, disbursements, and court costs) of every kind and nature whatsoever which may arise from or in any manner relate (directly or indirectly) to City’s approval of Park Newport Landslide and Rock Fall Mitigation Project including, but not limited to PA2023-0034. This indemnification shall include, but not be limited to, damages awarded against the City, if any, costs of suit, attorney’s fees, and Planning Commission Resolution No. PC2023-021 Page 15 of 16 01-17-23 other expenses incurred in connection with such claim, action, causes of action, suit, or proceeding whether incurred by the applicant, City, and/or the parties initiating or bringing such proceeding. The applicant shall indemnify the City for all the City's costs, attorneys' fees, and damages that which City incurs in enforcing the indemnification provisions outlined in this condition. The applicant shall pay to the City upon demand any amount owed to the City under the indemnification requirements prescribed in this condition. Building Division 24. The Owner is required to obtain all applicable permits from the City’s Building Division and Fire Department. The construction plans must comply with the most recent, City-adopted version of the California Building Code. The construction plans must meet all applicable State Disabilities Access requirements as applicable. 25. Prior to the issuance of a building permit, the applicant shall submit a Soils and Geology Report to the Building Division for review. The contents of soils and geology report shall include but are not limited to static slope stability analysis, seismic slope stability analysis, lateral earth pressure analysis, minimum field exploration, laboratory testing, and design recommendations. The report shall comply with City Policy “Geotechnical Investigation” document. 26. Prior to the issuance of a building permit for the soldier piles, the project plans or reports shall indicate that the soldier piles and tieback anchors account for seismic and creep loads. 27. Prior to the issuance of a building permit, grading and drainage plans shall be provided to demonstrate that surface sheet flow will not go over the top of the bluff. The plans shall indicate any drainage control measures that are required to divert stormwater from draining over the slope. Public Works Department 28. The Owner shall obtain an “After the Fact” Encroachment Permit to allow three sections of k-rail that encroach up to 12 feet 8-inches into the Back Bay Drive public right-of-way with a waiver of City Council Policy L-6, Section A (Private Encroachments that are Prohibited Without a Waiver and Approval). 29. The Owner shall enter an encroachment agreement within one (1) calendar year upon receipt of approval, otherwise this approval shall automatically expire. 30. This Encroachment Permit allows three sections of K-rail that encroach up to 12 feet 8- inches into the Back Bay Drive public right-of-way with a waiver of City Council Policy L-6, Section A. Planning Commission Resolution No. PC2023-021 Page 16 of 16 01-17-23 31. Crash cushions shall be installed at the beginning of each k-rail section. The design shall be reviewed and approved by the Public Works Department prior to fabrication and installation. 32. The Owner shall immediately remove any slope debris from the roadway surface. 33. At least monthly, the Owner shall inspect the Project site and shall promptly remove debris behind and around the k-rail. 34. If the need for public improvements arises in the future, the Owner shall remove all encroachments at no cost to the City. Attachment No. CD 3 Langan Memorandum (August 17, 2023) Memorandum 18575 Jamboree Road, Suite 150 Irvine, CA 92612 T: 949.561.9200 F: 949.561.9201 To: Don Bragg and Lisa Congdon, The Prado Group CC: Kari Heavenrich and Brian Howe, Rockpoint From: Christopher J. Zadoorian Date: August 17, 2023 Re: Basis of Design and Associated Updates to Previously Approved Soldier Piles and Landslide Mitigation Measures Previous City of Newport Beach Approval CDP PA 2023-0034 Park Newport Apartment Complex 1 Park Newport Newport Beach, California Langan Project No.: 700128101 Langan Engineering and Environmental Services Inc. (LANGAN) is pleased to submit this memo summarizing our basis of design for installation of the soldier piles needed to protect existing, principal residential structures at the Park Newport Apartment Complex located on 1 Park Newport in Newport Beach, California. The site is located at the northwest corner of Jamboree Road and San Joaquin Hills Road and is bound on the north by Big Canyon Nature Park and on