2004 Bihar flood
According to the Central Water Commission Bagmati , Budhi Gandak , Kamla Balan , Adhwara , Kosi and Mahananda rivers were flowing above the red mark at various places , while the Ganges crossed the danger mark for the first time at Farakka Barrage . 
<triplet> Bagmati <subj> Kamla Balan <obj> tributary <triplet> Kosi <subj> Bagmati <obj> tributary <triplet> Ganges <subj> Budhi Gandak <obj> tributary <subj> Kosi <obj> tributary <subj> Mahananda <obj> tributary