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HomeMy WebLinkAbout20221123_REVISED_Coastal Hazards Analysis Report WILLIAM SIMPSON & ASSOCIATES, INC. CONSULTING STRUCTURAL ENGINEERS 23 ORCHARD, SUITE 250 H. (949) 206-9929 LAKE FOREST, CA 92630 FAX (949) 206-9955 www.wsase.com e-mail: Tmail@wsase.comT November 13, 2020 Mr. Ronald Ritner Ritner Group 503 32nd St., Suite#130 Newport Beach, CA 92663 RE: COASTAL HAZARDS ANALYSIS REPORT IN RESPONSE TO ITEM 6 OF NOTICE OF INCOMPLATE APPLICATION Application No. Coastal Development Permit No. CD2020-135 (PA2020-256) Address: 74 Linda Isle Newport Beach, County of Orange WSA Job # 7507 Dear Mr. Ritner, William Simpson & Associates, Inc., (WSA) is pleased to provide this report regarding Coastal Hazards Analysis for the proposed development at the subject site. The site is adjacent to Newport Bay; thus, it may be subject to Coastal Hazards such as, flooding, wave runup, and erosion. This study investigates the potential for the aforementioned hazards to impact the proposed development on the site over the next 75 years and addresses compliance with Coastal Hazards Analysis Report requirements and standards of NBMC Section 21.30.15.E.2. STATEMENT OF THE PREPARER’S QUALIFICATIONS I, the preparer of this report, holding a Bachelor of Science Degree in Structural Engineering from Tehran, Iran, am a Licensed Civil and Structural Engineer - Certificate Nos. C43673 and S3812, respectively - by the State of California. I joined the company in 1987 and am now partly the owner, and serve as the principal in charge of the company. I have been actively involved in the design and entitlement of waterfront developments such as custom homes, seawalls, piers, platforms, floating docks and marinas for over 30 years. All the above being said, I shall be considered qualified for preparing the Coastal Hazards Analysis Report on this project. Requirements in Appendix A for Step 1: Establish the project sea level rise range for the proposed project’s planning horizon (life of project) using the current best available science. The State of California Sea-Level Rise Guidance 2018 update developed by the Ocean Protection Council in close coordination with Policy Advisory Committee with representation from California Natural Resources Agency, the Governor’s Office of Planning and Research, and the California Energy Commission provides a bold, science-based methodology for state and local governments to analyze and assess the risks associated with sea-level rise, and to incorporate Sea-Level Rise into their planning, permitting, and investment decisions, and it is considered the current best available science. In accordance with the guidance and requirements by California Coastal Commission, as reflected in the clouded area of the enclosed Table 28, based upon direct interpolation of the data for High emissions 2090 & 2100 and Medium-High Risk Aversion, over the project’s planning horizon of 75 years, the estimated Sea-Level Rise (SLR) for year 2095 shall be 6.00’, which is the Sea- Level Rise for the proposed project. Based on the highest high tide of +7.88’MLLW (7.70’NAVD88) recorded in the project area, the above established Sea-Level Rise will account for bay water level of +13.70’NAVD88. Per City of Newport Beach Municipal Code standards, we have enclosed Table 28 with interpolated data for High emissions 2090 & 2100 and Low Risk Aversion. Based on that interpolation, the estimated SLR for year 2095 shall be approximately 2.95’, which is much smaller than the governing estimated SLR for Medium-High Risk Aversion. Based on the highest high tide of +7.88’MLLW (7.70’NAVD88) recorded in the project area, the above established Sea-Level Rise will account for bay water level