the west by Upper Newport Bay (aka Back Bay) and Back Bay Drive as shown on Figure 1. The site is situated on a coastal bluff that includes descending slopes up to approximately 90 feet in height with gradients commonly ranging from approximately ½:1 to 1½:1 (horizontal:vertical) and in some cases near vertical. The site was developed between 1969 and 1972 and includes large footprint apartment buildings and small footprint townhomes as shown on Figure 2. Since construction, several episodes of mitigation have been implemented to address slope failures primarily along the west and northwest descending slopes. We are currently performing a design-level geotechnical evaluation and will issue the results of our investigation in a report. In the interim, this memorandum summarizes recommended alignment of the soldier piles and conceptual design parameters. Soldier pile have previously been proposed and approved by the City of Newport Beach (CDP PA 2023-0034) along the westerly sides of Buildings 4 and 37. The mitigation structures described herein are substantially the same kind of soldier pile structures as summarized in and authorized by the previously approved CDP, but with nominal changes made to the precise locations and lengths of the installation. The intent of the soldier piles to protect the existing residential structures and account for applicable geotechnical and structural (including seismic) loads. To aid in our evaluation, you furnished us with reports of geotechnical investigation for our review prepared by several firms including LeRoy Crandall & Associates (LCA, 1968, 1969 and MEMO Basis of Design and Associated Updates to Previously Approved Soldier Piles and Landslide Mitigation Measures (City of Newport Beach CDP PA 2023) Park Newport Apartment Complex Langan Project No.: 700128101 August 17, 2023 Page 2 of 3 1979), Hetherington Engineering, Inc. (HEI, 2021) and Rock Solid (2022 and 2023). Pertinent borings from the prior investigations are presented in the attachment for reference. Building 4 Building 4 is a four-level building that includes three above-grade apartment levels and one partial subterranean parking level as shown on Figure 1. The foundation elements of Building 4 are present within the subterranean level and these elements provide critical axial and lateral support for the residential dwellings located in this building. Based on our review of as-built plans, the building is supported on shallow caissons that range from approximately six to 19 feet deep. Mapped landslides, zones of rockfall and/or other portions of excessively steep slope are present along the westerly side of the building as summarized in the prior geotechnical reports. Several exploration borings were performed along the westerly side of Building 4 as shown on Figure 1. Based on our review of the prior boring data, a shear zone (zone of slippage) was logged in prior Borings 2 through 4 at depths ranging from 24 to 37 feet below the ground surface level in the borings (LCA, 1979). Based on our review of the prior geotechnical reports, as-built foundation plans, existing conditions, and our independent site reconnaissance, it is our professional opinion that an approximately 300-foot-long solider pile installation is required to provide adequate lateral support for the existing building. The proposed location of the mitigation structure is shown on Figure 1. The rationale for the current recommended wall length is to provide support to the foundation elements of residential Building 4 within areas of observed distress and/or zones of slope instability. The proposed soldier piles may consist of 24- to 36-inch diameter cast-in-drilled hole (CIDH) shaft solider piles noting that permanent tie-back anchors may also be incorporated. We anticipate solider piles will range on the order of 30 to 60 feet deep and tie-back anchors to extend approximately 50 to 75 feet at a typical inclination of approximately 20 degrees from the horizontal. Solider piles and tie-back anchors will be located below ground. Building 36 / 37 Building 36 and 37 are two-level townhomes established at approximately the existing ground surface level. Based on our review of as-built plans, the building is supported on shallow spread and continuous footings. Mapped landslides and excessively steep slope are present along the westerly side of the building as summarized in the prior geotechnical reports. A temporary mitigation measure consisting of steel-link mesh was installed in response to a surficial landslide that occurred circa 2020. MEMO Basis of Design and Associated