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101-Staff Report.pdf
PUBLICWORKS DEPARTMENT CITY HALL 1010300TORRE AVENUE • CUPERTINO, CA 95014-3255 TELEPHONE: (408)777-3354www.cupertino.org CITYCOUNCILSTAFFREPORT Meeting:April 5, 2011 Subject AlternativeBridgeLocationsand TrailAlignmentsforStevensCreekCorridorProjectPhaseII. RecommendedAction AdopttheBaseAlignmentbridgelocationandageneraltrailalignmentbetweenthesecondrow of orchardtreesandthecreekriparianzonefortheStevensCreekCorridorParkPhaseII. Discussion OnJanuary18,2011,Councilauthorizedstafftoinitiatevariousactionsfortheproject, includinginitiatingthedesigneffortforAlternative4A(consistingofaneastbankcreek restorationand usingapprovedmaster planned bridgeandtrailalignment). OnMarch15,2011,CouncilheldaStudySessiontodiscussalternativebridgelocationsandtrail alignments.Aregularagendaitemwasalso heardwiththeintentofadoptingabridgealignment andgeneraltrailparameterssothatthenextphaseofdesigncouldproceedandthatfewer alternativeswould needto be studied duringtheCEQAanalysis. TheCouncil directed stafftoreport back on April5withthefollowing: ·Considerlocatingthetrailbetweenthesecondrowoforchardtreesandariparian setbackfromthecreekbank ·Analyzeadditional upstream bridgelocations ·MeetwiththeStocklmeir TaskForce ·Provideacostand designanalysisforeachalternative ·Lookat howthetrailwillintersectwithStevensCreekBoulevard OnMarch28,2011,staffmetwiththeStocklmeirTaskForceandpresentedalternativebridge locationsfortheirconsideration.Thosealternativelocations,alongwiththeBaseAlignment alterative,are depictedintheattachedexhibitsand summarized below. Bridgealternatives,numbered2,3and4,areprovidedforasExhibitAforCouncil consideration. AlternativeBridgeLocationNo. 2 Thisbridgewillneedtobeapproximately70feetinlengthtospanthecreekandprevent damagetotherootsofseverallarge sycamoreandoaktrees.Thewesternendofthebridgewill extendsubstantiallyinsidetheMeadows100footsetbackandbeapproximately50feetfromthe Meadowspropertylineandthenearestresidence.Theinstallationofthisbridgewillrequirethe removal ofanoaktreeontheeast bankthatisapproximately 28 inchesindiameter. AlternativeBridgeLocationNo. 3 Thisbridgewillneedtobeapproximately85feetinlengthtospanthecreekandprevent damagetotherootsofseverallargeoaktrees.Thewesternendofthebridgewillextend substantiallyinsidetheMeadows100footsetbackandbeapproximately60feetfromthe Meadowspropertylineandthenearestresidence.Theinstallationofthisbridgewillrequirethe removalofseveralbuckeyetreesonthewestbankanda13inchelderberryontheeastbank. An unhealthysycamoreontheeast bankwillmostlikely needtoberemovedfor safetyreasons. AlternativeBridgeLocationNo. 4 Thisbridgewillneedtobeapproximately105feetinlengthtospanthecreekandprevent damagetotherootsofaverylarge(84inchdiameter)oaktreeonthewestbank.Thewestern endofthebridgewillrestoutsidetheMeadows100footsetback.Theinstallationofthisbridge willrequiretheremovalofan unhealthysycamore on theeast bankfor safetyreasons. BaseAlignment TheBaseAlignmentbridgewillbeapproximately60feetinlengthtospanthecreekand preventdamagetotherootsofaverylarge(84inchdiameter)oaktreeonthewestbank. Severallimbsontheoaktreewillneedtobetrimmedforbothconstructionandeventual pedestriansafety.ThewesternendofthebridgewillrestwelloutsidetheMeadows100foot setback.A16inchdiameteroaktreeontheeastbankmayneedtoberemovedtoinstallthe bridge. AttheconclusionoftheStocklmeirTaskForcemeeting,themembersreachedageneraland nearunanimousagreementthattheypreferredtheBaseAlignmentbridgealternativefora varietyofreasons.Theyalsorecommendedthatthetrailberoutedthroughtheeasternedgeof theorchard,nearthecreekbutoutsideariparianzone.Thetaskforceurgedthisroutebe acceptedtoprotecttheorchardandstillprovideforanearbycreekexperiencebythetrailusers. ImportantfactorsfortheTaskForcememberswerethatthetrailseparatethecreekandorchard experiencesandthatasmuchflexibilityaspossibleberetainedforthefutureLegacyFarm. Staffwillcontinuetoworkwiththe TaskForceasthetrail designprogresses. BridgeAlternativeCostComparison AlternativeNo.BridgeandProtectiveFenceCost ImpactfromBase BaseAlignment0 2(10,000) 335,000 465,000 TheprojectbudgetcurrentlyaccommodatesanamountfortheBaseAlignmentbridgespanand the necessaryfoundationsystem. Thefoundationandinstallationcostsforthealternativeswould also be higher duetotheincreasedlength ofthe spans. Thealternativebridgelocationswouldreducethelengthofgolfprotectionfencerequiredand therebythecostoftheassociatedprotectionfence.Thetableaboveshowstheapproximatenet impacttothecurrent budgetforeach ofthealternative bridgelocations. It should be notedthattheabovecostestimates showninthetableareroughestimates. TrailAlignment TheStocklmeirTaskForcemembersalsoconcludedthatthetrailwouldcreatetheleastnumber ofimpactsifitwereroutedalongtheeastsideoftheorchardnearthecreekriparianzone. MembersofthetaskforcerepresentingtheMeadowsagreedthatthetrailcouldencroachonto the100footsetbackbutshouldnotbeplacedanycloserthanthesecondrowoforchardtrees. Thesecondrowoforchardtreesisapproximately80feetfromtheMeadowspropertyline.The taskforcemembersalsoagreedwiththe suggestionthatadditionalorchardtreescould be planted alongthewest sidetoenhance privacyifthetrailwereroutedalongthewest side ofthe orchard. Thedesignofthetrail’sintersectionwithStevensCreekBoulevardwilltakeintoaccountbike andpedestriansafetyandwillemploybestdesignelementstoaccommodatetheperpendicular intersectionandthevehicularspeedsoneastboundStevensCreekBoulevard.Measurescould employ both physicaland signageelementstolessenthe potentialforconflicts. Conclusion StaffagreeswiththeStocklmeirTaskForcethattheBaseAlignmentbridgelocationandthatan easterly orchardtrailroute strikethe best balanceforallthe stakeholdersconcerned. SustainabilityImpact Anyoneoftheproposedalternativebridgelocationsandatrailalignmentbetweenthesecond rowoforchardtreesandthecreekriparianzonewouldfullysupporttheCity’ssustainability goals. ____________________________________ Preparedby:TerryGreene,CityArchitect Reviewedby: TimmBorden,Director ofPublicWorks MarkLinder,Director ofParksandRecreation ApprovedforSubmissionby:DavidW.Knapp,CityManager Attachments: ExhibitA-BridgeLocationAlternatives ExhibitB-Stocklmeir TaskForce MeetingNotes