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HomeMy WebLinkAbout3.0_Park Newport Rockfall Mitigatio_Presentation_Applicant_PA2021-099Park Newport Planning Commission April 21, 2022 Item No. 3 Residential Protection and Rockfall Mitigation Planning Commission - April 21, 2022 Item No. 3e - Additional Materials Presented at Meeting by Applicant Park Newport Rockfall Mitigation (PA2021-099) Location Park Newport Blufftop Planning Commission - April 21, 2022 Item No. 3e - Additional Materials Presented at Meeting by Applicant Park Newport Rockfall Mitigation (PA2021-099) Site History •Built in 1969 (Pre-Coastal Act) •Developed with 1,300 apartments •Small to large landslides:1978, 1993, 1994, 2000, 2005, 2020 •Rock fall:1998, 2005, 2006, 2009, 2016 •Small to large shallow slope failures occur in years with long duration and/or high intensity rainfall •Erosion takes place during most rainfall events •Geotechnical Evaluations of site since 1969 including 25 years of on-site analysis by project Geotechnical Engineer Planning Commission - April 21, 2022 Item No. 3e - Additional Materials Presented at Meeting by Applicant Park Newport Rockfall Mitigation (PA2021-099) Prior Improvements •1970s –Timber Pile/Wood Lagging Retaining Wall, west side of Units 4570 through 4640. Eighteen piles of 10-feet bedrock embedment. •1998 –Soldier Pile Wall, west side of clubhouse. Twenty-three, 36-inch diameter, 7-feet on-center, 60-feet deep reinforced concrete caissons. •1998 –Soldier Pile Wall, southwest side of Unit 4570. Six 48-inch diameter, 8-feet on-center, 60-feet deep, reinforced concrete caissons. Planning Commission - April 21, 2022 Item No. 3e - Additional Materials Presented at Meeting by Applicant Park Newport Rockfall Mitigation (PA2021-099) Planning Commission - April 21, 2022 Item No. 3e - Additional Materials Presented at Meeting by Applicant Park Newport Rockfall Mitigation (PA2021-099) June 2020 Landslide •Large failure exposed 10’ high vertical scarp •Resulted in substantial, on-going rockfall •Rockfall created a hazard to pedestrians and vehicles below •Emergency closure of Back Bay Drive from June 2020 until April 2021 Planning Commission - April 21, 2022 Item No. 3e - Additional Materials Presented at Meeting by Applicant Park Newport Rockfall Mitigation (PA2021-099) Planning Commission - April 21, 2022 Item No. 3e - Additional Materials Presented at Meeting by Applicant Park Newport Rockfall Mitigation (PA2021-099) Planning Commission - April 21, 2022 Item No. 3e - Additional Materials Presented at Meeting by Applicant Park Newport Rockfall Mitigation (PA2021-099) Planning Commission - April 21, 2022 Item No. 3e - Additional Materials Presented at Meeting by Applicant Park Newport Rockfall Mitigation (PA2021-099) Coastal Development Permit •Emergency CDP •Steel Mesh •Annual Tarping of unvegetated, eroded areas •K-rail placement •CDP •Formalize emergency CDP •Soldier Piles Planning Commission - April 21, 2022 Item No. 3e - Additional Materials Presented at Meeting by Applicant Park Newport Rockfall Mitigation (PA2021-099) Steel Mesh -Emergency CDP •Steel mesh system installed (40-60’ wide x 58’ high) on upper portion of bluff where additional failure/rockfall most likely •Purpose to reduce rockfall and debris from falling to Back Bay Drive •Installation allowed Back Bay Drive to safely reopen for vehicular traffic Planning Commission - April 21, 2022 Item No. 3e - Additional Materials Presented at Meeting by Applicant Park Newport Rockfall Mitigation (PA2021-099) Planning Commission - April 21, 2022 Item No. 3e - Additional Materials Presented at Meeting by Applicant Park Newport Rockfall Mitigation (PA2021-099) Planning Commission - April 21, 2022 Item No. 3e - Additional Materials Presented at Meeting by Applicant Park Newport Rockfall Mitigation (PA2021-099) Annual Tarping –Emergency CDP •Key technical recommendation from Hetherington Engineering to slow rate of erosion on the bluff •Tarps (commercial-grade visqueen) in place during rainy season (Oct./Nov. –April) •Tarping on-going for past 25 years •Committed to sourcing neutral colored commercial-grade visqueen, or to applying camouflaging material on top of visqueen Planning Commission - April 21, 2022 Item No. 3e - Additional Materials Presented at Meeting by Applicant Park Newport Rockfall Mitigation (PA2021-099) K-Rail Placement –Emergency CDP Requires Waiver of City Council Policy L-6 for improvements encroaching more than 1 ft into the public right of way. Each K-Rail 20’ Long/32” High Section 1 Nine (9) K Rail Totaling 180 ft Approx. 