Eco-Design of River Fishways for Upstream Passage:Application for Hanfeng Dam, Pengxi River, China

"Thispaperprovidesascientificapproachfortheeco-designofriverfishwaystoallowupstreammovementoffishpastnewandexistingdamsinChina.Thiseco-designapproachintegratesprinciplesoffishbiologyandengineering,ascientificfieldalsoknownasbio-engineeringoreco-hydraulics.Wedefineafishwayasastructureormechanismforconveyingfishupstreampastadam.Man-madeornaturalstreambedscanbepartofthefishway.Theproblemisdamsblockaccesstoupstreamhabitatusedforspawning,rearing,andrefuge;i.e.,damsdecreasehabitatconnectivity.Asolutiontoalleviatethisproblemistodesignfishways,preferablywhilethedamisbeingdesigned,butifnecessary,asretrofitsafterwardtoprovidearoutethatfishcanandwillusetopasssafelyupstreamwithoutunduedelay.Oureco-designapproachforfishwaysinvolveseightsteps1)identifytheprimaryspeciesofimportance;2)understandthebasicecologyandbehaviorofthesefish;3)characterizetheenvironmentalconditionswherepassageisorwillbeblocked;4)establisheco-designcriteriaforthefishway,eitherfrommanagementagenciesor,ifnecessary,developedspecificallyforthegivensite;5)identifyfishwayalternativesandselectapreferredalternative;6)whereneeded,identifyandperformresearchrequiredtoresolvecriticaluncertaintiesandfinalizetheeco-designcriteria;7)applytheeco-designcriteriaandsite-specificconsiderationstodesignthefishway,involvingpeer-reviewbylocalstakeholdersintheprocess;8)buildthefishway,monitoritseffectiveness,andapplylessonslearned.Typesoffishwaysaredescribed,showingarangeofeco-designsdependingonthedamsiteandfishspeciesofconcern.Weusetheeco-designprinciplesasabasistorecommendanapproachandnextstepsforafishwaytopassfishupstreamatHanfengDam,anexistingregulatingdamformingHanfengLakeonthePengxiRivernearKaixian,China."