of +10.65’NAVD88. Requirements in Appendix A for Step 2: Determine how physical impacts from sea level rise may constrain the project site, including erosion, structural and geologic stability, flooding, and inundation. According to the enclosed Site Plan SP-1 finished of 1 st floor elevation of the proposed development shall be at +10.90’ NAVD88=+11.08’MLLW which follow the Base Flood Elevation established for the area. Based on the SLR established in Step 1 above, 1st floor of the proposed structure will remain above High Tide sea level approximately until year of 2060 upon Medium- High Risk Aversion probabilistic projections and until after year of 2195 upon Low Risk Aversion probabilistic projections. As we well know, majority of the public streets in Newport Bay area are currently at much lower elevations than the subject site and they will flood due to SLR way before the development on this site becomes subject to flooding. FLOODING HAZARD The primary hazard due to flooding from the ocean waters for this site, like majority of the sites located adjacent to Newport Bay, would be due to long term Sea-Level Rise. The current water levels in Newport Bay are reflected on the enclosed Datums for Newport Bay Entrance. While Sea-Levels have been Rising for decades, higher rates of raise are forecast for the coming century because of climate change – see enclosed table 28. Increases can be attributed to warmer temperatures, which cause water to expand, as well more liquid mass caused by melting of ice caps. Current estimates of future SLR generally fall in the range of 5.4-6.7 ft for the year 2100. Global warming may impact flooding in other ways as well. Warmer water could intensify North Pacific storms, bringing greater wind and wave energy to shoreline in winter and higher intensity precipitation. The Newport Beach Peninsula portion of the Pacific Institute California Flood Risk Map is shown herein as OE S Quadrangle. The dark blue colored areas show the areas where a 100-year Sea-Level Rise of 55 inches is added to the existing FEMA coastal flood elevation shown in light blue. Obviously, the entire Newport Bay area will be affected if sea level rises 55 inches by the year 2100. If the sea level rises in the next several decades as currently estimated, regional measures to mitigate the potential flooding hazard shall be taken. As determined in Step 2 above, 1st floor elevation of the proposed structure will remain below High Tide sea level approximately until year of 2060 for the most conservative scenario of the probabilistic projections. In the event that SLR prediction of 6.00’ for year of 2095 holds true, the concrete deck has been designed to accommodate raise to top of wall elevation of +13.7’NAVD88, as reflected on the enclosed S-0 thru S-2. WAVE RUNUP AND TSUNAMI Wave runup is the uprush of water from wave action on a shore barrier intercepting Stillwater level. On steeply sloped shorelines, the rush of water up the surface of the natural beach, including dunes and bluffs, or the surface of a manmade structure, such as revetment or vertical wall can result in flood elevations higher than those of the crest of wind-driven waves. See Wave Runup Sketch & ACSE Diagram below. Due to its location, this site is not a subject to typical ocean waves and the associated wave runup. Bay generated waves that may arrive at this site are very small wind waves and boat wakes. These types of waves are generally dampened by the moored vessels and dock systems located in front of the site and have no significant energy and runup effect. Tsunami type waves that approach from the ocean shoreline will likely not reach the site for several reasons. There is no significant near field source of a tsunami