Adynamicanalysisofthewetlandmitigationprocessandef

LandscapeandUrbanPlanning89(2009)17–27ContentslistsavailableatScienceDirectLandscapeandUrbanPlanningjournalhomepage:∗DepartmentofCityandRegionalPlanning,UniversityofNorthCarolinaatChapelHill,NewEastBuilding,CampusBox#3140,ChapelHill,NC27599-3140,UnitedStatesarticleinfoArticlehistory:Received1August2007Receivedinrevisedform19July2008Accepted3September2008Availableonline15October2008Keywords:WetlandmitigationNonetlossSystemdynamicsEnvironmentalplanningLanduseplanningEcologicalrestorationabstractSince1980,U.S.regulationshaverequiredcompensatorymitigationforwetlandlosses,oftenthroughwetlandcreationorrestoration.In1987,theNationalWetlandsPolicyForumrecommendedthatfederalpolicyshouldaimtoachieveoverall“nonetloss”ofthecountry’sremainingwetlandacreageandfunction.Controversyhassurroundedrecentreportsthatlaudtheachievementofnonetlosswhilecitingthevirtualeliminationofcertaintypesofwetlandlossesincertainareas.However,littlediscussioninthisdebatehascenteredonthedynamicnatureofwetlandlossandrestoration.Evidencehasshownthattemporallagsinwetlandrestorationcantemporarilyreducewetlandfunctionandimposehighcostsonsociety.Thispaperanalyzeswetlandlossandcompensationasdynamicprocessesthatincludetemporallagsprevalentinvariousmitigationtechniques.Here,asystemdynamicsmodelofthemitigationprocessisusedtoexplorewetlandalterationandmitigationdatacollectedbetween1993and2004fortheChicago,ILregion.Thismodelincludesvitalfactorsassociatedwithmitigationpolicy,includingmitigationfailurerates,varyingmitigationratios,andthetemporallagsandheadstartsinherentinmitigationbanking,permitteeresponsiblemitigation,andin-lieufeemitigationprograms.Resultsdemonstratethatdelaysininitiatingandcompletingrestorationactivitiesmeanthatfrequent,temporarywetlandlossescaneasilycontributetoaconsistentandconsiderablenetfunctionallossovertime.Iconcludebydiscussingmethodsforminimizingnettemporarylossesandreducingwetlandrestorationlagcosts.©2008ElsevierB.V.Allrightsreserved.1.IntroductionManystudieshaveshownthatthelossofimportantwet-landfunctions,includingcarbonsequestration,floodattenuation,wildlifehabitatandopenspaceprovision,andwaterqualityimprovement(NRC,1992,2001),canhavesignificantrepercussionsonthehydrologicalandecologicalstabilityofthelandscape(HulseyandTichenor,2000;Arnold,2006).In1987,theU.S.EnvironmentalProtectionAgency(EPA)convenedtheNationalWetlandsPol-icyForum(NWPF),awidearrayofstakeholderswhosegoalwasto“addressmajorpolicyconcernsabouthowthenationshouldprotectandmanageitsvaluablewetlandsresources(NationalWetlandsPolicyForum,1988,p.vii).”Theforumattemptedtorefo-cusUnitedStateswetlandregulationtowardsapolicyof“nonetloss,”recommendingthat,...thenationestablishanationalwetlandsprotectionpolicytoachievenooverallnetlossofthenation’sremainingwet-landbase,asdefinedbyacreageandfunction,andtorestore∗Tel.:[phone];fax:[phone].E-mailaddress:[e-mail],wherefeasible,toincreasethequalityandquantityofthenation’swetlandresourcebase(NationalWetlandsPolicyForum,1988,p.3).SincetheNWPF,thepolicygoalof“nonetloss”ofwetlandshasbecomeadrivingforcebehindwetlandsmanagementthroughouttheUnitedStates(Hansen,2006).ThewetlandimpactpermittingprogramestablishedunderSection404oftheCleanWaterActandadministeredbytheArmyCorpsofEngineers(Corps)hasbecomeincreasinglyresponsibleforsustainingnonetlosspolicy(Turneretal.,2001;Tolman,2004)byrequiringthatsomeimpactsbecom-pensatedforthroughtherestorationorcreationofwetlands.Undercompensatorymitigationregulations,somewetlandlossescanthe-oreticallybeoffsetbyrequiringpermitteesresponsibleforwetlanddestructiontocreate,restore,orpreservewetlandsinanotherarea.Inordertoaccuratelyassesstheaggregateeffectsofwetlandimpacts,aswellastheeffectsofthewetlandpermittingprogramsonthestatusofnonetloss,anysystemthattrackswetlandlossesandgainsmusttakeintoaccounttheinherentdelaysinlandalter-ationandrestorationprojects.Althoughregulatorypermitsareissuedwiththeviewthatwetlanddestructionandcompensatorymitigationareconcurrentandinstantaneous,delaysininitiatingandcompletingrestorationactivitiesmeanthatlargenumbersof0169-2046/$–seefrontmatter©2008ElsevierB.V.Allrightsreserved.doi:10.1016/j.landurbplan.2008.09.00318T.Bendor/LandscapeandUrbanPlanning89(2009)17–27temporarywetlandlossescancompoundintoaconsistent,tempo-rarynetlossofwetlandacreageandfunctionovertime.Whilesignificantworkhasaddressedtheecologicalissuesofrestorationoutcomesatthescaleofindividualwetlands(Sklaretal.,1985;Costanzaetal.,1990),littleworkhasfocusedontheaggregate,dynamicbehaviorofwetlandlossandgain(viapermittedactions)atthelandscapelevel.Asaresult,severalques-tionsremainlargelyunaddressed.Asasteadyseriesofwetlandsaredestroyedandtheircompensatorymitigationisinitiated,willthelandscapeexperienceatemporarynetlossofwetlands?Isitpossibletopreventthisfromoccurring,ortocompensateforit?Ifso,canpreventativemethodsactuallybeputintopracticeasapplicable,enforceablepoliciesatthenati