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CityofSouthPadreIsland

ErosionResponsePlan

SubmittedtotheTexasGeneralLandOffice

InCompliancewith31TAC15.17

ApprovedforSubmissionJune20,2012

Preparedby:PeterA.Ravella,Principal

PeterA.RavellaConsulting,LLC

BillWorsham,P.E.LEAPEngineering

RoyE.Mann,PrincipalTheRiversStudio,LLC

ReubenTrevino

CoastalResourcesManager

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TABLEOFCONTENTS1. OVERVIEW

1.1. Purpose1.2. JurisdictionalScope1.3. Requirements‐TNRC§33.607,31TAC§15.171.4. ProcessforReview,Approval&Implementation1.5. ERPShorelineDataSources

2. CURRENTSHORELINEMANAGEMENTPRACTICES

2.1. PeriodicNourishment/BeneficialUse2.2. DuneEnhancement/DunePlantingProgram

2.2.1. 2010/11Plantings2.2.2. 2011/12Plantings2.2.3. Volunteersreport

2.3. SeaweedManagement2.3.1. Goal2.3.2. CircumstancesWarrantingSeaweedRelocation2.3.3. Timing2.3.4. LocationandBeachConditions2.3.5. Seaweedcoverage

2.4. ManagementofRelocatedSeaweed

3. EXISTINGSHORELINECONDITIONS

3.1. Beach&BeachProfile3.1.1. Shorelinechangerates3.1.2. Annualvolumelossesandgains3.1.3. AreasofConcern

3.1.3.1. HotSpots3.1.3.2. Developed&UndevelopedBeachfrontTracts3.1.3.3. Vulnerability

3.2. DuneComplex&Uplands3.2.1. Location,elevation&depth3.2.2. Vegetativecover3.2.3. Dunehotspotsandwashoverareas3.2.4. Conclusions

3.3. BeachAccessHandbook(AttachmentA)

4. DESIREDSHORELINECONDITIONS

4.1. Beach&BeachProfile

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4.1.1. Goal:BeachDepth&Elevation4.1.2. SandVolume&Sources4.1.3. Methods4.1.4. EstimatedAnnualCost

4.2. DuneComplex&Uplands4.2.1. Goal:Location,Elevation,Depth&VegetativeCover4.2.2. SandVolume&SandSources4.2.3. Methods4.2.4. EstimatedAnnualCosts

4.3. BeachAccessPoints4.3.1. AccessEnhancementGoals4.3.2. Walkovers&Mobi‐mats4.3.3. ConceptualWalkways&Footpaths4.3.4. EstimatedAnnualCost

5. SEMIANNUALPRE‐STORMMONITORINGPROGRAM

5.1. Goal–MaintainFEMAReimbursementEligibility5.2. Frequency,MethodandLocation5.3. OutputReport/Recordkeeping5.4. EstimatedAnnualCost

6. EROSIONRESPONSEPLANFORSPICITYLIMITS

6.1. Setbacks6.2. ProhibitionOnConstructionSeawardofSetbackLine6.3. ExemptionsfromSetbackLine6.4. RequirementsforExemptConstruction6.5. ProcedurestoPreservePublicAccess6.6. ProceduresforDuneProtection&Enhancement6.7. CriteriaforVoluntaryAcquisitionorBuyouts

7. CONCEPTUALFUNDINGSTRATEGYFORERP

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SOUTHPADREISLANDEROSIONRESPONSEPLAN

1.0 OVERVIEW

Recognizing the long‐termbenefits of effective shorelinemanagement, the City ofSouthPadrehaselectedtoprepareandimplementanErosionResponsePlan.

1.1Purpose

Inaccordancewithstatelaw,theCityofSouthPadreIslandhaselectedtoprepareanErosionResponsePlan.Ingeneral, thepurposeofthisplanistoexploremeansand methods to reduce the public expenditures due to damage to property andinfrastructurethatcanresultfromshorelinechange,erosion,andstormconditions.

In2009, theTexasLegislaturepassedHouseBill 2571whichmandated that eachcoastalcommunitydevelopanErosionResponsePlan(ERP).While this legislativedirectiveis“voluntary,”citiesandcountiesthatfailtoprepareanERPareineligiblefor state assistance under certain grant programs such as the Coastal ErosionPlanningandResponseAct.ItisinthebestinterestoftheCitytodevelopanERPinaccordancewiththestatuteandtheregulatoryrequirementsfoundinTexasNaturalResourcesCode,§33.607andChapter31,TexasAdministrativeCode,§15.17et.seq.

1.2ScopeofthePlan

Inthisplan,theCityofSouthPadreIslandhaselectedtoaddresserosionsandstormriskswithin the currentCityboundaries. Subsequent editionsof theERPmaybeaddedtoaddresspotentialrisksintheundevelopedareasnorthoftheCityinwhatiscalled its“extraterritorial jurisdiction”orETJ.TheCityrecognizesthatCameronCountycurrentlyhasprincipaljurisdictionoverbeachanddunemattersintheETJ,however, because it is likely theCitywill annexportions of theETJ in the future,developmentinthisareamayleadtosignificantfinancialexposuretotheCityandits taxpayers from poor development practices and predicted storm damage andshorelineerosion.

1.3ERPRequirements

ThedetailedrequirementsforlocalErosionResponsePlansaresetforthinChapter31TexasAdministrativeCode,§15.17. Ingeneral, the rules require that theERPaddressthefollowingelements:

Constructionsetbacklimits Prohibitionsonconstructionseawardofthesetbackline Exemptionsfromthesetbackline Requirementsforexemptconstruction Procedurestopreservepublicaccess Proceduresforprotectionandenhancementofdunes Criteriaforvoluntaryacquisitionorbuyout

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Post‐Stormrecoveryplans

1.4 ProcessforERPDevelopment,AdoptionandCertification

Theprocessforthedevelopment,adoption,andcertificationoftheCity’sERPissetforth in the General Land Office (GLO) rules governing the program. LocalgovernmentsarechargedwiththeresponsibilitytodevelopanERPindraftformforsubmissiontothestatenolaterthanJuly2011.

Upon submission to the state, the GLO will review the Draft ERP and providecomments to the City. The City will then have the opportunity to undertakenecessary and appropriate revisions to the Draft, leading to the submission of aFinal ERP. Once in final form, the Citywill be required to include the Plan as anappendixtoitsexistingBeachAccessandDuneProtectionPlan.

Following local adoption, the GLO will review the ERP for final certification inaccordance with state procedures. To do so, the GLO is required to propose anadministrative rule to either reject or certify the City’s plan. The proposedcertification is published in theTexasRegister followed by aminimum of 30‐daypubliccommentperiod.Assumingacceptablepubliccommentsandcompliancewithallregulatoryrequirements,theGLOcanthenmoveforwardwithfinalcertificationoftheCity’sERPintheformofafinaladministrativerule.Thecertificationprocessmayrequireupto180daystocomplete.

Once certified, theCity is then required tomove forwardwithamendments to itsBeach Access and Dune Protection Plan and ultimately to implementation of thecertifiedERP.Thiscompletestheadoption,approval,andcertificationprocess.

1.5 ERPShorelineDataSources

IndevelopingitsCity’sERP,theCityreliedonthreeprincipaldatasources:(1)theUniversityofTexasBureauofEconomicGeology (UT‐BEG); (2) theTexasGeneralLandOffice;and(3)dataavailable throughtheCity’sbeachmanagementprogramarchives.Shoreline change rates, beach profiles, and projected shoreline positions wereobtained from the UT‐BEG. From the GLO, the City obtained the 2009 TexasCoastwideErosionResponsePlan,whichincludessubstantialdataandinformationnecessaryforthelocalplan,LIDARelevationdata,andupdatedaerialphotographyof theCity’s shoreline. Finally, theCity compileddataonpreviousbeneficialuseprojects,updatedshorelineprofiles,duneenhancementprojects,andcostestimatesforvariousshorelinemanagementactivities. NonewsurveydatawascollectedinthefieldduringthecourseofdevelopingthisERP.2.0 CURRENTSHORELINEMANAGEMENTPRACTICES

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2.1PeriodicNourishment/BeneficialUse

Formorethantenyears,theCityhasworkedwiththeU.S.ArmyCorpsofEngineersto place sand dredged from the federallymaintained Brazos Santiago Pass on itsbeaches. Thisbeneficialuseproject isa critical componentof theCity’s shorelinemanagementprogramandwillremainacornerstoneoftheERP.Table 1 shows the history of beneficial use projectswithin the City, beginning in1997andextendingthroughMarch2011.Thebeneficialuseprojectsareshadedinorangeandconstitutethelargestsourceofsandvolumeplacedonthebeachduringthe reporting period. Over the 14 years, total sand volume placed reached2,774,390cubicyards.Projectcostsforalleffortsidentifiedtotaled$18,885,015,withtheCityassuming$1,636,832ofthecost.Theremainingcostswerepaidbythestateorfederalgovernment,dependingonthespecificprojecttypeandthefinancialarrangementsmadeamongtheparties.

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Table 1: City of South Padre Island Renourishment History Note: Beneficial Use Projects are in Orange

Project Date

Sand Source Project Location Project Length

(ft)

Fill Volume (cu yds)

Cost of Project

Cost to City

Feb 1997 Dredge Brownsville Ship

Channel 3.5 - 4.5 mi from Jetties; Padre S north to Suntide

8,100 489,211 $1,938,700 $661,259

Feb 1999 Dredge Brownsville Ship

Channel

1.5 - 2.25 miles from Jetties; Radisson N to

Padre Grand 4,600 494,766 $3,136,170 $55,388

May 1999 Highway 100 Sand Tiki south to Inverness 3,200 41,628 $48,500 $22,565

Dec 2000 Dredge Brownsville Ship

Channel Bahia Mar S to Starlight

Circle beach access 5,200 366,886 $2,277,893 $177,314

Feb 2001 Highway 100 Sand

Tiki south to Inverness 3,200 27,956 $107,200 $3,200

Jan 2002 Highway 100 Sand

Tiki south to Inverness 3,200 23,895 $109,917 $3,125

Nov 2002- Jan 2003

Highway 100 Sand La Quinta/City limits S to

Inverness 3,800 81,252 $37,644 $9,411

Nov 2002 Dredge Brownsville Ship

Channel Neptune Circle N to Gay

Dawn Circle 2,400 306,402 $2,946,400 $183,210

Dec 2003 Highway 100 Sand La Quinta/City limits south

to Inverness 3,800 53,560

Nov 2004 - Jan 2005

Dredge Brownsville Ship Channel

Neptune Circle N to Gay Dawn Circle

1,200 261,600 $1,495,000 $84,525

Feb - Mar 2007

Highway 100 Sand La Quinta/City limits S to

Good Hope Circle 4,400 71,045 $432,133 $108,033

Feb - Mar 2008

Highway 100 Sand

La Quinta/City limits S to Inverness 3,800 100,178 $528,545 $132,136

Dec 2008 – Mar 09

Dredge Brownsville Ship Channel

Gay Dawn Circle to White Sands

2,200 406,000 $5,600,000 $139,938

Mar 2009 Highway 100 Sand White Sands to La Quinta/ City Limits 900 50,011 $226,913 $56,728

Mar 2010 Dredge Brownsville Ship

Channel

Parkshore to N of La Quinta 2500 130,000 $1,839,222 $138,750

Mar 2011 Dredge Brownsville Ship

Channel Northern City Limits 2500 367,000 $4,017,000 $600,000

Totals

2,774,390 $18,885,015 $1,636,832

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2.2DuneEnhancement/DunePlantingProgram

In2009,theCityinitiatedaDuneEnhancementandPlantingProgramtorespondtodunelossesfollowingHurricaneDollyandHurricaneIke.Thisprogramhasevolvedand grown to become an integral element of the City’s shoreline managementprogramandacornerstoneoftheErosionResponsePlandescribedinthisreport.