like the geologic conditions of some other places on Earth such as Japan, for example. A far field tsunami reaching the ocean shoreline will likely not reach the site because of the distance and developments between the shoreline and this site. A near or far field tsunami propagating into Newport Bay proper would likely cause a seiche or standing wave on the order of 1.3 feet traveling within the bay. At the highest anticipated tide in Newport Beach of +7.88’MLLW this shall result in slight overtopping of the bulkhead/seawall. Due to its very infrequent occurrence – 500-year recurrence interval – tsunami should not be considered a significant impact over the life of the proposed structure -75 years. EROSION HAZARD Erosion refers to the wearing or washing away of coastal lands. Beach erosion is a chronic problem along many open ocean shores of the United States. To meet the needs for comprehensive analysis of shoreline movement, the United States Geological Survey has conducted analysis of historical shoreline changes along open ocean sandy shores of the conterminous United States and has produced an Open-File Report 2006-1219 entitled “National Assessment of Shoreline Change Part 3: Historical Shoreline Change and Associated Coastal land Loss Along Sandy Shorelines of the California Coast”. The report looks at survey data of the following periods: 1800s, 1920s-1930s, and 1950s-1970s, whereas the lidar shoreline is from 1998-2002. The report looks at both long-term and short-term changes. According to the report, the average rate of long-term shoreline changes for the State of California was 0.2±0.1 m/yr., and accretional trend. The average rate of short-term shoreline change for the state was erosional; with an average rate of -0.2±0.4 m/yr. The beach footprint of this site is stabilized and not subject to significant long-term erosion. Review and analysis of historical aerial photographs and field measurements for seawall repairs in the area show no change in the position of the shoreline over the last several decades. The future shoreline changes over the next 75 years are assumed to be the same as in the previous several decades. However, there is a rapid rate of SLR predicted in the next 75 years. If that prediction holds true, the rapid SLR may accelerate shoreline erosion, but it shall not impact the structure on the subject lot over its economic life. CONCLUSION In conclusion, flooding, wave runup and erosion will not significantly impact this property over the proposed life of the development. The existing seawall/bulkhead is required to protect the proposed structures on the lot, the adjacent properties, public facilities and infrastructure; thus, it can’t be removed. Removal of the seawall/bulkhead will result in erosion and undermining the foundations of the structures and site walls at the subject site and both adjacent sites. Once the existing seawall/bulkhead is repaired/reinforced in compliance with the enclosed drawings S-0 thru S-2, need for a new shoreline protective devise shall not anticipated over the economic life of the proposed development to protect it from flooding, wave runup or erosion. Waterproofing flashing or waterproofing curbs around the perimeter of habitable rooms shall not be required. If found not adequate for the actual sea level rise over the next 75 years, the existing seawall/bulkhead assembly, including the concrete wall at the entire bayward edge of the new concrete deck, allows to be increased in height to+13.7’NAVD88 without further seaward encroachment. If during this period the seawall/bulkhead displays any sign of distress that requires immediate attention, due to some unforeseen catastrophic or disastrous events, it should be repaired or