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Home My WebLink AboutSS4 - Adapting to Sea Level Rise and Flooding - PowerPointAdapting to Coastal Hazards for January 22, 019 Residential Development tem No.SS4 5 City Council Study Session January 22, 2019 nuncil Dirpctic �. Continue with low-risk/high emissions scenario 2. assumptions ? Amend Zoning Code to allow accessory structures to increase in height? 3. Amend the Zoning Code to allow carports in the VE zone? 2019-01-22 Community Development Department - Planning Division Basis for addressing California Coastal Act 530253 New development shall do all of the following: (a) Minimize risks to life and property in areas of high geologic, flood, and fire hazard. 2019-01-22 Community Development Department - Planning Division 2019-01-22 Community Development Department - Planning Division Ek H istory of LoastF OldmINOR111r.1i 2019-01-22 Community Development Department - Planning Division Balboa Peninsula Unrkamed Tropical Storm of 1939 rti � $z i�lillian {199}�j+�� MMMMi4r1 {��QS) da rna a #o craps anrf sbr c#utes trom floading IL +145 pCOV10 {lied an shipS that � ■ «4 aaaeh were caught off guard by the � storm The anly known tropical I'I st-orm to directly hit s California !1� S .f :1 _ - ; 4 West Newport �y 2019-01-22 Community Development Department - Planning Division Newport Pier 2019-01-22 Community Development Department - Planning Division I Ab V 2019-01-22 Community Development Department - Planning Division 0 ZIA-11A %14�54 7J,1111 "I C `7 Tiv A-� Bill w;n -man Feet ee, L I CoSMoS-COAST Projections Initial MHW line (No SLR) Shoreline Projections Shoreline Projections Uncertainty City of Newport Beach: Reach 2 —0.8 it *SLR (2030) MHW Line 0.8 ft SLR (2030) MHW Line Uncertainty Shoreline Erosion Hazards 1.6 ft SLR (2050) MHW Line 1,6 ft SLR (2050) MHW Line Uncertainty -4.9 ft SLR (2100) MHW Line 4-9 ft SLR (2100) MHW Line Uncertainty .? in the Local Coastal Pronr;; 1 CLUP Coastal Hazards Policies (1.3 years old) Requires periodic SLR studies Implementation Plan Coastal hazard and geotech reports Site planning and subdivision design Min. slab elevation Appendix (Sea Level Rise) 2019-01-22 Community Development Department - Planning Division Added to address new CCC guidance Requires SLR be addressed Coastal development permits Future LCP amendments and updates Mirrors CCUs Sea Level Rise PolicyGuidance Requires use of "best available science" Requires future SLR vulnerability assessment 2019-01-22 Community Development Department - Planning Division 3est Available Science %` 2019-01-22 Ocean Protection Council (OPQ's Sea -Level Rise Guidance ■ Updated in March20:L8 ■ Based on new SLR projections Adds probability of SLR heights/rates Adds extreme SLR scenario (H++) Community Development Department - Planning Division MELTING ICE + b 2019-01-22 OF I THERMAL EXPANSION r� Community Development Department - Planning Division RISING SEA LEVEL Port of LA Tide Gauge 5096 probability High emissions 2030 0.595 probability sea -level rise meets 2040 sea -level rise meets sea -level rise meets • 2050 Low emissions 2060 or exceeds... 0.7 - High emissions 2060 Low emissions 2070 Risk Aversion Risk Aversion 3.0 High emissions 2070 Low emissions 2080 2.2 3.1 High emissions 2080 Low emissions 2090 3.6 1.8 - High emissions 2090 Low emissions 2100 2.0 4.3 High emissions 2100 Low emissions 2110' 2.2 4.9 High emissions 2110# Low emissions 2120 2.4 5.4 High emissions 2120 Low emissions 2130 High emissions 2130 Low emissions 2140 High emissions 2140 Low emissions 2150 High emissions 2150 5096 probability 5596 probability 596 probability 0.595 probability sea -level rise meets sea -level rise sea -level rise meets sea -level rise meets • or exceeds... is between... or exceeds... or exceeds... 