Loading...
HomeMy WebLinkAbout20190531_Coastal Hazards_5-20-2019GEOTECHNICAL ■MATERIALS ■ SPECIAL INSPECTIONS 24632 San Juan Avenue, Suite 100 Dana Point, California 92629 949.338.7710 Brightview Development, LLC C\O CalPro Engineering & Design, Inc. Mansour@calproengineering.com 949.715.9990 303 Broadway Suite 209 Laguna Beach, CA 9269 51 Subject: Coastal Hazard Analysis Report SBE ■ SCOOP Proposed Single-Family Residence Remodel 3904 River Avenue, Newport Beach, CA 92660 May 20, 2019 Project No.: 3019035 NOV A Services, Inc. (NOV A) has prepared this Coastal Hazard Analysis Report for the proposed development at the subject property. This report investigates the coastal hazard impact to the proposed development over the next 75 years and address compliance with the Coastal Hazard Analysis Report requirements and standards of NBMC Section 21.30.15.E.2. Site Description The subject property is located at 3904 River Avenue, Newport Beach, California. The site is bound by River Avenue to the southwest, single-family residential development to the northwest and southeast, and by Newport Bay to the northeast. The site is bound by Newport Bay to the northeast and may be susceptible to Coastal Hazards such as flooding, wave runup, high tide conditions, sea level rise, erosion, and tsunami inundation. Figures 1 and 2 (following pages) present a vicinity map and an aerial photograph of the subject site. Statement of the Preparers' Qualifications Carl D. Schrenk, CEG, a preparer of the Coastal Hazard Report, holds a B.S. in Geology from University of Utah and has held a license in Certified Engineering Geologist in the state of California for over 40 years. For the last 20 years, he has been actively involved with developments that are located along waterfronts, blufftop and beachfront developments. He also provided geotechnical consulting services on beach access for the Department of Beaches and Parks for the County of Orange. Carl has provided geotechnical consulting services and completed numerous reports for developments susceptible to coastal hazards and were accepted/approved by the California Coastal Commission. Jesse D. Bearfield, PE, a preparer of the Coastal Hazard Report, holds a B.S. in Civil Engineering from South Dakota State University, and is a Licensed Civil Engineer by the State of California, License No. C84335. For the last 4 years of his professional career he has been involved with development along waterfront, blufftop and beachfront developments for many coastal communities in Southern California including for the historic Hotel Del Coronado in San Diego. 24632 San Juan Avenue, Suite 100 I Dana Point, CA 92629 I P :949.338.7710 PA2019-102 Coastal Hazard Analysis Report 3904 River Ave, Newport Beach, California May 20, 2019 NOVA Project No. 3019035 With the years of experience and successful coastal developments, Carl D. Schrenk, CEG, and Jesse D. Bearfield, PE, shall be considered qualified preparers for the Coastal Hazards Analysis Report on this project. Objective Figure 1. Site Vicinity Map (Source: Rand McNally, 2019) The objective of the work reported herein is to evaluate the coastal impact to the subject lot over the next 75 years. Scope In order to accomplish the above-described objective, NOV A undertook the task-based scope of services described below. • Task 1: Establish Sea Level Rise. NOVA utilized the State of California Sea-Level Rise Guidance Update 2018 to research the anticipated mean sea level for the year 2094 (75 years). • Task 2: Determine Sea-Level Rise Impact to Proposed Construction. NOVA utilized available tide records for Newport Beach and compared them to the proposed finished floor elevations. 