Working for wetlands

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SANBI Working for Wetlands

•Nationwideprogrammetorehabilitatewetlands

•StartedinWorkingforWaterasalienclearing

•AnnualbudgetofA$9.7million

•UsesSMMEprinciples

•Restore+100wetlands/year

•Creates+2100jobs/year

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Project overview•ClientisSouthAfricanNationalBiodiversityInstitute(SANBI)

•Professionalfees:A$2.4million

•3yearappointment

•Aureconinvolvedcountrywide(severalofficesthroughoutSouthAfrica)

•Wetlandecologistssub-consulttoAurecon

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Typical problems in wetlands

•Headcuterosion

•Artificialdrains

•Incisedchannels

•Excessivesediment

•Man-madediversions

•Alieninvasion

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Why rehabilitate wetlands?

•Restoreitsnaturalfunctioning

•Re-hydratebyliftingthewatertable

•Increasewaterstorage

•Improvewaterquality

•Increasebiodiversity

•Aesthetics&tourism

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Aurecon’s role

•Consultingandplanningservices.

•Engineeringdesignof±400structuresperyear.

•Coordinatedlargeteamconsistingof -Environmentalpractitioners -Engineers -WetlandEcologists -SANBIProvincialCoordinators

•Complywithlegislationandobtainenvironmentalandwateruseauthorisations

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Design principles

•Visualdeterminationofannualfloodlevels

•Hydraulicdesignfordrownedstructuresusingsimpleweircalculations

•Standardisedstructuraldesigns

•Component-basedconcreteweirs

-Bookofstandarddetailsforeachcomponent ofaweir

-Eachdetailisforadifferentsizeofcomponent

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Tsitsikama

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Risk

•Highriskbutlowcostoffailure(nodamageincurredbyfailures)

•Projectgearedtowardsrepairingfailedstructures

•Inexperiencedcontractors

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Before and after

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Before

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After

ContactAndré GörgensWaterResourcesManagementLeader,Aurecon+27215265704Andre.Gorgens@aurecongroup.com