ThepreservationandrestorationofthedunelineprovidesmanybenefitstotheCityand its residents. Land Commissioner Jerry Paterson succulently articulated thevalueofdunesintheagency’sDuneProtectionManual:

“TheTexas Coast is an environmental and economic treasure composed ofinterlocking, interdependent ecological systems. Coastal sand dunes are acrucial part of that system. Dunes serve not only as vital habitat fornumerous native plants and animals, but an irreplaceable recreationalresourceuponwhichhumansmusttreadlightly.”

Mostbeachfrontpropertyownerstodayunderstandthatthedunelineprovidesaneffectivenaturalbarriertoerosion,flooding,andstormdamagethatprotectspublicand private property, including inland infrastructure. In addition, visitorsappreciatethatthedunesystemprovideshabitatforlocalplantsandanimals.Itisgenerallywellunderstoodthathealthydunescreatea“sandsavingsaccount"forthebeach itself.Whileaseawallorotherhardstructurescanundermine thebeach ‐‐because they focus and refractwave energy back to the sandy beach ‐‐ a healthydune system can better absorbwave energy and provide a source of sand to thebeachwhenitisunderwaveattack.Sandthatisstoredinthedunesisbeneficialtothe function and stability of the beach. During storms, dune sand can beredistributed down the beach face by wave attack and erosion, where summercurrentscanmoveitbacktobeachface. This“sandcycle”iswelldescribedintheGLODuneProtectionManual:

“Duringastorm,high‐energywavesflattenthebeach.Waveswashingagainstthe base of the foredunes erode sand, undermining and collapsing theseaward dune face. In severe storms, the dune face commonly recedesseveral yards— inextremecasesasmuchas100yards— leavinga steepcliff.Sometimesdunesarecompletelydestroyed.Retreatingwavescarrytheeroded sand offshore and deposit it just seaward of the surf zone in largebars. Thisprocess of dune erosion and sandmovementdissipatesmuchofthe energy of stormwaves. Sandbars also dissipate stormwave energy bycausingwavestobreakfurtheroffshore.

If the supply of sand remains constant, the natural exchange between thebeach, dunes, and offshore areaswill repair and rebuild dunes to a height

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andwidth determined by local conditions. However, the loss of vegetationthat traps andholds sandmakes the beach anddunesmore susceptible towind andwater erosion, thus inhibiting their recovery from storms. Bays,channels, marshes, and grass flats behind the weakened foredune areexposed to storm‐surge flooding and to accumulation ofwindblown sand.”(DuneProtectionManual,Chapter2,page5).

Startingin2008,theCityofSouthPadreIsland,incooperationwiththeSouthTexasSurfrider Foundation South Texas Chapter and University of Texas Brownsville(UTB),initiatedapilotprojecttoharvestduneplantsfordunerestorationprojectsfollowingHurricanesDollyandIke.HarvestedplantsweretransportedtotheUTBgreenhouse where they were propagated and eventually replanted on the City’sdunes as part of the post‐hurricane recovery effort. While this modest pilotprogram planted a few thousand plants here and there, it demonstrated that theparties could cooperatively work together and that dune plantings could besuccessfulycompleted,leadingtoamoreorganizedandcomprehensiveeffort.

2.2.12010/11Plantings

In2010,theCitydevelopedamoreaggressivedune‐plantingschedulewiththegoalof8,000to10,000plantsperplantingevent.PlantingprojectsstartedinDecember2010andwerescheduledonceamonththroughMay2011,withthespecificgoalofinstalling approximately 50,000 plants along the most narrow and vulnerablesections of the City’s beaches. As the program expanded, property owners andhomeowner associations raised concerns that the dune enhancement/plantingprojects could elevate the dunes, blocking the view from ground‐level condos orrooms.However, but constructivelyworking through these issues,many of theseconcerns have been resolved. Many property owners recalled that even thoughHurricaneIkemadelandfallintheGalveston,Texasarea,morethan300milestothenorth,thestormproducedsignificantstormsurgeanddunedamageinSouthPadreIsland.Presently,thereisgreaterappreciationfortheduneenhancement/plantingprogramandincreasinglandownerdemandforprojectsalongtheCity’sbeachfront.

The dune enhancement and planting program has been successful. Over the lastyear, the vegetation planted by the volunteers has becomemore established and,mostimportantly,monitoringhasshownthattherootsystemshaveextendedintothedunes,increasingtheirstability.StartinginDecember2010,theCityhostedoneSaturdaymorningvolunteerplantingeventseachmonthuntilMay.Inall,morethan400 volunteers have participated in the program from various organizationsincluding students from South Texas College and the University of Texas atBrownsville, TexasMaster Naturalists, winter visitors, island locals, and studentsfromschooldistrictsacrosstheRioGrandeValley.Morethan350localelementaryschoolkids fromthe3rd,4th,and5thgrade levelshaveparticipatedthroughschoolfield trips to the beachwhere theywere taught the importance of the dunes andgivenachancetohelpplantdunevegetation.

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Since the program’s inception, the City purchasedmore than $21,000.00 of duneplants and, with the help of the volunteers, was able to substantially reduce itsinstallationcosts.Todate,volunteerhavedonatedapproximately2,100man‐hourstotheprogram,savingtheCityapproximately$50,000.00inlaborcosts.

2.2.22011/12Plantings

The City and the Surfrider Foundation South Texas Chapter hosted 7 volunteereventsandschoolfieldtripforthe5thgradersofalocalelementary.Togetheratotalof50,000indigenousplantswereplantedinbareareasthatwere lowinelevationandvulnerable.

2.2.3VolunteerReports

Thevalueoftheseduneenhancement/plantingprojectsgoesbeyondthenumberofvolunteers,theplantsinstalled,oreventhesizeofthedunearearestored.Certainly,theprojectshaveapositiveenvironmental,ecologicalandeveneconomicimpact,asdifficultasitmaybetoquantifythesebenefits.Throughthisprogram,theCityandits partners are also changing the community’s ethic and enhancing the public’sunderstandingofbeachanddunesystem.TheCityhasbrought togetherdisparategroupsfromaroundtheregionandgiventhemanopportunityto investtheirtimeandenergyinthebettermentofSouthPadreIsland’sbeaches.Intheprocess,thesevolunteers are educated about the function and value of ahealthybeach/dunesystem. Participants unavoidably gain a vested interest inthe protectionandmaintenance of the island’s beaches and dunes, an investment that cannot bemeasuredindollarsorstatistics.TheSPIDuneEnhancementandPlantingProgramhashelpedcreateamoreeducated,caring,andmotivatedbeachcommunityanditishoped theparticipating volunteerswill share their knowledge and their desire toprotectourlocalbeacheswithothersformanyyearstocome.

2.3SeaweedManagement

Over the years, the City has developed a set of guidelines governing seaweedmanagementon thebeach.Theseguidelineshaveoriginated throughpracticeandexperience and are generally consistent with sound practice. However, given thesignificantinfluxofseaweedthatcanoccurduringtheSpringmonths,theCityseekstomaximize thebenefits to thedune systemby improving its seaweedandbeachmaintenancepractices.2.3.1GoalThegoaloftheCity’sseaweedmanagementprogramistolimitdamagetothebeachdunesystemfromrakingactivitiesandpromotetheformationofacontinuousdunesystemalongtheCity’sdevelopedbeachfront. Thepresenceofseaweedalongthebeachisnotdetrimentaltotheconditionoftheshorelineitselfbutcanbeanuisance

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to beach visitors. In general, the City will seek to limit seaweed raking andmechanicalbeachmanipulationtocircumstancesclearlywarrantingtherelocationofseaweed.HarvestingtheSargassum/otherseaweedsforplacementofcoppicesanddunesisabeneficial and valuable practice. Sargassum relocation from the beach, however,shouldconformtotheCity’smanagementandschedulingrequirements.

2.3.2MethodsforSargassumRelocation

WhenrelocatingSargassumfromabovethehigh‐tide line,careshouldbetakentoseparatetheseaweedfromthesandsubstrate,i.e.,withhayrakes(tineequipped)orsand siftingmachinery rather thanwith bulldozer blades.Doing sowill allow thesurfacesand,depositedtherebythesurf, tokeepinserviceasasupplysourceforboth thedunes, bywind‐driven sand, and fornearshorebermsand terraces.Thisdynamicofexchangebackandforthbetweenthebeachandthenearshoreservestomaintain a proper sand budget for both tiers. Removing sand along with theSargassum and even more so with hauling beach sand to supplement duneelevation, subtracts somesupply from theequation.Whilewinddoesmovebeachsandlandwardregularly,relocationofsandunauthorizedbytheCoastalResourcesManagershouldbeprohibited.

2.3.3Location&TimingofSeaweedRelocation.TheCityseekstolimitthelocationandtimingofitsseaweedmanagementpracticesto those areas thatwarrant seaweed relocationmechanically and to the seasonaldemandofthebeach.WithintheCityLimitsallareasarehighlyusedbythepublicsince all beach areas are in front of condominiums and hotels. Areas that have ahigherdemandaregenerallymoreappropriate forseaweedrelocationthanrarelyusedstretchesoftheshoreline.Weatherforecastsandtidesarealwaysconsideredwhendeterminingthewhethertorelocateseaweedortowait.

2.3.4SeaweedCoverage.The City seeks to limit seaweed relocation to circumstances where seaweedcoverageanddepositioninterferewiththepublic’suseandenjoymentofthebeach.ThissubjectivedecisionisamatterofjudgmentandcanbeexercisedbytheMayor,Citymanager,PublicWorksDirector,ortheCoastalResourcesManager.2.4ManagementofrelocatedSeaweed.Inthecourseoftheyear,theCityrelocatesthousandsofcubicyardsofseaweedonthe beach. This volume constitutes a significant resource, as it is excellent dunebuildingmaterial.TheCity’sintentistomaximizethebenefitsthatcanbeobtained

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byeffectivelyusingtherakedseaweedtorebuildtodunes,fillingaps,andraisetheelevationofportionsofthebackbeachthatleadtowashoutsandinundation.Theseareas are typically vegetated through the dune volunteer program to encourageseawardmigrationofthevegetationline.TheCityiscontinuallyadaptingitsbeachmaintenancepracticestousethemostuptodateinformationavailable.

Photo1‐TypicalSeaweedManagementshowingdepositionofseaweedonupperbeach(PhotographbyNancyMarsden,March10,2007)

Photo 1b‐ Same section of beach from above showing the results of the City’sseaweedmanagement and volunteer plantings programs. (Photograph byRichardStockton,May2012)

3.0EXISTINGSHORELINECONDITIONS

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The purpose of this section is to generally describe the shoreline conditions thatexist within the jurisdiction of the City of South Padre Island. In general, theassessment is divided into three broad subject areas: (§3.1) theBeach andBeachProfile,(§3.2)theDuneSystem,and(§3.3)BeachAccessways.

