Padma Multipurpose Bridge Project

Criterion Alternative 1Revetment along bank(The impact on the upstream river,notably water levels due to backwaterand changes to the flow passing downthe Arial Khan distributaries channel)Prevent bank erosion at key projectlocation(Effectiveness in preventing bank erosionin the vicinity of the Project as well asexisting roads and infrastructure.)ConstructabilityFlexibility to river changes(The flexibility to change the RTW designto the future river changes in comingfloods to maintain the constructionschedule as planned)Schedule(The operational complexity involvingcurrent-free working conditions to controlscour and sedimentation, and thenumber of seasons required)Maintenance RequirementsFrequency of Maintenance(The expected time intervals and durationof periodic maintenance, which isrequired after exceptional events orduring periods of persistent attack)Maintenance cost(The expected maintenance cost duringthe lifetime of the work, expressed as netpresent value, discounted at 12%.)Costbank does not cause significantupstream impactProtect all key project components andriver bank due to complete continuousrevetment along the bankMore flexibility.It is easier to adjust alignment ofrevetment.Slightly longer schedule and thereforeslightly higher riskLessDue to parallel flow less frequent andless extensive than for guide bundAlternative 2Guide bund & hard points onbankis not associated with majorupstream impactProtects only key projectcomponents not the river bankdue to discontinuous revetment,which creates local bank erosion.Less flexibility.Adjustment of alignment andorientation at bridge requirehigher efforts but manageableShorter schedule due to slightlyless work and therefore slightlyreduced riskMoreDue to more turbulent flow morefrequent and longer than forrevetment47 million 76 million 94 millionAlternative 2 modifiedGuide bund on bank, hard points oncharnot associated with major upstreamimpactProtects both key projectcomponents and river bank.Very less flexibility.In addition to the adjustment ofalignment and orientation at bridge,the adjustment of alignment in Charwould be difficultSimilar schedule to revetment withmore dredging in unstable charenvironmentMoreSimilar to Alternative 26-25