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2018-04-11 Minutes 11 April 2018 Meeting Minutes Chairman Barbour called the Port, Waterway & Beach Commission (PWBC) meeting to order at ~4:00. Participant introductions were made; the meeting’s attendance sheet is attached. The March 2018 meeting minutes were approved. Presentation One: Moffatt & Nichol Engineering (M&N) represented by Robert Neal and Dawn York presented an overview summary of the refined coastal modeling recently completed for the Wrightsville Beach (WB) Coastal Storm Damage Reduction (CSDR) Project. The team presented the five alternatives evaluated and brought forward a preferred. Alternative 5, with a uniform volumetric placement of 55% north and 45% south of Mercer’s Pier, is the recommended alternative. Alternative 5 (transects WB7.5-WB16.5) is the preferred placement scenario when evaluated and compared through: Morphological and Volumetric Sediment Transport (Delft3D Model) Shoreline Recession and Longshore Transport (GenCade Model) Cross Shore Storm Induced Erosion (SBEACH Model) Presentation Two: Staff presented an adaptive management approach evaluating potential beneficial placement of Mason Inlet maintenance dredge material along North Wrightsville Beach. The intent would be to augment the CSDR project’s northern transition zone through passive longshore transport from an updrift placement location. A motion was made, seconded and unanimously supported: “The PWBC supports technically assessing a potential beneficial placement option on North Wrightsville Beach in the next Mason Inlet relocation maintenance event (tentatively schedule in FY19).” A general question was posed followed by discussion. “Who approves the expenditure of New Hanover County Room Occupancy Taxes? Abbreviated Current Efforts: Wrightsville Beach’s Coastal Storm Damage Reduction Project The US Army Corps of Engineers (USACE) FY18 WB CSDR maintenance event is complete. The USACE’s final accounting is underway; the approximate pay volume was 763,000 cubic yards. Carolina Beach (CB) and Kure Beach (KB) FY19 CSDR Maintenance Projects The USACE has scheduled a plans and specifications status meeting at 10:00 on 17 April in CB Town Hall. Mason Inlet Relocation Project (MIRP) Gahagan and Bryant Associates (GBA) will begin the project’s 2018 surveying next week. Carolina Beach Inlet (CBI) In March, the USACE’s special purpose dredge Currituck removed 16,950 cubic yards of sand with management in the inshore dredge material management site (IDMMS). Chairman Barbour noted the USCG’s buoy tender Bayberry is scheduled to work next week in Masonboro Inlet followed by CBI. USACE surveys can be found at http://www.saw.usace.army.mil/Missions/Navigation/Hydrogrrahic-Surveys/Inlets=Crossings/ Shoreline Mapping Program The 2018 shoreline transect surveys (GeoDynamics) are complete. Following quality assurance and control, the data will be provided to M&N for engineering analysis. Refined Coastal Modeling (RCM) CB and KB analyses are underway; completions and presentations are anticipated this summer. Legislative Updates: The Fetzer Group continues efforts with FY19 asks and efforts toward a dedicated CSDR coast-wide funding mechanism. Many thanks to Rep. McElraft; she has been very engaged and helpful. Public Comment: Chairman Barbour noted the North Carolina Beach Inlet and Waterway Association’s (NCBIWA) Spring Meeting will be held at the NC Aquarium in Pine Knolls Shores on Bogue Banks, April 23 and 24. Please consider attending. Meeting Adjourned! WB2SIR WB7Duneridge WB17BlockadeRunner CrystalPierWB12Mercers WB10Sunspree