PacificCoastCongressofHarborMaster&PortManagers

“Getting It Done” •  TheCrescentCityHarborhasalonghistoryofdamageanddestruc7onfromtsunamis.

•  Thecityexperiencedtsunamicondi7ons317mesbetween1933and2008

•  In1964,12peoplewerekilledand19blocksofthedowntownareawasdestroyed.

•  Todaywe’lldiscusshowtheharborrecoveredfromthe2006and2011tsunamis

Presenters:

•  EllenJohnck,EllenJohnckConsul7ng

•  PatrickBailey,CrescentCityHarborDistrictBoardofHarborCommissioners

•  CharlieHelms,CEO/Harbormaster,CrescentCityHarborDistrict

•  AnitaYao,Wharfinger,PortofSanFrancisco

The 2006 Round of Destruction started on November 15

2006 Tsunami •  The2006tsunamidamagedtheharborbutthetrueseverityofthedamageswerediscoveredoveraperiodofmonths

•  Theoriginaldamagees7matedidnotqualifytheeventforFederalAssistance

•  TheHarborDistricthadtofindawaytoraise$5milliondollarstocoverit’sshareoftherebuild

• CALOfficeofEmergencyServicesdidnotwanttoupgradetheharbor–theirgoalwastoputitbackthewayitwas

•  Theywouldpayforalimitedamountofhazardmi7ga7on–upto15%ofprojectcost

• HoweverCALOESwouldpayforupgradesrequiredbycodesandstandards

The question was “What are the Codes and Standards for Marina design in a

tsunami zone?” Theanswer:NONE!

•  Therewerenostandardsfortsunamisin2006buttherewereguidelinesforHurricanes

•  Thedesignreturnperiodonhurricanesshouldbebalancedagainsttheexpectedlifeofthemarina,andcompliancewithlocalcodesandordinances.Keepinmindthatcodesareminimumdesigncriteriaandincreasedstrengthandreliabilitymaybemoreeconomicalinthelongrun

•  Therecommendeddesignperiodforhurricanes(windand7dalsurge)isnormally50years(2%probability,inanygivenyear)and25years(4%probabilityinanygivenyear)shouldbeconsideredtheabsoluteminimumdesignperiod.Thisistrueeveniftheexpectedlifeoftheoffshorefacili7esislessthan25years.

Ben C. Gerwick / COWI Tsunami Study

•  TheHarborDistrict,inanefforttosupportit’sasser7onthatthemostefficientwaytorebuildtheharborwastousethe50yearHurricanestandard,hiredtheBenC.Gerwickengineeringgroup,nowapartoftheCOWIorganiza7on,toconstructapredic7vemodelfortsunamiflowintotheCrescentCityHarbor

•  TheHarborwantedevidencethatitcouldusetoconvincetheCALOfficeofEmergencyServices(CALOES)thatrebuildingtheharbortoafifyyearreturnstandardwouldactuallybemorecostefficientthanjustreconstruc7ngthemarinatoitspriorstate

Ben C. Gerwick/COWI Study Results •  Thepreviousslidesshowthepredictedflowandvelocityofatsunamisimilartothe2006tsunamiintheCrescentCityHarbor

•  Flowsofover6meterspersecond(11.6knotsor13.4milesperhour)arepredictedalongtheseawallatthemouthoftheharbor

•  Thehighvelocityflowcon7nuesintotheharboritselfandbringsitsfullforceonto“H”dockandcon7nuestobaier“G”and“F”withsimilarforce

•  Thedestruc7vethenflowsthroughouttheharborinagenerallyclockwiseflowatreducedveloci7es

Ben C. Gerwick/COWI Code Findings • Bri=shCode(BS6349-1:2000):“Normallyadesignworkinglifeoftheorderof50yearsisexpected”

• AustralianCode(as3962-2001):"Strengthlimit-stateloadsshouldbecalculatedfora1ina50yearreturnperiodforwind,wave,surgeandfloodingloads“

•  EM(1110-2-1615):"Theeconomicdesignlifeofmostsmallboatprojectsis50years"

•  EuropeanCode(R46):For"portinstalla7onsfor(…)industrialopera7ons(…)only25years[designservicelife]canbefiguredon"

2006 to 2011 •  TheHarborDistrictwasabletosecureaCommunityDevelopmentBlockGrant(CDBG)for$5millionwhichwasusedtocovertheharbor’s25%costobliga7onforitsshareofthe2006tsunamirepairs

•  ThegrantwasawardedtotheHarborsothattheDistrictcoulddemonstratetheeconomicimpactthefishingfleetandassociatedbusinesseshadonthecounty

•  Inthemean7me,theHarborDistrictthroughitsDistrictEngineer,StoverEngineering,filedforthepermitsneededtobegintheharborrebuild

•  StoverEngineeringmanagedthedesignandpermiqngprocess

•  ThepermitspathwayconformedtotheCALOESstandardofrebuildingtheharbortoitsformercondi7on

The Harbor’s reconstruction permit was issued in late February 2011 – just a few

weeks before the Harbor was completely destroyed

S7llstakenfromUSCGvideofilmedduringthetsunamievent

The flow pattern of the 2011 tsunami was an amazing match to what was predicted in the Ben C. Gerwick/ COWI Study

S7llstakenfromUSCGvideosfilmedduringthetsunamievent

Following the 2011 tsunami devastation, the California Coastal Commission put the rebuild debate to rest by mandating that a fifty year

tsunami resistant harbor be constructed

To meet the fifty year standard, pilings were upgraded from 16 inch diameter to 31 inch diameter pilings which

were driven into bedrock

The Bellingham Marine Unibolt concrete dock system was selected for the new harbor

After dredging operations were completed in the Inner Boat Basin, the Outer Boat Basin and the federal channel were dredged while the Inner Harbor was being reconstructed

Surge suppression dock at Harbor entrance (Photo courtesy of Bellingham Marine)

View of Inner Boat Basin Piling Frequency (Photo courtesy of Bellingham Marine)

Viewfacing“H”Dock(PhotocourtesyofBellinghamMarine)

The West Coast’s First Fifty Year Tsunami Resistant Harbor The Crescent City Harbor District

(Photo courtesy of Bellingham Marine)