2 PA2019-102 Coastal Hazard Analysis Report 3904 River Ave, Newport Beach, California May 20, 2019 NOVA Project No. 3019035 • Task 3: Determine Flooding Hazards. Analyze existing data relating to flooding including El Nino conditions, coastal flooding, and tsunami inundation. • Task 4: Analyze Wave Runup. Assess the potential for wave runup based on site location. • Task 5: Analyze Erosional Hazards. Utilize the National Assessment of Shoreline Change Part 3: Historical Shoreline Change and Associated Coastal Land Loss Along Sandy Shorelines of the California Coast to determine the erosion rate per year. Geologic Coastal Hazards Figure 2. Site Aerial Photo (Source: Google Earth, 2019) The subject property is located adjacent to Newport Beach Harbor and is subject to geologic hazards including but not limited to sea-level rise, erosion, flooding, and wave runup. While it is understood that the sea levels have been rising over the past decades due to climate change, estimated rates of change in sea level are approximate and are influenced by an increase in sea water temperature. An increase in temperature of the ocean will cause the water to expand and will increase the rates at which the ice caps 3 PA2019-102 Coastal Hazard Analysis Report 3904 River Ave, Newport Beach, California May 20, 2019 NOVA Project No. 3019035 will melt, subsequently releasing stored water from the ice caps into the ocean. It is estimated by the year 2100 the sea-level rise ranges from 1 to 3 feet from existing mean sea level. The warming of the ocean water attributed to climate change may increase the intensity of the storms originating in the Pacific Ocean and bring with it an increase of wind, wave energy and precipitation. Sea Level Rise and Wave Run up NOVA utilized The State of California Sea-Level Rise Guidance 2018, developed by Ocean Protection Council, California Natural Resources Agency, and the California Ocean Protection Council that describes the best available science to support planning for sea-level rise in California. Table 28 taken from The State of California Sea-Level Rise Guidance describes a 66% probability of sea-level rise for high emissions in 2090 and 2100 for low risk aversion that is approximately 2. 9' after a straight-line interpolation for the year 2094, the estimated economic life of the structure. The highest tide of7.67' MLLW (7.49' NAVD88) with a wave runup correction of 0.3' for the project area will establish the bay water level of 10.39' NA VD88. According to the provided project plans, the proposed finished floor at the rear of the property is 9 .12' (NA VD88=8.94' MLLW) and is above the established Base Flood Elevation for the area. The proposed finished floor is 1.27' above the highest tide reached in Newport Beach (7.67' MLLW). It is estimated that by the year 2060 the highest high tide will reach near the finished floor elevation. It is recommended that a 16-inch concrete curb be installed at the top of building slab at the exterior wall locations bringing the top of curb elevation to 10.45' NA VD88. Areas where concrete curbs are not desired such as doorways can be temporarily protected with the utilization of sandbags. Flooding Hazard The subject property is located adjacent to Newport Bay and therefore the primary flooding hazard will come from sea-level rise. The existing Newport Bay water levels are reflected in the datum for the Newport Bay entrance (Datum 9410580) and is attached herein. Based on the provided plans, the top elevation of the existing seawall is 6.84' to 6.95'. It is recommended that the seawall be constructed such that the top elevation is not less than 10.0 MLLW to bring the top of seawall elevation in compliance with the current City of Newport Beach Waterfront Projects Guidelines and Standards. A higher elevation may be required by the City of Newport Beach pending design review. It should be noted that strong El Nino conditions under high tides may increase the risk of coastal flooding. Proactive measures to limit flooding should be considered and includes placing sand bags around building openings, design the finished floor elevations above the base flood elevations, and include a concrete curb designed at the perimeter walls. Bulkhead Seawall A recent site visit observed the seawall to be generally in good condition with the exception of a crack in the wall at the location where the deck and seawall are connected as depicted in the photo below. The seawall should be evaluated by a structural engineer and the increase in height requirements to bring the seawall to code should be designed by a structural engineer. 