Options: Alternative1?USACETemplate(WB9.5?WB16.5) Alternative2?ExtendSlightlyNorth(WB7.5?WB16.5) Alternative3?65%NorthofPier/35%South(WB7.5?WB16.5) Alternative4?ThinnerTemplate(WB4.5?WB20.5) Alternative5?55%NorthofPier/45%South(WB7.5?WB16.5) WrightsvilleBeachRefinedCoastalModeling April11,2018 WrightsvilleBeachRefinedCoastalModeling PotentialLocalManagementStrategiesforWBCSDR caseFederalParticipationFalters ProvidesBestAvailableEstimateonDesignOptions&Project PerformanceforaLocallyConstructedProject AssessesStormLevelofProtectionBenefits&Maintenance Frequency IncorporatesAnnualShorelineMonitoringDatatoHelpEvaluate PerformanceofPreviousCSDRMaintenanceEvents 2 WrightsvilleBeachRefinedCoastalModeling CurrentCSDRPlacementLimits&QuantitiestoDetermine IncreasedStormProtectionMayBeProvidedThroughDesign Adjustments. GenCade,DELFT3D,&SBEACHtoEstimateProject PerformanceandStormLevelofProtectionBenefits Delft3D?C◘ľĵℓśℓonSedimentTransport&Morphologic ChangesInfluencedbyLongtermCoastalProcesses GenCade?9ōĂ▄ĵĂĊśℓShorelineRecession&Longshore TransportBasedonMultiYearWavePatterns SBEACH?9ℓĊ╜▓ĂĊśℓCrossShoreStormInducedErosion ExpectedinExtremeWeatherEvents 3 WrightsvilleBeachRefinedCoastalModeling CSDRMaterialPlacementLimits 4 WrightsvilleBeachRefinedCoastalModeling DesignAlternatives15 PermitVolumesof500,000cy(A)&850,000cy(B) VariousTemplateOptions Alternative1?Ü{!/9Template(WB9.5?í.16.5) Alternative2?9ŝĊś■ŕSlightlyNorth(WB7.5?í.16.5) Alternative3?ﻲي?NorthofPier/35%South(WB7.5?í.16.5) Alternative4?Ç╙╜■■śŉTemplate(WB4.5?í.20.5) Alternative5?يي?NorthofPier/45%South(WB7.5?í.16.5) 5 WrightsvilleBeachRefinedCoastalModeling Alternatives15 6 WrightsvilleBeachRefinedCoastalModeling ShorelineRecession (GenCadeAnalysis) ComparestheShorelineChangeExpectedBetweenCSDRMaintenanceEvents. BasedonShorelineTrendsMeasuredBetweenSeptember2003&July2009. 7 RecessionRecession?Dś■/Ăŕś?Dś■/ĂŕśAnalysisAnalysis 1(5YearShorelineLocation) th Alt 1 (5Year Shoreline) th Alt 1 (Initial Shoreline) 8 RecessionRecession?Dś■/Ăŕś?Dś■/ĂŕśAnalysisAnalysis 2(5YearShorelineLocation) th Alt 2 (5Year Shoreline) th Alt 2 (Initial Shoreline) 9 RecessionRecession?Dś■/Ăŕś?Dś■/ĂŕśAnalysisAnalysis 3(5YearShorelineLocation) th Alt 3 (5Year Shoreline) th Alt 3 (Initial Shoreline) 10 RecessionRecession?Dś■/Ăŕś?Dś■/ĂŕśAnalysisAnalysis 4(5YearShorelineLocation) th Alt 4 (5Year Shoreline) th Alt 4 (Initial Shoreline) 11 RecessionRecession?Dś■/Ăŕś?Dś■/ĂŕśAnalysisAnalysis 5(5YearShorelineLocation) th Alt 5 (5Year Shoreline) th Alt 5 (Initial Shoreline) 12 RecessionRecession?Dś■/Ăŕś?Dś■/ĂŕśAnalysisAnalysis Structures(WB09) *WB09islocatedatScotchBonnettLn. 13 RecessionRecession?Dś■/Ăŕś!■Ă▄Ŧℓ╜ℓ?Dś■/Ăŕś!■Ă▄Ŧℓ╜ℓ Identification 14 RecessionRecession?Dś■/Ăŕś?Dś■/ĂŕśAnalysisAnalysis Summary/Conclusions: ShorelineClosesttoStructuresAroundWB09andWB14 ZoneMigratesbetweenWB1/2(ShellIslandResort)andWB13 (FayettevilleStreet)butismoreTypicallyLocatedaroundWB10 Inn) Alternative5isthePreferredAlternativeBasedonFinalShoreline 15 WrightsvilleBeachRefinedCoastalModeling SedimentTransport (Delft3DAnalysis) AnalysisComparestheVolumetricChangeExpected BetweenCSDRMaintenanceEvents. CalibrationBasedonVolumetricTrendsMeasuredBetweenMay2015&March2016. 16 ÇŉĂ■ℓ♫◘ŉĊ?5ś▄źĊى5ÇŉĂ■ℓ♫◘ŉĊ?5ś▄źĊى5AnalysisAnalysis Changes?í.