Padma Multipurpose Bridge Project

Criterion Alternative 1Revetment along bankalong the riverbanks or the constructionof cross dams blocking the floodplainflow.)Long term impact on char lands(The RTW can change the flow patternsand lead to char land changes differentfrom the natural changes in the river. Forexample, long, protruding structure likehard points will change the flow patternand could be associated with additionalchar land erosion)Long term upstream impact(The RTW can change the flow patternsand narrow down the river in parts, whichis associated with additional backwatereffects and consequently longer floodingperiods. The backwater could furtherimpact on the Arial Khan flows and leadto environmental impacts by changingthe normal situation along its course.)Long term downstream impact(The RTW can change the flow patternsand attract channels in a way thatnegatively impacts on the downstreamriver, namely results in higher thannatural riverbank erosion)Alternative 2Guide bund & hard points onbankAlternative 2 modifiedGuide bund on bank, hard points onchararea of bridge due to embankment embankment due to embankmentNo or marginal impact on naturalerosion and accretion processNo or marginal impact on naturalerosion and accretion processHard points on the char will induceimmediate erosion north of the hardpoints due to diversion of existingriver channelIf any RTW interferes with naturalerosion and accretion process ofcharts, all future natural erosions ofchars will be generally perceived asthe impact of RTW and will becriticised by local community. Thelocal char community has alreadyexpressed concerns over thisalternative.No backwater No backwater Minor backwater effect increasingflooding and Arial Khan flood flowsespecially during years when thesouth channel is active870 ha maximum erosion loss at northbank in area of river widening and 830ha maximum erosion loss in area atsouth bank870 ha maximum erosion loss atnorth bank in area of riverwidening and 830 ha maximumerosion loss in area at south bank410 ha maximum erosion loss atnorth bank in area of river wideningand 830 ha maximum erosion loss inarea at south bank6-28