Flood Modelling in Waidina Tributary, Fiji Islands

Abstract

Rewa River is the widest river and the second longest river in Fiji Islands. It is in the islands of Viti Levu. The river is 145 km in length and starts from the highest peak of the island, Tomanivi. Rewa River experiences frequent floods. However, a detailed flood model for Rewa River is still to be tabled. This paper briefs the flood modeling of part of Waidina tributary of the Rewa River. US Army Corps Engineers HEC-RAS hydraulic model is being successfully applied to the Rewa River and initial results are drafted for the Waidina tributary. These results are promising; however, a completed flood model should be developed for sound conclusions. Inundation top widths due to a random flood were presented. These inundations can effectively be used to inform the residents in the vulnerable areas in a flood event. In addition, the final expected results can be used for the flood protection structural measures.