ﮭﯾtoWB17,Alt15 17 ÇŉĂ■ℓ♫◘ŉĊ?5ś▄źĊى5ÇŉĂ■ℓ♫◘ŉĊ?5ś▄źĊى5AnalysisAnalysis Summary/Conclusions: VolumeChangeAndLongshoreTransportRateResultsIndicate NourishmentTemplatesWouldEvolveToQuasiEquilibrium ConditionsIn23YearsAfterPlacement LossesWithinTheProjectAreaForAlternative4(ThinTemplate) LargestAmongAllAlternativesAndConsideredToBeThe FavorableOption LossesAreWithin+/3%DifferenceForTheOtherAlternatives Alternative5IsthePreferredAlternativeDuetoMinimizedMaterial ConsideringNorthern&SouthernProjectBoundary 18 WrightsvilleBeachRefinedCoastalModeling CrossShoreStormResponse (SBEACHAnalysis) AnalysisComparestheCrossShoreStormResponseoftheDesignProfiles BasedonMultipleReturnIntervalStormEvents. onShorelineResponseFromHurricaneArthur&TropicalStormAna(2014?ﻮﮭوي?⁭ 19 ShoreShoreStormStormResponseResponse?{.9!/I?{.9!/IAnalysisAnalysis Protection(LOP)?{.9!/IExample 20 ShoreShoreStormStormResponseResponse?{.9!/I?{.9!/IAnalysisAnalysis Protection(LOP)?!▄Ċ5?يYrPostConstructionProfile th Return Interval Storm (YR) WB0910 WB1125 WB1425 WB1610 10 IntervalRepresentstheInverseoftheRespectiveStormEvents ofOccurrenceinanySingleYear.AsanExample,a5YRStorm a20%Chance(1/5)ofOccurrenceEachYear. 21 ShoreShoreStormStormResponseResponse?{.9!/I?{.9!/IAnalysisAnalysis Summary/Conclusions: AndWB14HaveThinnestShorelineWidth(LowestLOP)atthe MaintenanceCycle IncreaseLOPToAtLeastA10YrStorm 22 WrightsvilleBeachRefinedCoastalModeling ModelingSummary/Conclusions: IndicateaPotential$320MinDamagesMayResultin DiscontinuingCSDRMaintenanceEventsOvera15YearPeriod. 23 WrightsvilleBeachRefinedCoastalModeling ModelingSummary/Conclusions: ResultsIndicateThatAlt3(65%/35%)andAlt5(55%/45%)Are PreferableOptionsForIncreasingProjectBenefits isthePreferredAlternativeForIncreasingStormBenefits NorthernWrightsvilleBeachwhilestillMaintainingthe HighestLOPSouthofJohnnieaśŉľśŉ?ℓPier ModelingSuggest±15%ofPlacedMaterialVolumeShouldRemain ProjectAreaThrough5YearPostConstruction;However,a th ChangeintheMaintenanceIntervalisNOTRecommended 24 WrightsvilleBeachRefinedCoastalModeling Thankyou! Questions/Discussion 25 MasonInletRelocationProject MasonInletRelocationProject,CleanSweep GBA2015 ShoreProtectionApril,2018 County WrightsvilleBeach,CoastalStormDamageReduction 1938,WB 2015,NHC ShoreProtectionApril,2018 County Slide2 WrightsvilleBeach,2016CSDREvent WB NCDCM WB ShoreProtectionApril,2018 County Slide3 MasonInlet,Circa2002 NCDCM NCDCM ShoreProtectionApril,2018 County Slide4 MasonInletRelocationProject GBA ShoreProtectionApril,2018 County Slide5 F8 GBA 2017~OneyearPost2016Event NCDCM WaterwayApproach ShoreProtectionApril,2018 County Slide6 USACEFY18WBCSDR ShoreProtection County Slide7 LMG ShoreProtectionApril,2018 County Slide8 Questions LMG ShoreProtectionApril,2018 County Slide9 Agenda 11 April 2018, 4:00PM New Hanover County, Government Center Finance Conference Room, 500 4:00 Call to Order Welcome/Introductions Request approval of the March meeting minutes (emailed 16Mar2018). Presentation: Wrightsville Beach (WB), Refined Coastal Modeling Robert Neal and Dawn York, Moffatt & Nichol Engineering Presentation: Clean Sweep, Mason Inlet Relocation Project Staff Abbreviated Current Efforts: Wrightsville Beach (WB) FY18 Coastal Storm Damage Reduction (CSDR) Project Weeks’ Marine and their hydraulic cutterhead dredge McCaskillbegan sand placement on 11 Feb and finished on 16 Mar; final US Army Corps of Engineers (USACE) accounting is underway. Final placed volume ~763,000 cubic yards; planned volume, 715,000 cubic yards. Carolina Beach (CB) and Kure Beach (KB) FY19 CSDR Project The USACE is scheduling a preliminary planning meeting. Mason Inlet Relocation Project (MIRP) The MIRP’s 2018 project surveys will begin this month. Carolina Beach Inlet (CBI) TheCurrituck removed 16,950 cubic yards during the March maintenance event. Shoreline Mapping Program The 2018 field surveys are complete. Refined Coastal Modeling (RCM) The CB/KB modeling runs are in progress. Public Comment: Adjourn