3.1BeachandBeachProfile

TheGulfofMexicoshorelineisacontinuous,sandybeach/dunesystemwithintheCityandextendingtothesouthandnorthoftheCity.Tothesouth,about1mileofbeach separates the City portion of the beach from the north jetty of the BrazosSantiagoPass,adeep‐draftfederalnavigationchannel.Tothenorth,oversixmilesofundevelopedbeach,mostofwhichiswithintheCity’sextraterritorialjurisdiction(ETJ),separatesthenortherlyCitylimitfromthesoutherlylimitofthePadreIslandNationalSeashore.

About 5.5 miles of sandy beaches lie between the southerly and northerly Citylimits, including about 0.75mileswithinAndyBowieCounty Parknear the northend of City. Virtually all of the property immediately landward of the beach isdevelopedwiththeexceptionofthecountypark.

Construction of thenavigation jetties at Brazos Santiago Pass in 1935 has causedprofoundchanges to thebeach/dunesystem in theCity.The jettiesaswell as thedeep‐draft channel act as barriers to both northward and southward longshoretransportofsandalongthebeachandinthesubmergednearshore.

Overthelongterm(yearstodecades),moresandtravelstowardthenorththantothesouthatthispointalongtheGulfshoreline.Asaresult,constructionofthejettiescausedsandtoaccumulateonthesouthsideofthesouth jetty,whilethebeachtothenorthofthenorthjettywasstarved.Initially,thisresultedinarapidretreatoftheGulfshorelineinthesoutherlypartoftheCity.Citybeachesarealsoadjustingtoongoingsealevelrisebymigratinglandwardandupwardoverthelongterm.

After significant initial shorelineretreatduringaperiodofadjustment to thenewconditionswiththejettiesandchannel,thebeachtothenorthofthejettiesbecameshelteredsuchthatsandarrivingfromthenorthnowbecomestrappedinthejetty’sshadow.ShorelineretreatinthesoutherlyendoftheCityhaseffectivelyceasedandseawardadvancehasnowbeendocumented.ThenortherlyportionoftheCitystillexperiences shoreline retreat, with a more or less stable shoreline segment inbetween(seeFigure1).

City streets and individual property lines were laid out decades ago, such thatchangesinthebeachlocationduetoshorelineadvanceandretreathaveaffectedthedepth of the beach/dune complex between theGulf ofMexico and the beachfrontdevelopment.

It is apparentwhen viewing thepresent shoreline location relative to streets anddevelopedpropertiesthattheshorelinehasrotatedinacounterclockwisedirectionaboutapointroughlythreemilesnorthofBrazosSantiagoPass.Cross‐shorebeach

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surfaceprofilesextendingfromthedunesoutintodeepwaterandtakenatintervalsalongthebeachappeartobeverysimilarfromthesouthendoftheCitytothenorthend,eventhoughtheprofilesaremigratingseaward(southend)orlandward(northend) over time such that the effects of development on the landward ends of theprofilesarequitedifferent.

3.1.1Shorelinechangerates

The State of Texas has designated the University of Texas—Bureau of EconomicGeology(BEG)astheofficialrepositoryofstatewideshorelinechangeinformation.BEGmappedhistorical shorelinesusingdatabeginningwith charts from themid‐19th Century, to 20th‐Century aerial photography, to 21st Century Lidar. Longtermaverageannualratesofshorelinechangeweredeterminedbasedoncomparisonsofthese historical shorelines. The determinations generally do not consider thephysical processes causing shoreline change; rather, they are only indications ofpastratesofsuchchange.

Along theTexas coast, there is considerable variability in actual shoreline changerates from year to year. A typical cycle consists of a large storm‐induced retreatfollowedbymonthsandsometimesyearsofrecoveryduringrelativelybenignwaveconditions. Shoreline locations also vary seasonally, typically exhibiting winterretreatandsummeradvance.

ForpurposesofthisErosionResponsePlan,thebeacheswithintheCityaredividedintothreezonesbasedonBEGanalyses(seeFigure1):

(1) The Southerly Zone of Accretion (green) ‐‐ average annual shorelineadvanceinexcessof+2ft,ashorelinereachroughly12,000feetinlength;

(2)TheCentralZoneofStability(yellow)‐‐averageannualshorelinechangeof‐2ftto+2ft,ashorelinereachroughly4,000feetinlength;and

(3)TheNortherlyZoneofErosion(red)‐‐averageannualretreatofgreaterthan‐2ft,ashorelinereachroughly11,000feetinlength.

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Figure1:SPIaccreting,Stable,andErodingZones

3.1.2Annualvolumelossesandgains

Dataregardingthemagnitudeofsanddeficitsandsurplusesat locationsalongtheCitybeachfrontisusefultoinformanydiscussionofreasonablealternativeactionstoaddressshorelineretreatandreduce futurepublicexpendituresdue toerosionand storms. The BEG shoreline change rates provide an excellent basis for aplanning‐levelestimateofthevolume(quantity)ofsandneededtooffsetsomeorallofthesanddeficitwithintheCity,(includingtheeffectofsealevelrise)thatresultsinshorelineretreat.

Knowledge of volume requirements leads directly to cost estimates of sandmanagement strategies.Once these strategies canbe viewed indollar terms, theycan be compared to the costs of dissimilar alternative strategies such as landpurchasesorconstraintsplacedupondevelopmentorpost‐disasterreconstruction.

TotheextentthattheERPisbydefinitionintendedtoaddresstheeffectsoferosion,thesoutherlyaccretingbeachisnotanobviousfocalpointofplanningefforts.DuneresilienceandpublicaccessissuesintheaccretingareaareaddressedelsewhereintheERP.However,itisimportanttounderstandtheextentofsandaccretioninthisarea as a potential resource for combating sand deficits and shoreline retreat in

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areas further to the north while acknowledging potential equity issues that mayarisedependingontheresponseapproachbeingconsidered.

Thenotionofanannualvolumechange isuseful forplanningandcostestimating,buttoreiteratethediscussionofshorelinechangerates,themechanismofchangeisgenerally not a steady gain or loss of sand. Rather, episodes of large changes areseparatedbypotentially longperiodsofrecoverytoequilibrium.Thatequilibriummay be (and generally is) a gradual gain or loss over the long term. Thesemechanismsshouldbekeptinmindduringthedevelopmentofresponsemeasures.

Planning‐level estimates of average annual volume changewere developed usingtypical beach profiles taken in the accreting (south), stable (central), and eroding(north) zones of the City beachfront and translating them landward or seaward.This simple estimation approach is appropriate in the context of the ERP level ofeffortandisnottheresultofanoriginal,rigorousanalysisofcoastalprocesses.Foreaseofcomparison,quantitiesarebrokendowntocubicyardsofsandper footofbeach (cy/ft) throughout theERP.Thisunit canbemultipliedbyaselecteddollaramountpercubicyard($/cy)toarriveatacostperfootofalongshorebeachlength($/ft).

Intheaccretingzone,whereaverageannualshorelineadvancerangesfrom2fttoabout10ft,theaverageannualincreaseinsandvolumerangesfrom2cy/ftto11cy/ft.

Thestablezone,bydefinition,doesnothaveanaverageannualaccretionorerosionquantity.

Intheerodingzone,whereaverageannualshorelineretreatrangesfrom‐2ftto about ‐5 ft (within theCity limits), the average annual decrease in sandvolumerangesfrom2cy/ftto5cy/ft.

NotethattheeffectsofsealevelrisearecapturedwithintheBEGratesanddonotneedtobeaddedtothecalculationsbasedontheBEGrates.

In the three figures below (designated 2a, 2b and 2c), typical areas are shown ineachofthethreebeachsections–accreting,stableanderoding.

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InFigure2a,itisapparentthatsufficientbeachdepthexistsforadunesystemanddune elevations can reach +14 feet or greater. Beach conditions in the accreting

Figure2a

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area are thus conducive to dune restoration, enhancement and replanting.

Figure 2b depicts a typical section of the beach/dune system in the stable area.Here, dunes are typically narrower than those found further south and dune

Figure2b

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elevationsareusuallylower.Thelackofdunewalkoversresultsintheproliferationoffootpathsthroughthedunesandfragmentationofthesystem.

Figure2c

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Figure 2c depicts a typical section of the beach/dune system in the eroding area.Here, dunes are extremely narrower than those found further south.

3.1.3AreasofConcern

Itcomesasnosurpriselocallythattheareaofgreatestgeneralconcernisthenortherlyzoneofretreatingshorelines,asdepictedinFigure2c,above.Progressingnorthwardfromthejetties,thebeachgenerallynarrowsandissubjectedtoincreasinglyhighererosionrates.AtthenorthernCitylimit,inthevicinityofAndyBowiePark,thenarrowbeachesleaveslimitedareafortheformationofdunesand,wheredunesarefound,theyaretypicallylower,morefragmented,andprovidelessprotectiontothedunesfoundinthesouthernreachoftheCity’sbeach.

Asdescribedpreviously,theshorelineisrotatinginacounterclockwisedirection,whilethehistoricalbuildinglineandtheexistingbeachfrontbuildingswithintheCityremainstationary.Othermorelocalizedareasofconcernareportionsofthebeachweredunesdonotexistatthelandwardsideofthedrybeach,asshowninPhoto2below.

Photo2‐DunesarelimitedorpoorlyformedinerodingareasalongthenorthernreachoftheCity’sbeach.(PhotographbyRichardStockton,May2012)

Thesenarrowbeachareasaremoresusceptible todowncutting(verticalerosion),causingsandlosseitherseawardintodeeperwaterorlandwardintothedevelopedareaandlosttothebeach/dunesystem.Thisisbecausetheduneprovidesabarrierto landward washover as well as a reservoir of sand that is drawn down to thebeach during elevated tides and high wave action. Without this barrier andreservoir,muchmoresandlosscanoccur.

Washoversdooccurperiodically,andresultinthetransportofsignificantquantitiesofsand into theLagunaMadreandseaward intodeepwater.Thesequantitiesareeffectivelylosttothebeach/dunesystem,althoughsandwashedintotheLagunaisanaturalpartofthebarrier island’sresponsetorisingsealevelastheislandmoveslandwardandupward.

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Natural washovers tend to reappear in similar locations over time. In addition,development patterns can create manmade washover opportunities. A shore‐perpendicular street end not adequately protected by a dune is an example of awashoveropportunity.

In termsof otherbeach responses to stormactivity, any structural feature that isimpactedbywaveactionhasaneffectonthebeachprofileatthatlocationanduponadjacentareas.Anyexposedfeaturesuchasaseawall,dunewalkover,orpavementwill have an effect. Mitigation opportunities to addresswashovers and structuralimpactsarediscussedelsewhereinthisreport.

Althoughdunesanddunemaintenance/mitigationarealsodiscussedelsewhereinthisreport,itisworthnotingthatdunescannotbereadilysustainedatalocationonthe beach that is too low to provide for a roughly 200 ft depth of sandy beachbetweenthetypicalwaterlineandtheforedune(seeFigure2c,Photo3,andPhoto3b).