replaced at that time accordingly, without seaward encroachment from its current location. The above conclusion was prepared based on the existing conditions, proposed drawings, current projections of future Sea-Level Rise, and within the inherent limitations of this study, in accordance with generally acceptable engineering principles and practices. We make no further warranty, either expressed or implied. William Simpson & Associates, Inc. appreciates the opportunity to work with you towards the successful completion of your project. Should you have any questions regarding this report, please give us a call. Respectfully submitted, Masoud Jafari, S.E. Principal Enclosures: Location Map Aerial View Topographic Survey Site Plan SP-1 Table 28: Projected Sea-Level Rise (in feet) for Los Angeles 2095 Medium-High Risk Aversion Table 28: Projected Sea-Level Rise (in feet) for Los Angeles 2095 Low Risk Aversion Datums for Newport Bay Entrance Newport Beach OE S Quadrangle Seawall Drawings S-0 thru S-2 ℄Δ=29°11'32"R=40.00'L=20.38'Δ=30°45'45"R=164.00'L=88.05'Δ=30°49'17"R=178.00'L=95.75'PRIVATECHANNELtrash trash3-CarGarageBedroom 4coats OutdoorRoomLivingRoomPdrEntryFoyerKitchenBath 4Chef'sKitchenWicstoragePoolBathPoolEquipEntryVestibuleelevatorhallstairhallT.O.(N) Wall Elev10.70' NAVD88T.O.(E) Coping Elev9.00' NAVD88Refer to Seawall DrawingsPrepared By:William Simpson & AssociatesStone PaverSystem overPaving PedestalsOver CocreteDeck BelowReplaceexisting concretedeck, add 6"concrete curbpaverFS El. 11.40'F.S. El. 10.90FS El. 10.90'paverFS El. 11.08'T.O.Paver El. 10.90'T.O.Deck El. 9.74'F.F. El. 11.78F.F. El. 10.90F.F. El. 11.4 7F.F. El. 11.70FS El. 11.50'F.F. El. 10.925New42" HighGuardrail36" widePlanterPlanterPlanter Planter SpaPlanterHardscape F.S. El. 10.904'-0"Setback4'-0"Setback10-0"SetbackProperty LineProperty LineProperty LineProperty LineA.N.G.Point 29.74'A.N.G.Point 411.40'A.N.G.Point 111.35'20' x 28'-3" min.Parking Required25'Setback14'Architectural Site PlanSCALE: 1/8" = 1'-0"ARCHITECTURALSITE PLANPLOT REFERENCE DATE: 11-18-20SHEET NUMBER:503 32ND STREET, SUITE 130TELEPHONE: (949) 999-3255NEWPORT BEACH, CA 92663FAX: (949) 999-3259STAMP:TELEPHONE:FAX:SP-1SHEET TITLE:© RITNER GROUP, INC. 2020 expressly reserves allcommon law copyright and property rights in these plans.These plans are not to be reproduced, changed orcopied in any form or manner whatsoever, nor are theyto be assigned to any third party without first obtaining the express written permission and consent ofRITNER GROUP, INC.PROJECT DESIGNER:PROJECT CAD FILE:PROJECT NUMBER:DRAWN BY:PROJECT MANAGER:20002-SITEO:\2020-PROJECTS\20002\CD\20002-SITE November 19, 2020FGBW20002Julie Mumma513 Dragon Gate CourtHenderson, NV 89012Coastal Development Permit Submittal Set 11-18-20PROJECT:BUILDING DEPARTMENT SUBMITTAL: -REVISIONS:PROJECT ADDRESS74 LINDA ISLENEWPORT BEACH, CA. 92660ASSESOR'S PARCEL NUMBER: 050-451-33LOT 74, TRACT 4003Area for Determining slope CaculationA.N.G. Point # 1 11.35'A.N.G. Point # 2 9.74'A.N.G. Point # 3 9.75'A.N.G. Point # 4 11.40'Total 42.24'Divided by 410.56'A.N.G. (Average Natural Grade)Grade EstablishmentSITE PLAN NOTES7. ALL WORK SHALL COMPLY WITH THE 2013 CBC, CMC, CPC, &CEC, TITLE 24 AND LOCAL ORDINANCES.8. A CERTIFIED ENGINEERING GEOLOGIST SHALL INSPECT ANDAPPROVE ALL GRADING AND EXCAVATIONS PRIOR TOPLACEMENT OF FORMS, REBAR OR CONCRETE. IFENGINEERED SOIL IS REQUIRED, THE SOIL ENGINEER SHALLINSPECT AND APPROVE.9. IN ADDITION TO REGULAR INSPECTIONS, SPECIALINSPECTIONS PER CBC SHALL BE REQUIRED FOR FIELDWELDING, HIGH STRENGTH BOLTS, EXPANSION ANCHORS ANDSPECIAL MASONRY.10. CONTRACTOR SHALL OBTAIN OSHA PERMIT FOREXCAVATIONS DEEPER THAN 5'-0".11. ANY EXISTING CONDITIONS THAT VARY FROM THOSE SHOWNSHALL BE BROUGHT TO