4′ to 13′1″from Roadway Section 2 Five (5) K Rail Totaling 100 ft Approx. 2′to 3′3″from Roadway Section 3 Six (6) K Rail Totaling 108 ft Approx. 6′8″to 3′9″from Roadway Planning Commission - April 21, 2022 Item No. 3e - Additional Materials Presented at Meeting by Applicant Park Newport Rockfall Mitigation (PA2021-099) Planning Commission - April 21, 2022 Item No. 3e - Additional Materials Presented at Meeting by Applicant Park Newport Rockfall Mitigation (PA2021-099) Drilled Piers/Soldier Piles -CDP •Soldier piles 36 to 48 inches in diameter •Drilled to depth of 60 to 70 feet •Extend existing soldier piles to the south past Unit 4830, approx. 150 ft (approx. 20 soldier piles) •Install soldier piles on the southeast side of building 4, approx. 200 ft (approx. 28 soldier piles) •Installed underground –not visible Planning Commission - April 21, 2022 Item No. 3e - Additional Materials Presented at Meeting by Applicant Park Newport Rockfall Mitigation (PA2021-099) Planning Commission - April 21, 2022 Item No. 3e - Additional Materials Presented at Meeting by Applicant Park Newport Rockfall Mitigation (PA2021-099) Existing Soldier Pile Wall (1998) Existing Soldier Pile Wall (1998) Proposed Soldier Pile Wall Existing Wood Retaining Wall (1979) Proposed Soldier Pile Wall Planning Commission - April 21, 2022 Item No. 3e - Additional Materials Presented at Meeting by Applicant Park Newport Rockfall Mitigation (PA2021-099) Planning Commission - April 21, 2022 Item No. 3e - Additional Materials Presented at Meeting by Applicant Park Newport Rockfall Mitigation (PA2021-099) Planning Commission - April 21, 2022 Item No. 3e - Additional Materials Presented at Meeting by Applicant Park Newport Rockfall Mitigation (PA2021-099) LIP Section 21.30.030(c)(3) Protective Structures •Project consistent with LIP which allows for protective structures in limited instances •Development pre-dates the Coastal Act •Work limited to protecting the primary structures •Considered the minimum amount of work necessary •No enlargement or expansion, no new development •No impact to coastal waters Planning Commission - April 21, 2022 Item No. 3e - Additional Materials Presented at Meeting by Applicant Park Newport Rockfall Mitigation (PA2021-099) Alternatives Analysis •Evaluated range of project alternatives •Proposed project determined to be least environmentally damaging practicable alternative based on landform modification, biological resources, coastal views, and public access •All other alternatives would result in greater impacts Planning Commission - April 21, 2022 Item No. 3e - Additional Materials Presented at Meeting by Applicant Park Newport Rockfall Mitigation (PA2021-099) Conclusion •Project is consistent with the City’s LCP and Chapter 3 of the Coastal Act •Committed to finding neutral colored commercial-grade visqueen or other camouflaging for tarps •Findings can be made for the issuance of a CDP and encroachment waiver pursuant to Council Policy L-6 Planning Commission - April 21, 2022 Item No. 3e - Additional Materials Presented at Meeting by Applicant Park Newport Rockfall Mitigation (PA2021-099) Requested Action •Approve CDP CD2021-001 for rockfall mitigation and primary structure protection •Waive City Council Policy L-6 for k-rail sections that encroach more than 1 foot into the public right of way Planning Commission - April 21, 2022 Item No. 3e - Additional Materials Presented at Meeting by Applicant Park Newport Rockfall Mitigation (PA2021-099) Planning Commission - April 21, 2022 Item No. 3e - Additional Materials Presented at Meeting by Applicant Park Newport Rockfall Mitigation (PA2021-099) Planning Commission - April 21, 2022 Item No. 3e - Additional Materials Presented at Meeting by Applicant Park Newport Rockfall Mitigation (PA2021-099) Planning Commission - April 21, 2022 Item No. 3e - Additional Materials Presented at Meeting by Applicant Park Newport Rockfall Mitigation (PA2021-099) Planning Commission - April 21, 2022 Item No. 3e - Additional Materials Presented at Meeting by Applicant Park Newport Rockfall Mitigation (PA2021-099) Planning