Photo3‐NarrowbeachatWhitesandsSt.,dunerestorationwouldbeproblematicseawardofthestructure(PhotographbyNancyMarsden,March10,2007)

Photo3b‐NarrowbeachatWhitesandsSt.(PhotographbyRichardStockton,May2012)

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Thatistosay,innortherlyareasoranyareawherethewetbeachistypicallywithinroughly200 ft of thehistorical building line, beachnourishmentof thedrybeachand submerged nearshore is appropriate before or in conjunction with dunebuildingefforts.Otherwise,restoredduneswilltendtobeshort‐livedandonlyserveto nourish the beach with sand while losing the value of any dunemitigation/planting/wateringefforts.

3.1.3.1Hotspots

TheBEGshorelinechangedataportraysafairlyconsistentprogressionofchangingrates fromsouthtonorthalongtheCitybeachfront.Oneexampleofarelativehotspot can be seen near the northerly City limit. This localized increase in the BEGretreat rate is likelyanartifactof the locationbeingahistoricalnaturalwashoverarea,althoughfillassociatedwiththedevelopmentofthisportionofthebeachfronthasrestoredelevationssuchthatthewashoverwillnotbeeasilyactivated.

3.1.3.2Developedandundevelopedbeachfronttracts

ThevastmajorityofbeachfrontpropertieswithintheCityaredeveloped,includingbulkheadsalongthehistoricalbuildingline.Fromanerosionresponseperspective,there is little to suggest at this point that infill development of the remainingundevelopedparcelswillbedetrimentaltoCity‐wideerosionresponse.

Protectionofthebuiltenvironmentlandwardofthebeachfromdamagecausedbycoastal storms is dependent upon themaintenance of a healthy, continuous dunesystemwhichisitselfpredicatedonadrybeachofsomedepthbetweenthetypicalwaterlineandthedunes.

Anecdotalevidencesuggeststhatongoingdunebuilding/restorationactivitieshaveresulted in some seaward advance of the beach itself. Such a result is notinconsistentwiththecoastalprocessesatworkinSPItotheextentthattherestoreddunes are contributing sand to the beach over time. However, within the limitedscope and level of effort facilitated by the production of this ERP, there isinsufficient evidence to make a strong determination of either correlation orcausationofthiseffect.

3.1.3.3Vulnerability

The City, including its public infrastructure and private property, is vulnerable totheeffectsofbeacherosioninseveralways,includingthefollowing:

Discrete events (storms)—High tides and waves can directly impact andcause damage to infrastructure and property that is not adequatelyseparatedfromGulfwatersbyacontinuousandrobustbeach/dunesystem.

Washover—Internal flooding within the City can occur as a result ofactivation of natural or manmade washover locations allowing high Gulfwaterlevelstoencroachlandwardofthedunesystem.

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Sand deficit—Assuming a static building line, sand deficit causes thelandward retreat of the beach/dune system over time. Eventually thestationarystructuresimpacttheretreatingdunesandbeach,weakeningtheCity’s defense against coastal storms and increasing the frequency andseverityofdamage.

Relative sea level rise—The natural response of a barrier island toprogressivesealevelriseisfortheislandto“rollover”aswashoverdepositsraise elevations in thebackbay.Thisprocess is ongoing in SPIdespite thepresenceofdevelopment.

Effects of built environment—The built environment primarily affects theavailability of sand to the beach/dune system. The navigation channel andjetties starve the entire City of beach sand, while beachfront developmentboth captures sand beneath pavement and causes more wind‐transportedsandtobelosttolandwardareas.

Vehicle/pedestrian impacts—Publicvehiclesandpedestrianscausedamagetodunevegetation and the loss of dune elevation.The resultingweakeneddunesystemismoresusceptibletowaveerosionandwashover.

3.2. DuneComplexandUplands

Thefollowingdescriptionsarebasedon2011observationsanddata,whichfollowaperiodofrelativequiet, in termsof theabsenceofseverestormsandwaveactionalongSouthPadreIsland’sGulfshores.i.e.,withoutseriousbeach/duneerosionandloss.

3.2.1Location,Elevation,andDepthofDunes.

Dunesare found inbothhealthyanddegradedstates in theCity’s jurisdiction, thebetterdunesbeingcomponentsorpartsofcontinuousdunefieldsorsystems.Inthesouth, certain areas are devoid of dunes, having been removed over time byrecreationaluse,beachaccess,andstormsurge.(seePhoto4below).

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Photo4‐Typicalareawhereduneshavebeendamagedbyrecreationaluseandbeachaccess(showingFrankePlaza,Radisson&“CocaColaBeach(PhotobyNancyMarsden,March2007)

Inthebeach’scentralsection,dunesarefairlycontinuous,withdisruptionsforthecausessimilartothesouthbeachexamplesbutofgenerallysmallermagnitudes.Inthenorth,particularlyintheCity’sETJ,withsparserdevelopmenttodate,dunesaregenerallybroaderandhigher,arecomponentsofintegratednaturaldunefields,andhaveexperiencedfewerdisturbancesotherthannaturaldunemigrationandwind‐erosiondynamics.

Photo5 ‐Areaofgenerally continuousduneswith intermittent footpathdamage (PhotobyRichardStockton,May2012)

Dune Elevation: At the south end, most dunes are on average below 7 feet inelevationabovegrade,withmanybelow5feet. Inthecenter,stableandvegetated

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dunes range in elevation, on average, between 6 and 11 feet above grade. In thenorth, theaverage ishigher,withsomestableandvegetateddunesreaching12to16 feet in elevation or higher. In the developed areas of the beach, as previouslynoted,manyduneshavebeendisturbed,eroded,and/orremoved.

DuneDepth: Inthemoreextensivelydisturbedareas,someduneformationshavedisappearedentirely,whileremnantdunes,mainlylowinelevation,varyfrom20to40 feet in depth (running landward from the shore), in many examples. In theslightlydisturbedreaches,somelargelyintactduneclustersextend50tomorethan100feetindepth,withfairlydistinctforedunes,interduneareas,andbackdunes.Intheleastdisturbedareas,primarilyinthenorthofAndyBowiePark, includingtheETJ,dunefieldsarefoundinexcessof200feetindepth.Wherehousingandotherdevelopment has not yet occurred along Gulf Boulevard in the north,many dunefields extend the full distancebetweenhighbeachand the road, inmany cases inexcessof300feet.

Analysisof2010surveydatarevealsthatasignificantpercentageofthe landwardbeachareawithintheCitylimits‐‐thezoneofpotentialfordunedevelopment‐‐isactually covered by established and emerging dunes. The City would gain inprotectionfromstormdamageprotectionwerethispercentagetoincrease.

Figure3abelowshowsbeachelevationsaboveandbelow+8feet,withareasshadedgold being greater than +8 ft. In this figure, it is typical that beach and duneelevationsreachat leasteightfeet,butareasof lowerelevation,usuallycoincidingwithfootpaths,accessroads,orduneareasclearedtoexpandthedrybeach,canbeseen.

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3.2.2.DuneVegetativeCover.

Whereduneshavebeenprotected,bothbydunefencingsettoaugmentthedunesby sand trapping and by owner and visitor adherence to City and non‐profitorganizationalguidanceonduneprotectionandsustainability,duneplantsarewellestablished (see Photo 5 above). The City, with extensive help from visitors, andnon‐profits through theDunePlantingeffortshas establishedaplantingprogram.Through the program these plants have naturalized onto the dune surfaces,resultinginsuccessfulcoverandabuild‐upofdunedefensesagainststormeffects.

Furtheranalysisofthe2010aerialphotosrevealsthatmostoftheestablishedandemerging dunes within the City limits are well vegetated, where the dunes areallowedtoexist.Totheextentthatfurthervegetatedcoverisplantedandsupportedand dunes are restored and expanded in the bare areas, properties andinfrastructure landward of these zones can be made more secure from stormdamage.

3.2.3DuneHotspotsandOverwashAreas.

TheCity’sdunesystemisfragmentedandinconsistentlimitingtheprotectivevalueofthisnaturalstormandfloodbarrier.Thereareseveralcausesforthiscondition,whichcanbecataloguedasfollows:Excessive number pedestrian trails andwalkways through the dunes– Along theCity’s4mile‐longbeachfront, therearedozensofunimprovedpedestrian trailsorpaths through thedunes. Cumulatively, thesepaths result in a substantial lossofdunemassfromdowncuttingduetofoottraffic.

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Photo 6 ‐ Typical footpaths causing dune fragmentation. Opportunities for consolidatingthesepathsshouldbeexplored(PhotobyRichardStockton,May2012).

In addition, no effort has beenmade to consolidate or limit the number of dunewalkovers along the developed shoreline. While dune walkovers are clearlypreferable to unimproved pedestrian trails or paths, the dune system could bestrengthenedifpublicandprivatewalkoverswereconsolidatedwhereappropriate.PoorDuneWalkoverDesign‐Thelowprofileofsomedunewalkovershinderssandaccumulation and dune growth, primarily on the lee of the walkovers. Poorwalkoverdesignalsocurtailsdunebuildingoverallbypreventingsandblow frommovingandaccumulatingbeneaththelowspans.Intentional dune excavation and relocation of dune sand – In previous decades,significant portions of the City’s dune system were intentionally removed in anefforttocreateorexpandrecreationalareasonthebeach,improveoceanviews,andexpandpedestrian trails andpaths.While thispracticehas ceased in theCityandeffortsareunderwaytorestoreandenhancethedunesystem, the impactof theseactivities is still visible today. Based on thedata available, it is roughly estimatedthat 144,000 cubic yards of imported sand would be needed to construct acontinuousdunealongthecity‐frontwitha10‐footelevationandaminimumbasedepthof60feet: Southernzoneofaccretion 89,550cu.yds. Centralzoneofstability 15,740cu.yds. Northernzoneoferosion 39,000cu.yds.

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OverwashAreas‐Thelocationsinwhichstormandspringhightideoverwashoccuraregovernedbyacomplexsetofcoastalprocessesanddynamics.Humanimpactsalso help determinewhere overwashmayoccur, as in the instances of street‐endbeach access improvements where dune crossovers are built to insufficientelevations.Insuchcasesthelowprofilesofthecrossoversandwalkwayextensions,combinedwith theabsenceofhighandmoderate‐heightvegetateddunes in theselocations contribute to the funneling of surging waves and wind through these“windowsofopportunities”andintothestreets.OverwashalsooccursinundevelopedorsparselydevelopedareasoftheCityatthenorth end. Here, too, causative factors are complex, but wind and wave forcesgenerallyactfreelywheredunesareabsent,whateverthecauseandwherethehighbeachhasbeenloweredbyeitherwinderosionorhumanactivityorboth.Here,inthenorth,naturalforcesdominate,whileinthesouthernandcentralreachesoftheCity’s shoreline, human intervention can contribute to the sharpening of naturalstormimpacts.

3.2.4Conclusion

InthecaseofSouthPadreIsland,thebestapproachtoreducepublicexpendituresand property damage due to erosion and storms is to undertake a program tonourishthebeachandenhanceandrestorethedunesystemthatformsthefirsttierofprotectionforuplanddevelopmentandinfrastructure.