THE ATTENTION OF THE ARCHITECTIMMEDIATELY AND ALL WORK IN THE AREA STOPPED UNTILOWNER OR ARCHITECT GIVE APPROVAL TO PROCEED.12. ALL WORK SHALL BE DONE IN ACCORDANCE WITH LOCALCODES, ORDINANCES AND LAWS.13. ALL MECHANICAL AND ELECTRICAL WORK SHALL BE DONE ONA DESIGN . CONSTRUCT BASIS BY THE GENERALCONTRACTOR UNDER PERMITS GRANTED BY THE CITYBUILDING OFFICIAL.14. PROVIDE GUARDRAIL PER CBC AT ANY "HUMAN ACCESSIBLEOPEN AREA" WHERE A DROP OFF IN EXCESS OF 30" OCCURS.15. ALL WEATHER EXPOSED SURFACES SHALL HAVE A WEATHERRESISTIVE BARRIER TO PROTECT THE INTERIOR WALLCOVERING, AND EXTERIOR OPENINGS SHALL BE FLASHED INSUCH A MANNER AS TO MAKE THEM WEATHERPROOF.16. SLOPE GRADE A MINIMUM OF 14" PER FOOT AWAY FROMSTRUCTURE FOR 3'-0" AND WHERE NECESSARY TO AVOIDPONDING.17. MASONRY CHIMNEYS SHALL BE CONSTRUCTED ACCORDINGTO THE CALIFORNIA BUILDING CODE. FACTORY BUILTCHIMNEYS SHALL BE INSTALLED IN ACCORDANCE WITH THECALIFORNIA MECHANICAL CODE AND THE MANUFACTURER'SRECOMMENDATIONS. SEPARATION FROM COMBUSTIBLESSHOULD BE A MINIMUM OF 3 FEET. FACTORY BUILT FIREPLACESHALL BE LISTED FOR USE. ALL OUTDOOR CHIMNEY'S SHALLBE NATURAL GAS ONLY.18. SUCH DEVICES, STRUCTURES OR EQUIPMENT SHALL NOT BEUSED FOR THE DISPOSAL OF RUBBISH, TRASH ORCOMBUSTIBLE MATERIALS THAT PRODUCE OBJECTIONABLESMOKE OR ODOR EMISSIONS.19. SUCH DEVICES, STRUCTURES OR EQUIPMENT SHALL NOT BELOCATED WITHIN THREE FEET OF ANY COMBUSTIBLESTRUCTURE, COMBUSTIBLE MATERIAL OR VEGETATION ANDFOLLOW THE MANUFACTURER'S RECOMMENDATIONS FORCLEARANCES.20. TIKI TYPE TORCHES MAY NOT BE LOCATED WITHIN TEN FEETOF ANY COMBUSTIBLE MATERIAL21. OPEN BURNING THAT IS OFFENSIVE OR OBJECTIONABLEBECAUSE OF SMOKE ODOR EMISSIONS AS DETERMINED BYTHE FIRE CODE OFFICIAL OR HE OR HER DESIGNEE (FIRECAPTAINS) OR WHEN ATMOSPHERIC CONDITIONS OR LOCALCIRCUMSTANCE MAKE SUCH FIRES HAZARDOUS SHALL BEPROHIBITED.1. THE DISCHARGE OF POLLUTANTS TO ANY STORM DRAINAGESYSTEM IS PROHIBITED. NO SOLID WASTE PETROLEUMBYPRODUCTS, SOIL PARTICULATE, CONSTRUCTION WASTEMATERIALS, OR WASTEWATER GENERATED ONCONSTRUCTION SITES OR BY CONSTRUCTION ACTIVITIESSHALL BE PACED, CONVEYED OR DISCHARGED INTO THESTREET, GUTTER OR OTHER PORTION OF ANY STORM DRAINSYSTEM.2. PRIOR TO ISSUANCE OF A BUILDING PERMIT, THE SEWERLATERAL SHALL BE VIDEO TAPED AND AN INSPECTIONREPORT ON THE RESULTS OF THE VIDEOTAPING SUBMITTEDTO THE CITY BY A PLUMBER AUTHORIZED BY THE CITY, PERORDINANCE 1439, CHAPTER 17.50 OF THE CITY OF LAGUNABEACH MUNICIPAL CODE .3. ALL CONSTRUCTION AND DEMOLITION DEBRIS SHALL BEDISPOSED OF PER THE CITY OF LAGUNA BEACH'SCONSTRUCTION AND DEMOLITION WASTE DISPOSALORDINANCE. CONTRACTOR TO SUBMIT REQUIRED FORM TOTHE COMMUNITY DEVELOPMENT DEPARTMENT AND USEWASTE MANAGEMENT ROLL-OFF BINS FOR ALL DEBRIS TOCOMPLY WITH THE ORDINANCE, CALL (949) 642-1191 TOORDER BINS FOR THIS PURPOSE.4. REFER TO SITE DRAINAGE PLAN SHEET FOR EXISTING GRADEELEVATIONS AND FINISH GRADE ELEVATIONS5. SURVEYOR OR ENGINEER SHALL PERMANENTLY MONUMENTPROPERTY CORNERS OR OFFSETS BEFORE STARTINGGRADING.6. FENCES, GATES, WALLS, PLANTER BOXES, PATIO COVERS,AND OTHER FREESTANDING STRUCTURES CANNOT EXCEED 6'MEASURED FROM NATURAL GRADE WITHIN THE REQUIREDSIDE YARD SETBACK.Area TabulationsFirst Floor (Livable): *2,050 Sq. Ft.Trash Alcove:22 Sq. Ft.Total (Livable): 5,304 Sq. Ft.Covered Entry Vestibule:214 Sq. Ft.Second Floor (Livable): * 3,254 Sq. Ft.Garage Mechanical: * 867 Sq. Ft.Total:867 Sq. Ft.Proposed Building Area: *Total (Livable):5,304 Sq. Ft.Garage / Mechanical: 867 Sq. Ft.Total Proposed Building Area: 6,194 Sq. Ft.Covered Outdoor Dining:328 Sq. Ft.Pool Bath: * 23 Sq. Ft.Pool Bath:23 Sq. Ft.Allowable Building Area(Site Area minus Setbacks)Total (Livable): 10,976 Sq. Ft.Allowable Building Area x 2 x 25,488 Sq. Ft. Probabilistic Projections (in