Commission - April 21, 2022 Item No. 3e - Additional Materials Presented at Meeting by Applicant Park Newport Rockfall Mitigation (PA2021-099) Planning Commission - April 21, 2022 Item No. 3e - Additional Materials Presented at Meeting by Applicant Park Newport Rockfall Mitigation (PA2021-099) Planning Commission - April 21, 2022 Item No. 3e - Additional Materials Presented at Meeting by Applicant Park Newport Rockfall Mitigation (PA2021-099) Planning Commission - April 21, 2022 Item No. 3e - Additional Materials Presented at Meeting by Applicant Park Newport Rockfall Mitigation (PA2021-099) Planning Commission - April 21, 2022 Item No. 3e - Additional Materials Presented at Meeting by Applicant Park Newport Rockfall Mitigation (PA2021-099) Planning Commission - April 21, 2022 Item No. 3e - Additional Materials Presented at Meeting by Applicant Park Newport Rockfall Mitigation (PA2021-099) Planning Commission - April 21, 2022 Item No. 3e - Additional Materials Presented at Meeting by Applicant Park Newport Rockfall Mitigation (PA2021-099) Planning Commission - April 21, 2022 Item No. 3e - Additional Materials Presented at Meeting by Applicant Park Newport Rockfall Mitigation (PA2021-099) Planning Commission - April 21, 2022 Item No. 3e - Additional Materials Presented at Meeting by Applicant Park Newport Rockfall Mitigation (PA2021-099) LIP Section 21.30 Consistency “Provides regulations for the protection of natural landforms and shoreline features. The intent is to ensure that development is sited and designed to minimize hazards to life and property; to ensure the structural integrity of bluffs and canyons; to neither create nor contribute to erosion or adverse impacts on shoreline sand supply and the shoreline; to maintain a system of harbor bulkheads that are essential to the continued operation of Newport Harbor and to protect public access, public views, and scenic qualities of the coastal zone; and to implement policies of the Coastal Land Use Plan.” •Park Newport Developed in 1969 •Development Limited to Mitigation and Protection •Rockfall Mitigation Measures will Minimize Erosion •Soldier Piles will Protect Residential Structures which pre-date the Coastal Act •Not an Ocean Bluff/No Impact on Sand Supply •Help ensure Back Bay Drive remains open for recreation and vehicle traffic •Materials chosen for minimal aesthetic impact Local Costal Program Planning Commission - April 21, 2022 Item No. 3e - Additional Materials Presented at Meeting by Applicant Park Newport Rockfall Mitigation (PA2021-099) Chapter 3 Coastal Resources Consistency Article 2 Public Access Article 3 Recreation •Consistent with §30211, development does not interfere with public access. Rockfall mitigation will help ensure public safety and keep Back Bay Drive open to the public. •Consistent with §30221, development protects public recreational activities. Rockfall mitigation will help to ensure bicycling and pedestrian access to Upper Newport Bay and parking access for Big Canyon trail remain accessible. California Coastal Act Planning Commission - April 21, 2022 Item No. 3e - Additional Materials Presented at Meeting by Applicant Park Newport Rockfall Mitigation (PA2021-099) Chapter 3 Coastal Resources Consistency Article 4 Marine Environment Article 5 Land Resources •Consistent with §30235, development will protect existing structures and will not have an adverse impact on sand supply. The buildings requiring protection are existing buildings that predate the Coastal Act. •Consistent with §30240, development will protect sensitive habitat. A preconstruction biological and avian survey was conducted and will be required for future work. Rockfall mitigation is designed to prevent impacts to habitat. California Coastal Act Planning Commission - April 21, 2022 Item No. 3e - Additional Materials Presented at Meeting by Applicant Park Newport Rockfall Mitigation (PA2021-099) Chapter 3 Coastal Resources Consistency Article 6 Development •Consistent with §30250, rockfall mitigation helps to protect Back Bay Drive and parking lot–a visitor serving facility that cannot be relocated. •Consistent with §30251, scenic and visual quality of Upper Newport Bay will be preserved. Tarps will be used only during the rainy season and removed when not necessary. K rail are 32” in height. Mesh is low profile