3.3.BeachAccessHandbook(AvailableontheCitywebsite)

TheCityinventoriesanddocumentsallbeachaccessconditionsonanannualbasisto show improvements and track conditions of existing walkovers or mobi‐matsthat may be in need to repair. Information available in the document includes:photos, amenities, disabled accessibility, construction year and costs, and fundingsources. This document is used to plan for budget and grant needs. Because thedocumentisupdatedonanannualbasisthemostrecentversioncanbeaccessedontheCityofSouthPadreIsland’swebsite.

Photo7–AnexampleofinformationavailableintheBeachAccessHandbook

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4.0 DESIREDSHORELINECONDITIONS

4.1BeachandBeachProfile

Inthedesiredcondition,thereisadequatespacebetweentheGulfofMexicoandthedevelopedbeachfronttomaintainanaturalbeachdepthandhealthyprotectivedunesystem.

ThebeachalongthesouthendofSouthPadreIslandiscontinuous,healthy,andunhamperedbystructuralencroachmentsduringtimesofnormalwaterlevels.ItisonlytotheextentthatinsufficientspaceremainsbetweenthebeachandexistingbeachfrontdevelopmentthatactiveinterventionsuchasbeachnourishmentisneededtosustaintheCity’sdesiredbufferzone.SuchisthecaseonlyinthenortherlyerosionzonewithintheCity.

Theprofileor“shape”ofthebeach—includingitsslope,thenumber,sizeandlocationofsandbarsinshallowwater,beachdepthbetweenwater’sedgeandthedunes—isdeterminedbythewaterlevelsandwaveconditionspresentoverlongperiods,asoccasionallyinterruptedandchangedbystorms.Assuch,itisdifficultandexpensive,ifnotaltogetherfutile,toattempttocreatealastingbeachprofilethatdiffersfromthe“natural”profile.

Theremustbeaclearunderstandingamongdecisionmakersandthecommunitythatinordertoprovidespaceforahealthydunesysteminthenortherlyerosionzone,theentirebeachprofileincludingthesubmergedpartmustbe“moved”seawardbyprovidingtheappropriatequantityofsand.Inpractice,theaddedsandcanbeplacedonthevisiblebeach,butitmustberecognizedthattheGulfwillreworkthematerialovertheentireprofileincludingtheoffshoreareato15ftormoreofdepth.Thus,whendiscussingthelong‐termapproachtomaintainingahealthybeach‐dunebuffer,wearetalkingabouteverythingbetween15ftdepthandthehistoricalbuildingline.

4.1.1Beachdepthandelevation

ThetypicalbeachdepthinSPIbetweenatypicalwaterlevel(sayMeanSeaLevel)andthevegetatedforeduneisabout200ft.Theactualdepthcanvaryseasonallyandinresponsetostorms,butforplanningpurposesthistypicaldepthisuseful.

Theelevationatwhichforedunesemergeandtendtosustainvegetationisaminimumofabout5ftabovethetypicalsealevelinSPI.Thatis,thebeachelevationvariesfromsealeveltoabout5ftwithintheroughly200ftdepth.

4.1.2Sandvolumeandsources

Twogoalsmustbeachievedtoprotectandmaintaindevelopmentalongthehistoricalbuildinglinewithoutretreatandwithahealthybeach‐dunebuffer.First,sufficientroommustbeprovidedbetweenthewater’sedgeandthebuildinglinebymovingthebeachprofileseawardtocreateastablebeachdepthandhealthydune

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system.Second,oncethebeachandduneareestablishedatthedesiredlocation,theannualsanddeficitmustbebroughttozerothereafter.

Planning‐levelestimatesofsandquantitiesneededtocreateandmaintainarelativelystableshorelinelocationweredeterminedbyaccountingfortheamountneededtomovetheentirebeachprofile(between15ftdepthandtheforedune)seaward.

InroundnumbersforthespecificcaseofSPI(notapplicabletoallbeaches),each1ftofprofilemovementrepresentsavolumeofapproximately1cy/ftofbeach.Basedonthisapproximation,thesandrequiredtomovetheprofileofthenortherlyerodingzone(11,000linearfeetofbeach)isroughly660,000cubicyards.Thisassumesthepresentbeachdepthisacceptablebutspaceforanadditional60ftofduneisneeded.

Anadditionalsandcontributionwillthenbenecessarytooffsettheaverageannualshorelineretreat,whichwillcontinuetooccur.Theapproximateamountneededtomaintainthenewshorelinelocationinthenortherlyzone,andincludingasmallamounttomaintainthecentral“stable”zoneasdefined,is40,000cubicyardsperyear(cy/yr).Thisfigureisbasedonanannualretreatrateof0ftto2ftinthe“stable”area,andretreatvaryingfrom2to5ftinthenortherlyerodingzone,multipliedbythebeachlength(say2,000ftofstablebeachand11,000ftoferodingbeach)andtheprofilemovementfigureof1cyperftofbeachperftofretreat.

PotentialsandsourcesincludethefederalnavigationchannelatBrazosSantiagoPass,accretionslocatedimmediatelysouthandnorthofthepassjetties,offshoreborrowsites,thestatehighwayrightofway(perhistoricalpractice),maintenancedredgingmaterialfromtheGulfIntracoastalWaterway(GIWW),andland‐basedsources(includingbarge‐accessibledepositslocatedneartheGIWWmanymilesnorthoftheCity.

Conservationcanalsobeviewedasa“source.”Examplesincludereducinglossesofwindblownsandintodevelopedareas,lossesofwaterbornesandthroughwashovers,avoidanceofpavementoversandthatiswithintheactivebeach/dunesystem,andtherecyclingandcrushingofglassintosand‐sizegrains.

4.1.3Methods

Dredgingofsandfromsubmergedsourceswilllikelycontinuetobethemostcost‐effectivemethodofproducingrequiredvolumesofsand.Thebeneficialuseofmaterialdredgedfromthefederalnavigationchannelsisparticularlycosteffective.

Healthydunesrepresentperhapsthebesttrappingmechanismtolimitthelandwardlossofbeachsandfromtheactivebeach/dunesystem.Sandfencingcanboostthetrappingofwindblownsandaswell.

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Apre‐positionedcontractwithCorpsofEngineersshouldbeexploredforemergencydredgingeventsthattendtobeassociatedwithsignificantcoastalstorms,toensurethatvaluablesandisnotsimplydumpedoffshoreindeepwater.

4.1.4Estimatedannualcost

Thehistoricalcost(totheCity)forthereceiptofmaterialdredgedfromthefederalnavigationchannelhasaveragedabout$1/cy.Theactualcosttopayforsimilardredgingnotassociatedwithchannelmaintenance,asmaybethecaseforalarge,stand‐alonebeachnourishment,isestimatedtobeabout$6to$8/cybasedonrecentnavigationdredgingcosts.ArecentexampleofsandimportedintotheCityfromamainlandsourcewaspricedat$10/cywhichshouldperhapsbeinflatedtobetween$10and$12/cygivencurrentfuelcosts.

Thus,aplanningestimateforalargeinitialnourishmenttomovetheprofileseawardtoprovideroomforahealthydunesystemintheerodingzonecoulduse$10/cyasaconservativeestimate.Thisunitcostmultipliedby660,000cysuggestsa$6.6millionsandcosttowhichplanning,engineeringandpermittingcostscanbeadded.

Similarly,theannualmaintenancevolumeof40,000cycanbemultipliedby$10/cytoarriveata$400,000annualsandcostforplanningpurposes.

4.2DuneComplex

In general terms, a strong and stable dune system, with a capacity for relativelyeffective resistance to minor and moderate storm and tidal events, capable ofsustainingdunevegetation,andprotectioninsomemeasureofbackshorepropertyandinfrastructure,exhibitsthefollowingparameters:

• Relatively high quantities of dune and beach sand, over the beach‐dunecross‐section,foreachlinearfootofbeach‐line

• Dune landforms that conform to mature dune types, that is, classicallystableshapesthatareprimarilywind‐carved,withwind‐deliveredaccretingsandbalancing,byandlarge,wind‐drivensandloss

• Absenceofhuman(footandvehicle)disturbanceinthedunesandonthebeachsurfacesfrontingtheforedunes

• Minimumprimarydune and inter‐dune elevationsof 10 feet,with somedunesinthesystemreachinganoptimum12feetinelevationorgreater

•Vegetationwithminimumeighty‐fivepercentcoverage,orbetter,ofdunesurfaces

AlthoughprotectionofSouthPadreIsland’sbeachanddunesfromerosion,acentralsubjectofthisplan,isvitaltodefenseoftheurbanfabricandthelivesofitscitizens,protectionofnaturalhabitatisalsoamatterofhighestpriority.Itisaswellamatter

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of interest to thousands of beachgoers, citizen and visitor alike, andprotection ofnaturalhabitatisanobligationoftheCityofSouthPadreIsland.

Securingamplebeachdepthandwell‐vegetatedhighanddeepdunesareessentialtobeachwildlifeastheyareforerosionprotection.AsstatedontheCity’sWebsite,habitat restoration (andmaintenance in a quality state) is a public priority: “. . .numerous species suchas theKempRidley sea turtlesandPipingPlovers relyonwide,healthybeachesasaplace to live, feedandnest.”Asdovarious terns,gulls,sanderlings, willets, crabs, and other life forms that help make up the completeshoreecosystem–andserveaskeyvisitorattractions.

TheCity’sWebsiteconciselypointsoutthat“Dunesareimportantbecausetheyareour first line of defense from storms and flooding. Coastal communities areprotected from the storms that occur in the Gulf by a system of vegetated sanddunes which provide a protective barrier. The General Land Office has directedcoastal communities to protect these dunes becausestabilized, vegetated dunesofferthebestnaturaldefenseagainstdamagecausedbystorms.”

4.2.1GoalsandObjectivesofaSPIDuneEnhancementProgram

The goal and objectives of restoring and enhancing dune vegetative cover aredefinedabove.Locally,theCityisworkingwiththeShorelineTaskForcetodevelopa dune enhancement technique first effectively demonstrated by Padre GrandeCondominiumsandsecondbyLaConchaCondominiums.TheGLOapprovedthesetwo pilot projects before the beach and dune plant amendment was approved.FollowingthepilotprojectssuccesstheCity’sbeachandduneplanwasamendedtoallowforsuchprojectstotakeplace.Ingeneral,thetechniqueisintendedtoworkinareaswhereduneshavebeenlostoronlyremnantsremainorwhereexcessivesandhas built up in excess of +10 feet elevation. The technique also seeks to makeeffectiveuseofrakedseaweedtoadvancethedunesystemfromitsmostlandwardpositionseawardtotheextentofthenaturallineofvegetation. Usingsandfenceand rakedseaweed,piles areplacedon the seawardedgeof remnantdunesor indunegaps.Vegetationisencouragedbyirrigationandallowedtopropagate.Asthevegetationlineadvances,relocatedseaweedpilesareaddedtothetoeofthedune,shapedto10 ftelevation,and irrigated. Over time,dunevegetationhasadvancedseaward to the position itwill naturally occur, such that no encroachment of thepubliceasementoccurs.Inareaswereduneelevationsexceedaspecifiedelevation in theBeachandDunePlan,dunescanbe“topped”andthesandusedfirsttoadddepthandsandvolumetotheimmediatesurroundingdunefieldintheareasoflowelevationbringtheareatoa10’ elevationwhichwill strengthen thedune systemagainstblowouts. Secondlythesandcanbetransportedtoareaswithweakdunestoelevateandstrengthenthedune systemagainst overwash and inundation. Theseprojects require individualbeach dune permits and should be undertaken sparingly and preferably only inareasthatarestable.