feet) (based on Kopp et al. 2014) H++ scenario (Sweet et al. 2017) *Single scenario MEDIAN LIKELY RANGE 1-IN-20 CHANCE 1-IN-200 CHANCE 50% probability sea-level rise meets or exceeds… 66% probability sea-level rise is between… 5% probability sea-level rise meets or exceeds… 0.5% probability sea-level rise meets or exceeds… Low Risk Aversion Medium - High Risk Aversion Extreme Risk Aversion High emissions 2030 0.3 0.2 - 0.5 0.6 0.7 1.0 2040 0.5 0.4 - 0.7 0.9 1.2 1.7 2050 0.7 0.5 - 1.0 1.2 1.8 2.6 Low emissions 2060 0.8 0.5 - 1.1 1.4 2.2 High emissions 2060 1.0 0.7 - 1.3 1.7 2.5 3.7 Low emissions 2070 0.9 0.6 - 1.3 1.8 2.9 High emissions 2070 1.2 0.8 - 1.7 2.2 3.3 5.0 Low emissions 2080 1.0 0.6 - 1.6 2.1 3.6 High emissions 2080 1.5 1.0 - 2.2 2.8 4.3 6.4 Low emissions 2090 1.2 0.7 - 1.8 2.5 4.5 High emissions 2090 1.8 1.2 - 2.7 3.4 5.3 8.0 Low emissions 2100 1.3 0.7 - 2.1 3.0 5.4 High emissions 2100 2.2 1.3 - 3.2 4.1 6.7 9.9 Low emissions 2110* 1.4 0.9 - 2.2 3.1 6.0 High emissions 2110* 2.3 1.6 - 3.3 4.3 7.1 11.5 Low emissions 2120 1.5 0.9 - 2.5 3.6 7.1 High emissions 2120 2.7 1.8 - 3.8 5.0 8.3 13.8 Low emissions 2130 1.7 0.9 - 2.8 4.0 8.1 High emissions 2130 3.0 2.0 - 4.3 5.7 9.7 16.1 Low emissions 2140 1.8 0.9 - 3.0 4.5 9.2 High emissions 2140 3.3 2.2 - 4.9 6.5 11.1 18.7 Low emissions 2150 1.9 0.9 - 3.3 5.1 10.6 High emissions 2150 3.7 2.4 - 5.4 7.3 12.7 21.5 STATE OF CALIFORNIA SEA-LEVEL RISE GUIDANCE APPENDIX 3: SEA-LEVEL RISE PROJECTIONS FOR ALL 12 TIDE GAUGES | 72 TABLE 28: Projected Sea-Level Rise (in feet) for Los Angeles Probabilistic projections for the height of sea-level rise shown below, along with the H++ scenario (depicted in blue in the far right column), as seen in the Rising Seas Report. The H++ projection is a single scenario and does not have an associated likelihood of occurrence as do the probabilistic projections. Probabilistic projections are with respect to a baseline of the year 2000, or more specifically the average relative sea level over 1991 - 2009. High emissions represents RCP 8.5; low emissions represents RCP 2.6. Recommended projections for use in low, medium-high and extreme risk aversion decisions are outlined in blue boxes below. *Most of the available climate model experiments do not extend beyond 2100. The resulting reduction in model availability causes a small dip in projections between 2100 and 2110, as well as a shift in uncertainty estimates (see Kopp et al. 2014). Use of 2110 projections should be done with caution and with acknowledgement of increased uncertainty around these projections. Probabilistic Projections (in feet) (based on Kopp et al. 2014) H++ scenario (Sweet et al. 2017) *Single scenario MEDIAN LIKELY RANGE 1-IN-20 CHANCE 1-IN-200 CHANCE 50% probability sea-level rise meets or exceeds… 66% probability sea-level rise is between… 5% probability sea-level rise meets or exceeds… 0.5% probability sea-level rise meets or exceeds… Low Risk Aversion Medium - High Risk Aversion Extreme Risk Aversion High emissions 2030 0.3 0.2 - 0.5 0.6 0.7 1.0 2040 0.5 0.4 - 0.7 0.9 1.2 1.7 2050 0.7 0.5 - 1.0 1.2 1.8 2.6 Low emissions 2060 0.8 0.5 - 1.1 1.4 2.2 High emissions 2060 1.0 0.7 - 1.3 1.7 2.5 3.7 Low emissions 2070 0.9 0.6 - 1.3 1.8 2.9 High emissions 2070 1.2 0.8 - 1.7 2.2 3.3 5.0 Low emissions 2080 1.0 0.6 - 1.6 2.1 3.6 High emissions 2080 1.5 1.0 - 2.2 2.8 4.3 6.4 Low emissions 2090 1.2 0.7 - 1.8 2.5 4.5 High emissions 2090 1.8 1.2 - 2.7 3.4 5.3 8.0 Low emissions 2100 1.3 0.7 - 2.1 3.0 5.4 High emissions 2100 2.2 1.3 - 3.2 4.1 6.7 9.9 Low emissions 2110* 1.4 0.9 - 2.2 3.1 6.0 High emissions 2110* 2.3 1.6 - 3.3 4.3 7.1 11.5 Low emissions 2120 1.5 0.9 - 2.5 3.6 7.1 High emissions 2120 2.7 1.8 - 3.8 5.0 8.3 13.8 Low emissions 2130 1.7 0.9 - 2.8 4.0 8.1 