4 PA2019-102 Coastal Hazard Analysis Report 3904 River Ave, Newport Beach, California May 20, 2019 NOV A Project No. 3019035 Figure 3. Existing Seawall at 3904 River Avenue, Newport Beach Erosion Hazard Erosion refers to the cyclical long-term pattern defined by the loss or displacement of land along the coastline by wave runup, tidal forces, currents, wind and water born forces. Erosion hazard is a primary concern for properties developed along open ocean shores. The subject property is located along the Newport Bay, has a beachfront footprint that is stabilized and not subject to cyclical erosion as previously discussed. Review, analysis of historical aerial photographs and field observations of the subject site show no significant change to the shoreline in the last several decades. Typical cyclical erosion from wave runup is caused by boat wake and wind and is not subject to long-term erosion. The shoreline changes are not expected to change in the next several decades. The sea-level rise and the impact from climate change may increase the potential to accelerate shoreline erosion but it is not expected impact the structure. Tsunami Hazard The risk of flooding due to tsunami is considered low because of the absence of geologic conditions needed to generate a tsunami. A tsunami can be generated by sudden movement of the ocean's surface cause by plate tectonics, underwater landslides, volcanic eruptions. The location of the site, distance from the ocean shoreline, and the absence of the source of tsunami greatly reduces the likelihood of an impact from tsunami. In the event of a tsunami, likely originating from a great distance, would enter Newport Harbor and cause a small 1-to 2-foot wave that will dissipate as it travels throughout harbor and not have an impact 5 PA2019-102 Coastal Hazard Analysis Report 3904 River Ave, Newport Beach, California May 20, 2019 NOVA Project No. 3019035 to the site because of the adjacent developments. The likely occurrence of a tsunami impacting the site over the economic life of the structure should not be considered significant. Figure 3, attached below, shows the site in relation to the tsunami inundation area. Conclusion ?-n:WPORT BEACH KEY TO SYMBOLS ...r...-Tsunami Inundation Line Tsunami Inundation Area Figure 4. Tsunami Inundation Map It is not anticipated that flooding, erosion, tsunami, and sea-level rise will not significantly impact this proposed improvements provided the structural condition of the bulkhead seawall is evaluated and adequately raised so that the top of the seawall is raised to 10.0' MLLW and the 16" concrete curbs be installed at the perimeter wall locations while utilizing sandbags for building openings during severe flooding. If found that over the next 75 years the bulkhead seawall is inadequate to mitigate against a rising sea-level the bulkhead should be designed for an increase in height without encroaching seaward. Closure The opinions and conclusions included herein are based on the ex1stmg site conditions, proposed improvements, and projections of future sea-level rise. The conclusions and opinions have been developed 6 PA2019-102 Coastal Hazard Analysis Report 3904 River Ave, Newport Beach, California May 20, 2019 NOVA Project No. 3019035 in accordance with generally acceptable engineering