Updates to Previously Approved Soldier Piles and Landslide Mitigation Measures (City of Newport Beach CDP PA 2023) Park Newport Apartment Complex Langan Project No.: 700128101 August 17, 2023 Page 3 of 3 Prior Boring 5 (LCA, 1968) does not indicate shear zones but does show relatively steep out of slope bedding planes that appear to be consistent with the 2020 landslide. Based on our review of the prior geotechnical reports, as-built foundation plans, existing conditions, and our independent site reconnaissance, approximately 150 lineal feet of soldier pile are required to stabilize existing Building 37 and approximately 30 lineal feet of soldier piles are required to stabilize existing Building 36. The proposed locations of the soldier piles and related mitigations are shown on Figure 2. The rationale for the recommended soldier piles is to protect the existing residential structures and provide lateral support needed due to the steep out-of-slope dipping condition (that is prone to sudden slippage) specifically at the westerly corner of Building 36. Additionally, the westerly corner of existing Building 37 extends to within approximately 15 feet of the top (aka edge) of the slope and additional protection is required at this location as shown on Figure 2. The proposed mitigation may consist of 24- to 36-inch diameter cast-in-drilled hole (CIDH) shaft solider piles. We anticipate solider piles will range on the order of 60 feet in depth. While tie- back anchors may increase stability, they may not be needed at this location and for the purposes of this basis of design memo have been omitted as access for tie-back anchor installation will be challenging. The protective structures described in this memo are intended to provide the minimum measures required to protect the existing principal residential dwellings. Closing We appreciate the opportunity to provide professional services for you for this project. Please contact us with any questions of comments regarding the information presented herein. Enclosures: Figures 1 and 2 Appendix – Prior Pertinent Boring Logs C:\Users\CZadoorian\Desktop\Projects\Prado-Group-Park-Newport\Report\Basis-of-Design\700128101-geom-basis-of-design-081723.docx FIGURES 4 B-2 51 B-3 51 B-6 20 B-1 51 B-4 51 B-7 21 B-5 21 B-7 100 Filename: \\langan.com\data\IRV\data1\700128101\Project Data\_Discipline\Geotechnical\CAD\OLD VERSIONS\GEOTECHNICAL FIGURES - 7.28 for client.dwg Date: 8/15/2023 Time: 15:36 User: smikolajczyk Style Table: Langan.stb Layout: 11x17 L Bldg 4 Project No. Date Scale Drawn By 700128101 AUGUST 2023 AS SHOWN Figure No.Figure TitleProject ORANGE COUNTY CALIFORNIA 1 PARK NEWPORT NEWPORT BEACH PARK NEWPORT APARTMENT COMPLEX Langan Engineering and Environmental Services, Inc. © 2 0 2 0 L a n g a n 18575 Jamboree Road Suite 150 Irvine, CA 92612 T: 949.561.9200 F: 949.561.9201 www.langan.com CC 1 SOLDIER PILE WALL LOCATION BUILDING 4 LEGEND: PROPOSED SOLDIER PILE WALL (LANGAN, 2023) PROPOSED SOLDIER PILE WALL CURRENTLY PART OF CDP PA2023-0034 (KGI, 2023) EXISTING TENSION CRACKS IN BUILDING 4 FLOOR SLAB APPROXIMATE LOCATION OF SUBTERRANEAN LEVEL OF BUILDING 4 PRIOR BORING LOCATION AND DEPTH IN FEET (LEROY CRANDALL, 1979) PRIOR BORING LOCATION AND DEPTH IN FEET (LEROY CRANDALL, 1968) LANDSLIDE ZONE (ROCKSOLID, 2023) LANDSLIDE ZONE (LEROY CRANDALL, 1968) SURFICIAL FAILURES/ EROSION/ROCKFALL LANDSLIDE DIRECTION BUILDING NUMBERS 4 B-7 100 B-1 51 36 37 B-5 75 B-6 75 Filename: \\langan.com\data\IRV\data1\700128101\Project Data\_Discipline\Geotechnical\CAD\OLD VERSIONS\GEOTECHNICAL FIGURES - 7.28 for client.dwg Date: 8/15/2023 Time: 15:39 User: smikolajczyk Style Table: Langan.stb Layout: 11x17 L Bldg 37 Project No. Date Scale Drawn By 700128101 AUGUST 2023 AS SHOWN Figure No.Figure TitleProject ORANGE COUNTY CALIFORNIA 1 PARK NEWPORT NEWPORT BEACH PARK NEWPORT APARTMENT COMPLEX Langan Engineering and Environmental Services, Inc. © 2 0 2 0 L a n g a n 18575 Jamboree Road Suite 150 Irvine, CA 92612 T: 949.561.9200 F: 949.561.9201 www.langan.com CR 2SOLDIER PILE WALL LOCATION BUILDING 36 & 37 LEGEND: PROPOSED SOLDIER PILE WALL (LANGAN, 2023) PROPOSED SOLDIER PILE WALL CURRENTLY PART OF CDP PA2023-0034 (KGI, 2023) EXISTING SOLDIER PILE WALL, 36-INCH DIAMETER, 60 FEET DEEP, 7 FEET ON CENTER PRIOR BORING LOCATION AND DEPTH IN FEET (LEROY CRANDALL, 1979) PRIOR BORING LOCATION AND DEPTH IN FEET (LEROY CRANDALL, 1968) LANDSLIDE ZONE (ROCKSOLID, 2023) LANDSLIDE ZONE (LEROY CRANDALL, 1968) SURFICIAL FAILURES/ EROSION/ROCKFALL LANDSLIDE DIRECTION BUILDING NUMBERS4 B-7 100 B-1 51 APPENDIX Prior Pertinent Boring Logs