High emissions 2130 3.0 2.0 - 4.3 5.7 9.7 16.1 Low emissions 2140 1.8 0.9 - 3.0 4.5 9.2 High emissions 2140 3.3 2.2 - 4.9 6.5 11.1 18.7 Low emissions 2150 1.9 0.9 - 3.3 5.1 10.6 High emissions 2150 3.7 2.4 - 5.4 7.3 12.7 21.5 STATE OF CALIFORNIA SEA-LEVEL RISE GUIDANCE APPENDIX 3: SEA-LEVEL RISE PROJECTIONS FOR ALL 12 TIDE GAUGES | 72 TABLE 28: Projected Sea-Level Rise (in feet) for Los Angeles Probabilistic projections for the height of sea-level rise shown below, along with the H++ scenario (depicted in blue in the far right column), as seen in the Rising Seas Report. The H++ projection is a single scenario and does not have an associated likelihood of occurrence as do the probabilistic projections. Probabilistic projections are with respect to a baseline of the year 2000, or more specifically the average relative sea level over 1991 - 2009. High emissions represents RCP 8.5; low emissions represents RCP 2.6. Recommended projections for use in low, medium-high and extreme risk aversion decisions are outlined in blue boxes below. *Most of the available climate model experiments do not extend beyond 2100. The resulting reduction in model availability causes a small dip in projections between 2100 and 2110, as well as a shift in uncertainty estimates (see Kopp et al. 2014). Use of 2110 projections should be done with caution and with acknowledgement of increased uncertainty around these projections. Newport BeachNewport Beach Costa MesaCosta MesaCosta MesaCosta MesaHuntington BeachHuntington Beach ¬«1 ¬«55 ¬«1 ¬«55 117°52’30"W 117°52’30"W 117°55’0"W 117°55’0"W 117°57’30"W 117°57’30"W 118°0’0"W 118°0’0"W 33°37’30"N 33°37’30"N 33°35’0"N 33°35’0"N 33°32’30"N 33°32’30"N 33°30’0"N 33°30’0"N 407000mE 407000mE 08 08 09 09 410 410 11 11 12 12 13 13 14 14 15 15 16 16 17 17 18 18 419000mE 419000mE3707000mN37 07000mN08 08 09 09 3710 3710 11 11 12 12 13 13 14 14 15 15 16 16 17 17 18 18 19 19 3720 37203721000mN3721000mN This information is being made available for informational purposes only. Users of this informationagree by their use to hold blameless the State of California, and its respective officers, employees, agents, contractors, and subcontractors for any liability associated with its use in any form. This work shall not be used to assess actual coastal hazards, insurance requirements, or property values and specifically shall not be used in lieu of Flood Insurance Studies and Flood Insurance Rate Maps issued by the Federal Emergency Management Agency (FEMA). Data Sources: US Geological Survey, Department of Commerce (DOC), National Oceanic and Atmospheric Administration (NOAA), National Ocean Service (NOS), Coastal ServicesCenter (CSC), Scripps Institution of Oceanography, Phillip WIlliams and Associates, Inc. (PWA), US Department of Agriculture (USDA), California Coastal Commission, and National Aeronautics and Space Administration (NASA). Imagery from ESRI and i-cubed. Created by the Pacific Institute, Oakland, California, 2009. California Flood Risk: Sea Level Rise 00.511.520.25 Miles 01230.5 Kilometers 1: 2: 3: 4: 5: 6: 7: 8: Seal Beach Newport Beach Tustin not printed Laguna Beach not printed not printed not printed867 1 2 3 54 §¨¦ £¤ ") ¬« Interstate US Highway State Highway County Highway Grid coordinates: UTM Zone 11N meters Adjoining Quadrangles: Map extents match USGS 7.5 minute topographic maps Project funded by the California Energy Commission’s Public Interest Energy Research Program, CalTrans,and the California Ocean Protection Council Newport Beach OE S Quadrangle NAD83 GCS degrees Coastal Zone Boundary Current Coastal Base Flood (approximate 100-year flood extent) Sea Level Rise Scenario Coastal Base Flood + 1.4 meters (55 inches) Landward Limit of Erosion High Hazard Zone in 2100