principles and practices with inherent limitations of this study, NOV A makes no further warranty, either expressed of implied. Please call if you have any questions regarding the above. Respectively submitted, NOVA Services z:e~ Jes,3. ~84335 Carl D. Schrenk, CEG 900 CDS/spp:jdb Attachments: References Newport Bay Datum Projected Sea-Level Rise for Los Angeles Distribution: 4/ Addressee 7 PA2019-102 Coastal Hazard Analysis Report 3904 River Ave, Newport Beach, California References May 20, 2019 NOVA Project No. 3019035 Abrahamson, N., and Shedlock, K., editors, 1997, Ground motion attenuation relationships: Seismological Research Letters, v. 68, no. 1, January 1997 special issue, 256 p. American Society of Civil Engineers (ASCE), 2010, Minimum Design Loads for Buildings and Other Structures, ASCE 7-10. California Building Code (CBC), 2016 Edition. California Geological Survey (CGS), 1997, Guidelines for Evaluating and Mitigating Seismic Hazards in California, Special Publication 117. California Natural Resources Agency; California Ocean Protection Council; State of California Sea-Level Rise Guidance, 2018 Update. Cao, T, Bryant, W.A., Rowhandel, B., Branum. D., and Wills, C., 2003, The Revised 2002 California Probabilistic Seismic Hazard Maps, California Geologic Survey (CGS), June 2003. City ofNewport Beach, A Presentation on Newport Harbor's Base Flood Elevation (BFE) & Balboa Island Sea Wall Height, Community Development Department, Public Works Department. City ofNewport Beach Waterfront Project Guidelines and Standards, Harbor Design Criteria, Commercial & Residential Facilities, 2017 Edition. Frankel, AD., et al., 2002, Documentation for the 2002 Update of the National Seismic Hazard Maps, USGS Open-File Report 02-420. Federal Emergency Management Agency (FEMA) Mitigation Directorate, National Flood Insurance Program, Guidelines and Specifications for Wave Elevation Determination and V Zone Mapping, Final Draft, March 1995. NOAA Tides and Currents Datums for 9410580, Newport Beach, Newport Bay Entrance, CA Petersen, M.D., Bryant, W.A., Cramer, C.H., Cao, T., Reichle, M.S., Frankel, AD., Leinkaemper, J.J., McCrory, P.A., and Schwarz, D.P., 1996, Probabilistic Seismic Hazard Assessment for the State of California: California Division of Mines and Geology Open-File Report 96-08. U.S. Department of the Inteiror; U.S. Geologic Survey; USGS, National Assessment of Shoreline Change Part 3: Historical Shoreline Change and Associated Coastal Land Loss Along Sandy Shorelines of the California Coast, Open-File Report 2006-1219. Working Group on California Earthquake Probabilities, 1995, Seismic Hazards in Southern California: Probable Earthquakes, 1994-2024: Bulletin of the Seismological Society of America, Vol. 85, No. 2, pp. 379-439. www.seismicmaps.org, OSHPD Seismic Design Maps 8 PA2019-102 ✓~-~,:;\'- ) -~ C) -~ ,,.. .-.,·';.t' "~. V . -.,M~.,...-o"' # " . l., .Q !.k_ .:P ...... .,. < ;;.. ~ c; . ,· ., "'I· I --~I~ ft~:.:: ; J' ~ .. . ~ i:/ -·t=---J.t ;, - -----~ •• -::,;,;,· 1;·,. ..:··· 1:-:JI --':" -ro..,~·,.,~ •• ¥0.l.'···,: . --~o· . ~ >-~ - ..,,!::r,-..J ;!F,(6lco~-~q ·--~, (:'.,._\.I,; uJ:I. --~-· f. < . .,.V, ~--_-:,.::r.-·· ,r-• ---:1':~"'-~· . '. ~ ·-,• st-, ~-,; ~·---~ ~~.:z~-;ri,.,·?'it'"'~ ..... ;T=,,....,....,..·==,-,;;;,;;!Hoag i · ~s,...-,..,:':_ · :il.e-E ',:l~~., · --~ H~ -1:-!o°A.'~ -1:,1- (SOURCE: RAND MCNALLY 2019) ''Yo < ~-r,;,, ~ } ~ ..... <4 . S;,. "~ It· ❖~ ,"!t-., 1,,.. ·"'-= '-.!I ._,,. ·v";l'. ~t,._ ., ~'.l'" ;t h ~s , }; d0 · ;--~~o ~,...._.. 0 ~ '?I'}' • 0 ~'O,,_ ' ;'> •· .. ,~.~~~ i..l'"' ~ ·.,;: ~-- J;."-. ;o,. ct '1 ,. .-ta ' •. fr:..., ' Ne:• Harb Sci ·1rn --~ .w1. ·.u ,:?·~r.~~~'i; .... -. --~ . I ~-J: ·: ·, ',' !1 '' , ~ 1 /;· ,;. '..1f..-(-fiJj •,,·.' .i/.'." ,.i ) .'!; I if:; t,• ·'. _.•·, ,:Q,c "'-'Or/1.,s•·. ,; .:s; , • • • ., •. , , -~-~-:a -0n,.. •-' =-· :.'9,wt{. . // .. /· ,< .. ' ' ''' ).,~i ?