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Location: The goal of an erosion‐control and protective dune program is to bothpreserve mature, high, vegetated dunes, and to restore and revegetate disturbedandmissingdunes, yielding fully vegetateddune fieldswithample elevations anddepthsbetweenthehigh‐beachandthebuildingsetbackline(SBL).Objectivesthatwillneedtobemetinthisregardaredunepreservation,repairandrevegetationofdisturbed andmissing dunes, infilling of disturbed and dune‐depleted areaswithnewdunesandplantings,installationofdune‐fencingandotherdunedevelopmentand maintenance measures, consolidation of walkways wherever feasible,development of new walkways and dune crossovers that achieve sustainablebeachgoer access and are of superior design and durable construction, andelimination of beach access ways that are detrimental to the dune system. Theforegoingrecommendationforconsolidation isconsistentwiththe2007DuneGapReport, which recommended that the City, “consolidate paths, when possible,throughthedunesforlessimpact.“Elevation: Dune building and rehabilitation should meet the goal of providingsufficient elevation in the dune fields to enable the dune system to function as aprotective feature in moderate storm conditions. By defending beachfront andupland buildings, infrastructure, and lives from severe storms. Where sufficientbeachdepthexists,theCity’sobjectiveistoprovideacontinuousdunesystemwitha minimum elevation of +10 feet in areas where visibility of the surf zone is animportant consideration, anda targetoptimumelevationof+12 feetorhigher, asdeterminedasappropriatebytheSPICoastalResourceManager,wherevisibilityofthesurfzoneisasecondaryconsideration.Depth:Beachdynamicswillneedtobetaken intoaccount,withdeeperbeachanddune fieldsmore achievable in the southern (accreting beach) reaches, narrowerbeach and dune fields probable in the northern (depleting) reach, and mixedconditionsinthecenter.TheCityintendstodevelopacontinuousdunefield,alongtheentirebeachfront,between thehighbeachand theSBL.Wherebeachdepth issufficient, the base dune depth should be a minimum of 60 feet, with 100 feetpreferable. In thenorthernerodingareas,aminimumbasedunedepthof60 feetshould be attained and efforts to nourish the shoreline should be aggressivelypursuedsuchthatbasedunedepthof100feetcanbesustained.Dune Volume: In order to function as a protective feature in moderate stormconditionsatargetsandvolumeshouldbeused.TheCitywillstriveforeverybeachfrontpropertytohaveaDuneVolume(DV)ataminimum66cyandagoalof110cyperlinearyard.Usingtheabovedesirableduneconditionsata10’(3.3yd)elevationwith100’(33.3yd)ofdepthequalstoatargetvolumetricgoalof110cyperlinearyardofbeach.Wherebeachwidthsdonotallow foradunewitha100’depth theelevationrequirementscanbeadjustedinordertomeetthetargetdunevolume.Methods: In the Figure, below, recommended dune plant species are identified.Sargassumandotherseaweedinthewracklinewillcontinuetobecritical inbothretaining moisture on the wet beach, thereby sustaining its resistance to wind

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erosion,andinprotectingdunes,especiallythefore‐dunes, fromwinderosionandhighsurferosion.Remediation and/or consolidation of footpaths will be critical if the City is toestablishacontinuousdunefieldataminimumelevationof+10feetandbasedepthof60feet.Closecoordinationwithlandownerswillberequired.

Dune Fencing to Control Foot Traffic: Installation of stable dune fencingapproximately2feetawayfromthetoeofslopeononeormoresidesofthehealthydune, as ruled as necessary by the City’s coastal resources manager, should beinstalled to deter foot traffic across dunes. These barriers should be openedsignificantlyor fully removedduring turtlenesting seasons.Thealignmentof thisfencing should be adjusted as necessary as determined by the Coastal ResourcesManager. This protective fencing need not follow guidelines for sand entrapment(dunebuilding)astheperimeteralignmentsareintendedtopreserve(protectfromhumanimpacts)ratherthanbuild.

4.2.2SandVolumeandSources

Sand Volume: The estimated volume of sand needed to restore the dune field is144,000 to 161,540 cubic yards with the Southerly Zone of Accretion requiringapproximately39,000cu.yds,theCentralZoneofStabilityrequiring15,740cu.yds.,

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and the Northerly Zone of Erosion requiring 89,550 cu .yds. up to as much as106,800cu.yds.

SandSources:Sandsourcesfordunebuildingmayinclude:(1)offshoresources;(2)sand dredged from the Brazos Santiago Pass as part of the USACE’s routinemaintenanceofthechannel;(3)windblownsandonandwithintheright‐of‐wayofParkRoad100;and(4)truck‐hauledriversand

4.2.3Methods

Giventhelimitedamountofsandinthesandbudgetutilizingallavailablesourcesisamust.ThroughtheDunePlantingprogramandutilizationofsandfencestheCitycanbuilddunesthatwillprovideprotectiontopublicinfrastructureandstoresandtoreplenishthebeachsystemafterastorm.

ThroughtheDuneRidgeEnhancementprogramsandthatisstoredinsanddunesinelevationsabove+10feetorhighercanbeusedtofill inlowelevationstopreventblowoutsoffrontaldunesandtobuildasolidcontinuousdunesystemwithagoalofbuildingadunesystemtofunctionasaprotectivefeatureinstormevents.

4.2.4EstimatedCosts

Giventhevarietyofpotentialsandsourcesfordunebuilding,nosinglecostestimatefor dune sand can be provided. It is expected however that obtaining sufficientquantities of off‐beach sand (sources other than windblown sand of seaweedmanagement)couldcostatleast$10percubicyardandincreasesignificantlyfromthere.

ThespeciesandtypesofplantsneededforthedunerevegetationeffortsarenotedaboveandfullydescribedintheGLODuneProtectionManual. BasedonavailableinformationplantsarecurrentlyavailabletotheCityat$0.42perplant.

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4.3BeachAccessPoints–PublicAndPrivate

4.3.1AccessEnhancementGoals:

TheCityisdedicatedtoprovidingthepublicaccesstothebeach.WhenpossibletheCitywill fund access improvements through hotel/motel tax but relies heavily ongrantsformatchingfunds.

4.3.2Walkovers,Mobi‐mats

Walkover Design Standards: Both public and private access ways should meetstandardsforupgradedconstructionmethodsanddesigninordertoreducestormdamageandpost‐stormrepaircosts.

Stainless steel cable‐stay railing systems are recommended for access ramps,staircases, and crossovers.Though theyare costlier thanwoodcounterparts, theyare highly resistant to storm damage and salt spray corrosion and require lowermaintenanceandrepairattention.

For ramp, crossover, andotherhardenedwalking surfaces, severalhighlydurablematerials havebeen substituted forwoodplanking in recent years. These includeTREXandotherplasticizedcompositesandboardsmadefromkenaf,aplantgrownandprocessed,amongotherlocations,inWillacyCounty.

As the City proceeds in the design of additional street‐end and other ramps,crossovers,andwalkways/boardwalks,suchalternativematerialsandtheircosts–initialandlife‐span–shouldbeinvestigated.

Withemploymentofsturdierstructuralelementsandmoredurablerailingsystemsandwalkwaysurfaces,O&Mcostsmaybekeptatminimallevelsoveramulti‐decadelife‐span.

ADA‐conformingHandicappedRampsLinking toDuneCrossovers:TheCitybuildshandicappedaccessiblerampsfromstreet‐endsonacontinuingschedule.ByTexasAccessibility Standards and Americans with Disabilities Act criteria, handicappedrampsmustbylawnotexceed8.33percentwhererailingsareinstalled;5.0percentisthemaximumwherepathwayslackrailings.Thesteeper,1:12designsmustalsohavelandingsofspecifieddimensionsatgivenrampintervals.

Mobi‐Mats: When unable to provide a walkover the City will use, if available, apolymermat that is able to createa solidwalking surface for thepublic touse toaccess the beach. Thesemats protect the dunes from erosion and damage to thesurroundingvegetation.

EliminatingDuplicativeandDune‐damagingPathstotheBeach:Onealternativetothe existingmultitude of privatewalkways between the built beachfront and thebeach is to reduce the number of walkovers and openwalkways to the shore inexchangeforamorelimitednumberofcrossovers,ramps,andwalkwaysbuiltwithstronger components and more durable materials, while at the same time

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constructedmoresustainablywithrespecttothedunesystemsoverwhichthenewelementswilltraverse.

Continuation of the City’s street‐end handicapped ramp programwill expand thenumberof general access structures thatarewell‐built andoffer thepotential foreliminating nearby duplicative and /or dune‐damaging private trails to the beachthatliebetweenthestreet‐ends.

It is therefore recommended that the City confer with property owners whereprivatepaths to thebeachhavebeen fashionedwithresultingdunedepletionandlosstodeterminewhetheragreementcanbereachedforsucheliminations–giveneasily reached alternative crossovers such as nearby street‐end accessways thatwouldservetheirresidentsorotheruserswithoutsignificantlossofconvenience.

Optionswould includetheretainingofoneprivatewalkwaymidwaybetweentwoadjacent street‐ends and acquisition by the City and dismantling of other privatewalkwaysinthisreach.Theremainingwalkwayshouldalsobeupgraded,asneeded,to yield a raised crossover built of durable and sustainablematerials that archesovertheregenerateddunesystembeneath.Thecostofthisimprovementwouldbeborneby theCity inexchange foraperpetualaccesseasement toallowsharingofaccessbytheownerwiththepublic.

4.3.3ConceptualWalkways&Footpaths

North‐south Walkways (at‐grade “Boardwalks”) Linking to Public Street‐endCrossovers andApproved Intermediate Crossovers. The foregoing improvementswouldbedependentontheconstructionofnorth‐southwalkwaysor“boardwalks”that would afford access from in‐the‐block addresses to the street‐end publicwalkways.

Here,too,accesseasementswouldneedtobepurchasedbytheCityfromagreeablepropertyowners.Topreserveownerprivacy, thenorth‐southwalkwayswouldbealigned a reasonable short distance Gulf‐ward from the buildings and gatedapproachestothebuildingentranceswouldensureaccessbyresidentsandguestsonly. The distances from the buildings the north‐southwalkwayswould be offsetwouldtakeintoaccountthedunesystemineachlocation.Wheredunesarecloseby,the walkways would be raised somewhat to clear the dune slope. The walkwaysurfaces would also be permeable, as is provided by spaced wood or othersustainable‐materialboardsorbysuchmanufacturedmaterialsas“Mobi‐Mat”.ThispermeabilitywillalsosecureconformancewiththeTexasandCityrequirementsforconstructionwithinthebuildingSetbackLines.