0.7 - Law Risk Medium - High Extreme 1.2 - Aversion Risk Aversion Risk Aversion 0.3 0.5 0.7 0.8 1.0 0.9 1.2 1.0 1.5 1.2 1.8 1.3 2.2 1.4 2.3 1.5 2.7 1.7 3.0 1.8 3.3 1.9 3.7 0.2 0.5 0.6 0.4 0.7 0.9 0.5 1.0 1.2 0.5 1.1 1.4 0.7 1.7 0.6 LOW 1.8 0.8 - 2.2 0.6 - 2.1 1.0 - 1.8 2.8 2.5 0.7 - 2.7 3.4 1.2 - 0.7 - 2.1 3.0 1.3 - 3.2 4.1 0.9 - 2.2 3.1 1.6 - 3.3 2.5 4.3 0.9 - 3.6 1.8 - 3.8 2.8 5.0 0.9 4.0 2.0 4.3 5.7 4.5 0.9 3.0 2.2 4.9 6.5 0.9 3.3 5.1 2.4 5.4 7.3 0.7 1.0 1.2 1.7 1.8 2.6 2.2 MEDIUM - HIGH A 3 L 4.5 8.0 9.9 I 5.3 5.4 6.7 6.0 7.1 11.5 7.1 8.3 1?.r 8.1 9.7 1;_ 9.2 11.1 10.6 12.7 LOW z.7' to 3.2,' MEDIUM ' to 6.7' HIGH R'ta 130 d 25 II 20 II 15 II NOI 201 7■2 wat 2038 2058 "Business as Usual" Scenario 2094: 75 -Year HIGH ^8.' 2078 2o98 2118 2138 =Low —*--Medium High 419.9 r 22.6 Protective devices placed at openings to protect the structure. 1 11 Bulkhead elevations up to 10.1' Flood protection curb up t0 10.1! Finished floor constructed to q.oI 2roTs'ro ■:fT1'1T: ' I!■� �1��1 �Dd 4 Bulkhe 10. 1' N, Existing Bulkhel 03" C;iiardraiI 2019-01-22 Community Development Department - Planning Division T.C. io.1' NAVD88 F.F. g.o' NAVD88 Existing Grade TMOTA Bulkhead adaptation Higher/reinforced bulkheads Accessory structures 2019-01-22 Coastal access Coastal views WITH HIGHER SLF Site and Building Design Higher pad elevations? Open Foundations (stilts)? Higher height limits? Community Development Department - Planning Division awcessory Structure Amend Zoning Code to allow accessory structures to increase in height? ti �• F�LS�� 2019-01-22 Community Development Department - Planning Division Assumption of additional flood risk California Coastal Commission acceptance? Guidance document suggests medium-high risk aversion probabilistic projection. LCP Decertification??? If we take no action to account for sea -level rise for CDP applications. 2019-01-22 Community Development Department - Planning Division Use the "low-risk aversion" probabilistic projection (66% probability) Use "Business as usual" scenario (RCP 8.5, high emissions scenario) Proceed with current approach for CDPs associated with private development projects 2019-01-22 Community Development Department - Planning Division Where does FEMA flood map fit of this? 2019-01-22 into all Community Development Department - Planning Division 48th Street W Properties Affected by VE Zone Properties Affected by VE Zone ( 166 ) 0 24th Street U L --- I ■IIINI !I- iIIIN�lllll II�III I�IN�II IINIIII �1� 111111 IIIIN, III, Toward Flood Source 100 -Year BOttDM Of Wave Crest Lowest Horizontal Elovatle n (B F E) Structural Member Fre eh -Gard ,. -- -- ---- --- --- -- ------ - ---- - ------ -- -- _ 10 -Year Shilwafter sevation Exceeding NFIB Elevation Requirements in Costal A Zones and w Zones 2019-01-22 Community Development Department - Planning Division FEMAVE Flood Zone SEW PART m Res, iltinq Design Changec... Cq� FpFN�P Existing Design FEMA Compliant Design * 7y To% 29, 29 33' Finish f Floor BFEIFZ ' 16' Existing Grade 12' I Existing Grade 12' I 2019-01-22 Community Development Department - Planning Division !\ J1FTiT.ii 0 rz-1.i an GN The effective date of the revised FIRM is March21,2019. The City is going to Hold a public outreach with FEMA representatives to discuss the FIRM compliance. 2019-01-22 Community Development Department - Planning Division nuncil Dirpctic Continue with low-risk/high emissions scenario assumptions ? Amend Zoning Code to allow accessory structures to increase in height? Amend the Zoning Code to allow carports in the VE zone? Any other changes? 2019-01-22 Community Development Department - Planning Division For more information contact: Patrick Alford, Planning Manager Makana Nova, Associate Planner Samir Ghosn, Deputy Director 949-644-3235 949-644-3249 949-644-3277 palford(a)neportbeachca.gov mnova Onewportbeachca.gov sghosn(a)newportbeachca.gov www.newportbeachca.gov www.newportbeachca.gov www.newportbeachca.gov