_: -. O .. ;s . . Ou/J PA2019-102 0) 0 C\J I t-a: <1'. LU LU _J (9 0 0 (9 u..i (.) a: :::) 0 ~ PA2019-102 •:/ r:,'<-0~~ "~ ,._~e;, ('> 'f / ,._o'<-o <v" ~. ~ e;,-t" -bo J·,:·-, ··~ / 9.~ -~ er !8 v"°' ,i' r:,O ' e .c} (<.,~Xi ~<J ,:,,<v'<' <t- <J ,._;f'I \:f ,t"i' ~~,- ' o/.. er II It I s '· ,;r r~{:i~i:~:~ ;J~~,-.. ·i~:'. . .:t . ;<,. '.. . -·,,,.. ;, '-';1\~t, ... #,, .. , " -\( ·r ll le~ j (_, :~~·l ' # ., .. , ~;~;~ ' ,." • 1•, •,r.. ,Jl. '.'L'l,,,-,.,,,i, ,,• ii,;;:· '0, • ◊ , .. ._ ? S<h ._ f I ~.i. r'l«" .. T f•o•> :l•!~':i ,·~ ;W..te· , (.' .. ,. • "/4, f . . '.. . • . . ',JI$ • K.J-li~~ I' " ... .., . ;?,,y:p~;;;;: ·. / .. , ' ,,":,__ )~ , .-•11••~--·,.,-,,_,.;; ,,. •==~•~"1H•..1t,. 1-.J ,r, • ,-,, ' : .... ~--,;:-:-,•✓,~.., '~-;:~ ~ ' ', p;,~' ~~, ~ -7 ... ,~, ,,. / . "·{-' J•,f';., ~' . ·"-.,-, . ~}/::,~'::;~~¥· C. ¼ r, ~ ;; .• NE\HORT BEACH 0 C ~ ~ ~··v (SOURCE: CALIFORNIA EMERGENCY MANAGEMENT AGENCY 2019) ·•:~·{i;\(~ ?"f {~-' ~· ·~, .. r '"~ 'J''.:•1-:, ·,:.... ~ :,, . ,1 ~;: Jf.i:: -~: ., r ,.,.., 1·,,1,1., .. _ lt' \:•'!.f . _ ' \ .M ___ .. -.n_ .... · ·~-· •. 'YJ._ .· .. ,· ',i,"'J,J ' ,_.) ·~_J{f I ~ ·i ....'., iy•,11 I • :.Orona de! M PA2019-102 9410580 NEWPORT BEACH, NEWPORT BAY ENTRANCE, CA Home (/) I Products (products.html) / Datums (stations.html?type=Datums) / 9410580 NEWPORT BEACH, NEWPORT BAY ENTRANCE, CA Favorite Stations,,. Station Info,,. Tides/Water Levels,,. Meteorological Obs. Phys. Oceanography Current Datum Value: 3.33 Datums for 9410580, NEWPORT BEACH, NEWPORT BAY ENTRANCE CA NOTICE: All data values are relative to the MLLW. Elevations on Mean Lower Low Water Station: 9410580, NEWPORT BEACH, NEWPORT BAY ENTRANCE, CA Status: Accepted (Apr 17 2003) Units: Feet Control Station: 9410660 Los Angeles, CA T.M.: 120 Epoch: (/datum_options.html#NTDE) 1983-2001 Datum: MLLW Datum MHHW (/datum_options.html#MHHW) MHW (/datum_options.html#MHW) MTL (/datum_options.html#MTL) MSL (/datum_options.html#MSL) DTL (/datum_options.html#DTL) MLW (/datum_options.html#MLW) MLLW (/datum_options.html#MLLW) NAVD88 (/datum_options.html) STND (/datum_options.html#STND) GT (/datum_options.html#GT) Value 5.41 4.68 2.80 2.78 2.71 0.92 0.00 0.18 -3.33 5.41 Description Mean Higher-High Water Mean High Water Mean Tide Level Mean Sea Level Mean Diurnal Tide Level Mean Low Water Mean Lower-Low Water North American Vertical Datum of 1988 Station Datum Great Diurnal Range PA2019-102 Datum · M~ (/datum_options.html#MN) DHQ (/datum_options.html#DHQ) DLQ (/datum_options.html#DLQ) HWI (/datum_options.html#HWI) LWI (/datum_options.html#LWI) Max Tide (/datum_options.html#MAXTIDE) Max Tide Date & Time (/datum_options.html#MAXTIDEDT) Min Tide (/datum_options.html#MINTIDE) Min Tide Date & Time (/datum_options.html#MINTIDEDT) HAT (/datum_options.html#HAT) HAT Date & Time LAT (/datum_options.html#LAT) LAT Date & Time Tidal Datum Analysis Periods 01/01/1980 -12/31/1993 Value Description 3.76 Mean Range of Tide 0.74 Mean Diurnal High Water Inequality 0.92 Mean Diurnal Low Water Inequality 5.08 Greenwich High Water Interval (in hours) 11.15 Greenwich Low Water Interval (in hours) 7.67 Highest Observed Tide 01/28/1983 08:06 Highest Observed Tide Date & Time -2.35 Lowest Observed Tide 01/20/1988 16:30 Lowest Observed Tide Date & Time 7 .18 Highest Astronomical Tide 12/02/1990 16:06 HAT Date and Time -1.92 Lowest Astronomical Tide 01/01/1987 00:00 LAT Date and Time To refer water level heights to NAVD88 (North American Vertical Datum of 1988), apply the values located at National Geodetic Survey (http://www.ngs.noaa.gov/Tidal_Elevation/diagram.xhtml?PID=DX1968&EPOCH=1983-2001 ). Datums for 9410580, NEWPORT BEACH, NEWPORT BAY ENTRANCE, CA All figures in feet relative to MLLW e MHHW: 5.41 5 DHQ: 0.74 MHW: 4.68♦-------+--- PA2019-102 Showing datums for [ 9410580 NEWPORT BEACH ... Datum MLLW Data Units <!