Convenience forbeachfrontresidentsandguests,whereexistingprivatepathsareeliminated except for a mid‐point improved and raised private crossover, wouldeasily be conserved. The time lost by the short detourswould not exceed a half‐minuteonaveragewhereamidpointcrossoverisretainedand1minuteonaveragewherenoprivatepathsareretainedbetweentwostreet‐ends.

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Such walkway consolidation was recommended in the 2007 South Padre IslandDuneGapReport.

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Applicability of Walkways–Boardwalk Concepts to South Padre Island’s Hotel /DiningDistricts: Theprincipalofprotectingandrestoringdunesbyconsolidatingwalkways and channeling foot traffic along beach‐parallel boardwalks is alsoapplicabletotheCity’shotel‐diningdistricts.Aswiththeexamplesdiscussedhere,economic benefits to the private sector, in addition to long‐term cost savings andsustainabilityinthepublicsector,arepossible.

4.3.4EstimatedAnnualCost

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Theannualcostforbeachaccessimprovementscannotbecalculatedasit’sbasedonprojectsize.Thecosttoconstructawalkoverbasedonhistoricalprojectsis$775.00alinearfoot.ThecostofMobi‐Matrangesfrom$110‐$135alinearfoot.

TheCityoperatesonabeachmaintenancebudgetsolelyfundedbyhotel/moteltax.TheCitydoesnothaveabeachuserfeeatthispointbutmaybeanecessaryoptioninthefutureforrevenue.

5.0SEMI‐ANNUALPRE‐STORMMONITORINGPROGRAM

5.1Goal

Thepurposeandneedofamonitoringprogramistoaccomplishatleasttwogoals:(1)toinformlocaldecisionmakersandthecommunityatlargeaboutthestatusandupcoming maintenance needs; and (2) to ensure that adequate, recent data isavailable to document storm losses and ensure eligibility for federal disasterassistancerelatedtonourishedbeaches.

5.2Frequency,Method,andLocation

A twice‐annual program consisting primarily of profile surveys augmented withother forms of data collection (e.g., photography, sand tracer studies, numericalsimulations)canprovideyeartoyearcomparisonsaswellasindicationsofseasonalvariationstoinformdecisionmaking.Previouslyestablishedprofilelocationscanbeusedtoensurethebestuseofexistingdataandthecosteffectivenessofnewdatacollection/analysisefforts.

In addition to periodic profile surveys, project‐specific surveys of nourishmentactivities and the progressive movement of material from designed nourishmentprisms by natural forces can allow the optimization of subsequent nourishmentactivities. Maintenance practices that result inmovement of sand resources (andseaweed) along and across the beach can be factored into monitoring tasks andresultstoprovideaclearpictureoftheprogram’sachievements.

5.3OutputReport/Recordkeeping

Thedeliverableproductsgeneratedthroughmonitoringcanincludetheprofiledatareduced andpresented graphically, comparisons to historical profiles at the samelocation, trend analyses, quantity calculations, and projected maintenance needs.The informationwill alsobe available toCity officials dealingwithFEMA inpost‐stormresponsemodetodeterminefederalassistancequalifications.

5.4Estimatedannualmonitoringcost.

AdetailedscopeofmonitoringeffortcanbedevelopedtosuittheCity’sneedsandbudget. Theorderofmagnitudecostcanbeexpectedtobe$50,000to$100,000peryear.

6.0EROSIONRESPONSEPLANFORSPICITYLIMITS

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Thespecificcontentseachlocalgovernment’serosionresponseplanaresetforthin31TACPartI,section15.17.Theseelementsareidentifiedanddescribedbelow.6.1ConstructionSetbacksFor the purpose of the ERP, the “setback” is the line seaward of which no newconstruction shouldoccur. In establishing the setback line, the state requires thatthe City utilize data obtained from the University of Texas Bureau at EconomicGeology.ThemostfurtherallowtheCityforoptionsinestablishingofbaselinefromwhichthesetbacklineismeasured.Theseoptionsare:

Thelineofvegetation(LOV) TheMeanLowTide(MLT) TheMeanHighTide(MHT) GLO‐approvedCoastalBoundarySurvey

Therulesfurtherspecifythatthesetbacklinecannotbefurtherlandwardthentheduneprotectionlineandmustprotectasmuchofthecriticalduneareaaspracticable.

TheexistenceofthesetbacklineisintendedtoimproveshorelinemanagementpracticesinTexasbyreducingtheriskstobeachfrontstructuresfromerosion,stormsandwaves.Currently,nostatewidesetbacklimitexistsinstatelaw,however,currentGLOrulesspecifythatnoconstructionispermittedseawardofthelineofvegetation,asthisiswithinthepublicbeacheasement.Inerodingareas,GLOrulesimposecertainconstructionlimitsandrestrictionswithin200feetlandwardofthemeanlowtideline.Subjectively,staterulesalsorequirethatnewconstructionalongtheGulfbeachesofthestatebelocated“asfarlandwardaspracticable.”

Forthepurposesofthiserosionresponseplan,theCityofSouthPadreIslandproposesthatitssetbacklinebetheHistoricBuildingLine(HBL)establishedbytheCityandapprovedbytheGeneralLandOfficeintheCity’scertifiedBeachAccessandDuneProtectionsPlan.TheHBLisshownapparentasthelineofretainingwallsthatfrontallexistinganddevelopedpropertieswithintheCitylimits.ThisHistoricalBuildingLine(HBL)wasestablishedonSeptember3,1981.AletterfromJohnW.Fainter,Jr.,FirstAssistantAttorneyGeneral,representingtheStateofTexaswrittentothen‐MayorGlenMcGeHee,establishingabuildingline,commonlyreferredtoastheHistoricBuildingLine,fortheCityofSouthPadreIslandBeachfrontConstructionthatwouldprovideaminimumoftwohundredfeetofopenbeachabovethemeanlowtidelineaccordingtothenavailabledata.TheletterstatedthattheAttorneyGeneralcouldreviewthelineandchangeittoensuretheprotectionoftheState’sopenbeaches.Thelinewaslocatedonamap(drawnbyChasR.HaileAssociates,Inc.,ConsultingEngineers,Houston,TexasCity,CorpusChristi,Nederland,andisdatedMarch1981)providedbytheTexasAttorney

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GeneralandisonfilewiththePublicWorksDepartmentoftheCityofSouthPadreIsland.Seepictures8a,8b,and8c.

TheHBLhasunmistakablyestablishedthepublicbeachonSouthPadreIslandandhasalsogivenbeachfrontpropertyownersanunderstandingofwheretheycanbuildupto.TheHBLalsomakesitclearwherethedunefieldshouldstarttoprovideprotectionforbeachfrontproperties.WiththeclearknowledgeofwherethedunesshouldbetheCityhastheabilitytobuildacontinuousdunelineofsimilarelevationtowithstandstormsurge.ThenaturalcycleofabarrierislandistomigratelandwardbutwithhealthydunefieldseastoftheHBLthatstoreandholdthesandvolumesneededtoprovideprotectionandsupplythebeachwithsandfollowingmajorstorms.Withtheabilitytokeepahealthydune/beachsystemseawardoftheHBLweareabletoreducepublicexpendituresduetoerosionandstormdamageloss.TheShoresubdivisionhasabuildingline(formerlycalledthe“440‐footLine”)itwasestablishedtoensurethatproposedconstructiononthesitewouldbelocatedfarlandwardofthebeachsoastoprotectthefore‐duneareaandreducetheriskofstormdamagetothesubdivision.Seephoto8d.Asadevelopedurbanshoreline,itisimpracticalfortheCitytoestablishanewordifferentsetbacklineotherthantheHBL,establishedmorethanadecadeagoanduponwhichthishighlydevelopedshorelinewasconstructed.TheCityrecognizesthatforittomaintaintheHBLasitsdesignatedSetbackLinefortheERP,theCityisobligatedtomanagethepositionoftheshoreline‐‐thebeachanddunesystem‐‐sothatexistingdevelopmentisnotsubjecttoanundueriskofdamagefromerosion,wavesandstormsurge.TheCity’sstrategytoaccomplishthisoutcome–andtherebylimitpublicexpendituresduetoshorelineerosion,wavesandstorms–istoundertakeadedicatedprogramofbeachnourishmentanddunerestoration,asdescribedinSection4.0,DesiredShorelineConditions.

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Photo8a‐AerialphotoshowingtheSouthernportionoftheCity.TheDuneProtectionLine(DPL)isinredandtheHistoricalBuildingLine(HBL)isingreen.

Photo8b‐AerialphotoshowingthemiddleportionoftheCitywiththeHBLandDPLshown.

Photo8c‐AerialphotoshowingthemiddleportionoftheCitywiththeHBLandDPLshown.

Photo8d‐TheShoresSubdivision.The“440‐footline”isingreen6.2ProhibitiononConstructionSeawardofSetbacklineInaccordancewithstaterulesandtherequirementsofthisERP,allneworrebuilthabitablestructuresmustbeconstructedlandwardofthebuildingsetbackline,tothemaximumextentpracticable.Exceptforthosenon‐habitableamenitiesspecificallyexemptbelow,allnewconstructionwithintheCityofSouthPadreIslandwillberequiredtobeconstructedlandwardofthesetbackline.

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InthisERP,theCityisnotproposingtoallowconstructionorrepairofanyhabitablestructuresseawardoftheHBL,whichservesastheSBL.6.3ExemptionsfromtheSetbackLineExemptionsfromthesetbacklinehaveonlybeengrantedfornon‐habitablestructuressuchasdunewalkovers.Dunewalkoversremovethepedestriantrafficfromthedunesthatleadtoerosionandblowoutsalongthefrontaldunes.Themostharmfulactivitythattakesplaceonthedunesisthecontinuouspedestriantrafficthatleadstolowelevations.Stormsurgemakesitswayupthepathsanderodesthepathwitheachwavewhichcaneventuallyunderminethemassivedunesthatprovideprotection(seePhoto9).

Photo9‐Showstheeffectivenessofusingdunewalkoverstokeeppedestriantrafficoffthedunes.6.4RequirementsforExemptStructures.

HabitablestructuresmaybeexemptfromtheSBLlimitationsinthreelimitedcircumstances:(1)iftheownerdemonstratesthatthereisnopracticablelocationfortheconstructiontooccurlandwardofthesetbackline;(2)theconstructionisconsistentwithanexistingsetbacklinecertifiedbytheGeneralLandOfficepriortotheERP;or(3)theconstructionconsistsofminorrepairstoanexistingstructurethatdoesnotincreasethefootprintofthestructure.

Inthiscase,theERPrequiresallnewhabitableconstructionorrepairstoexistinghabitablestructurestooccurlandwardofthesetbackline–whichistheHistoricBuildingLineasspecifiedherein.Non‐habitableamenitiessuchaswalkways,dunecrossovers,smalldecks,andotheraccessimprovementsareexemptfromtheconstructionsetbacklimit.