against scarp. Soldier piles will not be visible to the public. California Coastal Act Planning Commission - April 21, 2022 Item No. 3e - Additional Materials Presented at Meeting by Applicant Park Newport Rockfall Mitigation (PA2021-099) Chapter 3 Coastal Resources Consistency Article 6 Development •Consistent with §30252, development will maintain and enhance public access. Rockfall mitigation will help ensure that Back Bay Drive and the parking lot remains open to the public. •Consistent with §30253, development will minimize risks to life and property. Rockfall mitigation will protect pedestrians, bicyclists, and vehicles traveling along Back Bay Drive. Installation of soldier piles will protect existing structures and their residents. It will not substantially alter the natural landform. California Coastal Act Planning Commission - April 21, 2022 Item No. 3e - Additional Materials Presented at Meeting by Applicant Park Newport Rockfall Mitigation (PA2021-099) K-Rail Placement Private encroachments that are prohibited without a waiver and approval. A.All structural encroachments including, but not limited to,fences,walls,patios,raised planters, landscaping,etc.,which encroach in excess of one (1) -foot into the public right-of-way,or exceed thee ( 3) -feet in height,measured from the top of curb elevation/or from sidewalk elevation where sidewalk exists. B.Driveway approaches not conforming to Council Policy L-2. C.Modifications to original design concepts approved by the City. D Private signs except as provided for in the Building Code. E.Lighting. F.Parkway walkway surfacing of loose rock,gravel,or any surfacing other than standard or colored/textured concrete or flat stone/brick/ pavers installed at grade. G.Private dwellings and appendages including raised patios decks and bay windows,except as provided for in this section and the Building Code. H.Pay telephones and private mail carriers drop boxes. Planning Commission - April 21, 2022 Item No. 3e - Additional Materials Presented at Meeting by Applicant Park Newport Rockfall Mitigation (PA2021-099) Emergency CDP No. CD2021-001 •In response to a rockslide in June 2020 that forced the closure of Back Bay Drive.•Emergency Work Included: •Installation of mesh totaling 2,900 sf secured by 8 boundary anchors, 5 spot anchors and 41 pattern anchors •Placement of K rail barrier (5 totaling 100 ft)•The emergency work helps prevent surficial rockslides and stop small debris from reaching Back Bay Drive.•Work Completed on March 26, 2021 and Back Bay Drive was Determined to be Safe for Vehicular Traffic April 2021. Authorized January 22, 2021 Planning Commission - April 21, 2022 Item No. 3e - Additional Materials Presented at Meeting by Applicant Park Newport Rockfall Mitigation (PA2021-099) Emergency Permits and CDP •Emergency Permit CD2021-001 –Authorized January 22, 2021 / Work Complete March 2021. •Emergency Permit CD2021-066 –Authorized October 25, 2021 / Work Complete November 2022. •Coastal Development Permit CD2021- 001/PA2021-099 –Applied April 22, 2021. Planning Commission - April 21, 2022 Item No. 3e - Additional Materials Presented at Meeting by Applicant Park Newport Rockfall Mitigation (PA2021-099) Emergency CDP No. CD2021-066 Authorized October 26, 2021 •In Response to Upcoming Rainy Season •Emergency Work Included: •Installation of tarps on slope •Secured with similar color sandbags •Minimize erosion and debris •Evaluation by geotechnical engineer •Annual temporary placement •Seasonal basis during rainy season (October-April) •Placed in three locations along the slope Planning Commission - April 21, 2022 Item No. 3e - Additional Materials Presented at Meeting by Applicant Park Newport Rockfall Mitigation (PA2021-099) Planning Commission - April 21, 2022 Item No. 3e - Additional Materials Presented at Meeting by Applicant Park Newport Rockfall Mitigation (PA2021-099) Planning Commission - April 21, 2022 Item No. 3e - Additional Materials Presented at Meeting by Applicant Park Newport Rockfall Mitigation (PA2021-099) Planning Commission - April 21, 2022 Item No. 3e - Additional Materials Presented at Meeting by Applicant Park Newport Rockfall Mitigation (PA2021-099) Planning Commission - April 21, 2022 Item No. 3e - Additional Materials Presented at Meeting by Applicant Park Newport Rockfall Mitigation (PA2021-099)