> Feet 0 Meters Epoch @ Present (1983-2001) 0 Superseded (1960-1978) Submit Show nearby stations Products available at 9410580 NEWPORT BEACH, NEWPORT BAY ENTRANCE, CA TIDES/WATER LEVELS Water Levels NOAA Tide Predictions (/noaatidepredictions.html?id=9410580) Harmonic Constituents (/harcon.html?id=9410580) Sea Level Trends (/sltrends/sltrends_station.shtml?id=9410580) Datums (/datums.html?id=9410580) Bench Mark Sheets (/benchmarks.html?id=9410580) Extreme Water Levels ( /esUest_station.shtml?stnid=9410580) Reports (/reports.html?id=9410580) METEOROLOGICAUOTHER Meteorological Observations Water Temp/Conductivity PORTS® This station is not a member of PORTS® OPERATIONAL FORECAST SYSTEMS This station is not a member of OFS PA2019-102 INFORMATION Station Home Page (/stationhome.html?id=9410580) Data Inventory (/inventory.html?id=9410580) Measurement Specifications (/measure.html) Information About CO-OPS (/about.html) Take Our Survey (/survey.html) Disclaimers (/disclaimers.html) Contact Us (/contact.html) Privacy Policy (/privacy.html) Products PORTS (/ports.html) OFS (/models.html) Tide Predictions (/tide_predictions.html) Currents (/cdata/Stationlist?type=Current+Data&filter=active) More about products ... (/products.html) Programs Mapping and Charting Support (/mapping.html) Maritime Services (/maritime.html) COASTAL (/coastal.html) More about programs ... (/programs.html) Partners Hydrographic Survey Support (/hydro.html) Marsh Restoration (/marsh.html) GoMOOS (/gomoos.html) TCOON (/tcoon.html) Revised: 08/08/2018 NOAA {http://www.noaa.gov) / National Ocean Service (http://oceanservice.noaa.gov) Web site owner: Center for Operational Oceanographic Products and Services https://tidesandcurrents.noaa.gov/datums.html?datum=MLLW&units=0&epoch=0&id=9410580&name=NEWPORT+BEACH%2C+NEWPORT+BAY+E... 4/4 PA2019-102 ! High emissions 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 7997 -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. Low Risk Aversion Medium· High Risk Aversion 2030 0.3 0.2 0.5 0.6 0.7 2040 0.5 0.4 0.7 0 .9 1.2 2050 0.7 0.5 1.0 1.2 1.8 Extreme Risk Aversion 1.0 1.7 2.6 low emissions 2060 o.8 o.5 1.1 1.4 2.2 High emissions 2060 1.0 o.7 u 1.7 2.5 3.7 Low emissions 2070 o.9 0.6 u 1.8 2.9 i High emissions 2070 1.2 o.8 1.7 2 2 3.3 5.0 r·-----------------------------<---------+-----~1----¼-----------------------------------· I tow emissions 2080 1.0 0.6 1.6 2.1 3.6 ! High emissions 2080 1.5 1.0 2.8 4_.3 _______________ ~~---------- i low emissions 2090 1.2 0.7 2.5 4.5 1-! H_ig_h_e_m_ls_sio_n_s __ 2090 -----~----------------18 ______________ __!_ ___ 1.2 _____ 3.4 5.3 8.0 1 low emissions 2100 I 1.3 0.7 3.o 5.4 i High emissions 2100 J 2.2 u 6.7 9.9 ! Low emissions lllO' 1.4 0.9 .--... --~.o 2.9 FOR i High emissions 2110' 2.3 1.6 3.3 YEAR 2094 11.5 r-------------------------~::---i-~::---r~-1----:;-:-r--;-;;---..;.;~~rl":;;--.---. 1 Low emissions mo I 1.5 o.9 2.5 I High emissions mo 2.7 1.8 3.8 5.o 8.3 -~----------------------------------------------------- : low emissions 2 2 1 1 3 3 0 0 i: 3 1 .. 1 0 ! 2 o .. 0 9 2.8 4.0 8.1 ! High emissions 4.3 5.7 9.7 13.8 16.1 i low emissions Zl40 1.8 0.9 3.0 4.5 9.2 L~~h emissions 2140 3.3 2.2 4.9 6.5 11.1 18.7 -low emissions 2150 1.9 o.9 3.3 5.1 10.6 7.3 12.7 21.5 *Most of the available climate model experiments do not extend beyond 2700. The resulting reduction in model availability causes a small dip in projections between 2700 and 2770, as well as a shift in uncertainty estimates (see Kopp et al. 2074). Use of 2770 projections should be done with caution and with acknowledgement of increased uncertainty around these projections. APPENDIX 3: SEA-UVE L RISE PROJECTIONS FOR All 12 TIDE GAUGES I 72 (SOURCE:STATE OF CALIFORNIA SEA-LEVEL RISE, 2018 UPDATE) 3904 RIVER NEWPORT BEACH, CALIFORNIA ,a~ -NOVA 24632 SAN JUAN AVENUE, SUITE 100 DANA POINT, CALIFORNIA Date: MAY 2019 Project No.: 3019035 PA2019-102