Staterulesestablishtherequirementsforexemptstructuresforlocalgovernmentsthatchoosetopermitmoreseawardconstruction.First,theexemptstructuremustbeelevatedtoaminimumof2feetabovetheFEMAbasefloodelevation(BFE)and

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thefoundationforthestructuremustconformtoASCEfloodresistantstandards.Inaddition,thestructuremustbedesignedforfeasiblerelocationanditmustbeplannedinawaythatminimizesimpactnaturalhydrology.TherulesalsoprohibitenclosuresbelowtheBFE.Inanyevent,allexemptstructureconstructionmustbelocatedlandwardofthelandwardtoeoftheforeduneridgewheneverpracticable.Registeredprofessionalengineersmustcertifythattheserequirementshavebeenmet.6.5EnhancingandPreservingPublicAccess.Thestaterequirementsforerosionresponseplansarealsointendedtoenhancepublicaccesstotheshorelineinadditiontoreducingpotentialpublicexpendituresforerosionandstorms.Withrespecttoaccess,therulesrequirethattheCityevaluatethevulnerabilityofaccesspointstoerosionandstormsurgedamage.TherulesrequirethattheCityupgradepublicaccessconstructionmethodsanddesignstoreducepost‐stormrepaircosts.TheCityisrequiredtocreateascheduleforpublicaccessdesignimprovementsandinventoryexistingaccessamenitiesinordertosupportanyfutureFEMApost‐stormfundingclaims.Finally,theCityisrequiredtoestablishpost‐stormbeachaccessassessmentproceduressothatdamagescanbecataloged.ThestepsfortheimprovementofpreservationofpublicaccessaredescribedaboveinDesiredConditions4.3BeachAccessPoints.Beach Access Handbook: The City inventories and documents all beach accessconditions on an annual basis to show improvements and track conditions ofexisting walkovers or mobi‐mats that may be in need of repair. Informationavailable in the document includes: photos, amenities, disabled accessibility,constructionyearandcosts,andfundingsources.Thisdocumentisusedtoplanforbudgetandgrantneeds.ItcanalsobeusedforFEMAreimbursementrequests.

Post‐stormassessmentprocedureswilltakeplaceimmediatelyfollowingthestormeventonceitissafetoenterthebeach.TheCoastalResourcesManagerwillinventoryallbeachaccessconditionsprestormandpoststorm.AlistofaccesspointsnotincompliancewiththelocalplanandBeach/Dunerules,descriptionsofrepairs,andreplacementsneededwillbecompiled.ThisassessmentwillalsobeusedforFEMAreimbursementrequestsalongwiththeannualfixedassetsreportthatvaluesallCitypropertyforthefiscalyear.6.6DuneProtection&EnhancementDuneprotectionandenhancementprojectsareacriticalcomponentoftheCity’sERP.GLOrulesrequirethattheCityspecifythetargetduneelevationandpercentvegetativecoverforitsduneprotectionandenhancementprogram.TheCityisfurtherrequiredtoidentifyspecificlocationsofdunegapsandblowoutsfor

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potentialdunerestorationprojects.Finally,theCityisrequiredtooutlinespecificdunere‐vegetationprojects,identifymeasurestoprotectthelandwardsideoftheforeduneridge,andidentifythegoals,schedules,andfundingsourcestoaccomplishitsduneprotectionandenhancementprogram.AsspecifiedunderDesiredConditions,above,theCityseekstoestablishacontinuousdunesystemwithaminimum10footelevationand60‐footbasedepth.Intheaccretingareasandinareaswherebeachnourishmenthascreatedandcansustainabeachwithof200feet,theCity’sgoalistoestablishtheduneswithaminimumbasedepthof100feet.Asillustratedabove,dunegapshavebeenidentifiedusingLIDARdataandaerialphotography.ThroughtheDuneVolunteerPlantingprogramtheCitywillbeabletofillinthesegapsandnarrowbeachaccesspathsenhancingourcontinuousduneline.TheCitywassuccessfulingettingtheDunePlantingProgramfundedthroughtheCMPCycle17.TheCitywillcontinuetoapplyforgrantfundsinordertofundthisprogram.6.7CriteriaforVoluntaryAcquisitionorBuyouts.Onerecognizedstrategytoreducepublicexpendituresfollowingstormsanderosioneventsistopurchaseorbuyoutvulnerablepropertiesalongtheshoreline.Thestaterulesallowlocalgovernmentstodevelopcriteriagoverningthevoluntaryacquisitionorbuyoutofbeachfrontparcelsandstructures.Ifsuchanapproachistobeemployed,theCitywasrequiredtoidentifypropertiesentirelyseawardofthebuildingsetbackline,provideforvoluntaryacquisition,andestablishproceduresforprioritizingpropertytobeacquired.UsingtheHBLasthesetback,nohabitablestructurescurrentlyexistseawardoftheproposedsetbackline.TheCityofSouthPadreIslandhasalsoelectedanERPstrategybaseduponmaintenanceofthebeachandrestorationandenhancementofthedunesystem.Thisapproachisanalternativetotheavailablestrategyforvoluntaryacquisitionandbuyouts.TheCityhasnotelectedtodevelopavoluntaryacquisitionandbuyoutprogramatthistime.7.0ConceptualFundingStrategy–SPIShorelineManagementProgramAsERPstrategiesarerefinedandcostestimatesaredeveloped,theCityintendstodevelopafundingstrategytosupportimplementationoftheERP.PreliminarydiscussionsindicatethatthereiscommunitysupportforestablishmentofaDedicatedShorelineMaintenanceAccounttoprovidefundsfor:

1. On‐goingbeachnourishmentprojects;

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2. Annualbeachmonitoring,includingaerialphotography,beachtransects,mapping,andassessmentoftheconditionofbeachaccesses;

3. Duneenhancementandrestorationprojects,includingthedunegapprojectsandvolunteerduneplantingprogram;

4. Publicaccessimprovementsandenhancements,includingwalkovers,parkingimprovements,consolidationofwalkoversandpathways,

5. Planning,permittinganddesigncostsassociatedwiththeprojectsabove;and

6. Minorprogramadministrationandsupportcosts.Whileannualrevenueneedscannotbeaccuratelypredictedatthistime,conceptualfundingoptionshavebeendiscussedwiththeCityandShorelineTaskForce.Ingeneral,theCityexpectstodevelopafundingplanbroadlyreflectingthefollowingprinciples:

1. SeektomaximizestateandfederalsupportfortheCity’sshorelinemanagementprogram,particularlyseekingon‐goingCEPRAandCMPgrantfundswheneverpossibleandcontinuedeffortstosecureUSACEcommitmenttothebeneficialuseprojects;

2. Seektoindentifythelocalandvisitorbeneficiariesofsoundbeach,duneandshorelinemanagementpracticesandemploy,totheextentpractical,a“beneficiariespay”strategy;

3. Seektoimplementa“blended”fundingstreamsuchthatrevenuessupportingtheDedicatedShorelineMaintenanceAccountarederivedfrommultiplefundingsourcesatthefederal,stateandlocallevel;

4. Seektodevelopalong‐termfundingstrategythatisstable,predictableandsufficienttosupportcurrentandfutureshorelinemanagementneeds;

5. Seektodevelopafundingstrategythroughacommunity‐basedprocessthatistransparent,engagesthepublicandprovidesrobustopportunitiesforpublicinputanddiscussion.

Thoughnospecificrecommendationscanbemadeatthistime,therearethreepotentialfundingsourcesatthelocallevelthattheCitymaywishto“blend”tosupportthelocalshareoftheDedicatedShorelineMaintenanceAccount:1.AdvaloremRevenues:TheCitymaywishtoconsideraShorelineMaintenanceadvaloremassessmentasonecontributingrevenuestreamtothededicatedaccount.Currently,propertyownersinSouthPadreIslandpayatotaladvaloremtaxrateof$1.962379per$100ofassessedvalue.Thistaxrateiscomprisedofassessmentsfromanumberoftaxingentitiesbesidesthecity,includingCameronCountyandtheschooldistrict.TheCity'scurrentadvaloremtaxrateis$0.2456per$100ofassessedvalue,whichisthelowestmunicipaltaxrateinCameronCounty.AmodestincreaseintheCity’sadvaloremtaxrateofthreecentsper$100wouldincreasetolocalratefrom$0.2456to$0.2756per$100value.Evenatthisincreasedrate,theCity’sadvaloremratewouldstillbethelowestinCameron

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County‐‐lessthanthatofLosFresnos,SanBenito,Brownsville,PortIsabel,Harlingen,andLagunaVista.BasedonatotalassessedvalueofpropertyintheCityofabout$2.6billion,anadditionalthree‐centadvaloremassessmentwouldgenerateabout$780,000peryearfortheDedicatedShorelineMaintenanceAccount.2.HotelOccupancyTaxRevenues:Likemostbeachresortcommunities,theCityisblessedwithadiverseandsubstantialhotelandrentalmarketsector.VisitorshiptotheCityincreasessubstantiallybeginninginthespringmonths,peaksinthesummer,andgraduallydeclinesinthewinter.Thisvisitorshippatternistypicalofmanybeachresortcommunitiesandreflectsthestronginfluenceofthebeachasthecornerstoneofthelocaltouristeconomy.Currently,hotelpatronsandshort‐termvacationpropertyrenterspayHotelOccupancyTaxesthatbenefittheCityandstate.BelowisatypicalbreakdownofHOTrevenuesonaone‐nightstayataSPIhotel:

Room at $99.00/night HOT Rate $99.00

City Occupancy Tax 8.0% $7.92

State Occupancy Tax 6.0% $5.94

City Beach Nourishment Occupancy Tax 0.5% $0.50

TOTAL HOTEL OCCUPANCY TAXES 14.5% $14.36

Outofthe14.5%occupancytaxrate,theCitycurrentlydedicatesaone‐halfofonepercenttosupportitsbeachnourishmentprogram.Giventhatasubstantialpercentageofout‐of‐townvisitorscometoSouthPadreIslandtoenjoythebeachandgiventhesubstantiallong‐termcostofbeachanddunemanagement,theCitymaywishtoconsidersomeadjustmenttotherateorallocationofrevenues.ModifyingHOTratesisasensitivesubjectandwouldrequireclosecoordinationwithhotelownersandoperatorsandotherstakeholdersbeforeanyproposalcouldbedeveloped.Nationally,theuseofHOTrevenuesasacomponentofacomprehensivefundingstrategyhasproventobeausefulandreliablerevenuesourcetosupportbeachandshorelinemanagementprojects.

3.SalesTaxRevenues:InabeachresorttownlikeSouthPadreIsland,salestaxesrevenuestypicallyincreasesubstantiallyduringthetouristseason.Out‐of‐town

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visitorsswellthesummerpopulationcontributingsubstantialrevenuestothecommunity.Attractedtothebeautifulbeaches,thesevisitorsareclearlybenefitfromawell‐maintainedbeachandpublicaccessimprovements.Asthecommunitycontinuestogrow,salestaxestypicallygrowaswell.Thoughthefinancialandcommunityissuesregardingtheuseofsalestaxrevenuesforshorelinemanagementwouldbecomplex,itwouldbeprudenttoexplorethisrevenuestreamasapotentialcomponentoftheblendedfundingstream.

Overall,theCitywouldbenefitifitcanidentifyareliableandpredictablefundingstrategytosupportitslong‐termshorelinemanagementprogram.Erosionisapersistentforcethatdirectlyandsubstantiallythreatensmanybarrierislandbeachtowns.TheresponsestrategyandfundingplanmustbeequallypersistentiftheCityistomaintainitsplaceasthepremierbeachresortcommunityinTexas.