Several active, defunct or dead distributary channel systems occur on the delta plain of the Mahanadi delta. They are arranged into four successive growth-stages of the delta. The new development of a distributary channel system has tended to occur on the south of the pre-existing channel system. In addition, within a distributary channel system, it is generally observed that the branch to the south becomes more active than the branch to the north. Such tendencies are interpreted as the result of the control of the prevalent wind. The southerly prevalent wind blows river-bed sand and piles it up on the northern bank of the channel. Consequently the northern bank of the channel becomes higher than the southern bank. At the branching point of a channel, the bed of the northern branch is raised up by the southerly wind action. Hence, the water has a tendency to prefer the southern branch. The southern branch thus becomes an active branch, whereas the northern branch gets choked at the bifurcation and becomes defunct with time. As a result of such effects of the wind action, the southern bank of the southernmost branch of the distributary channel system tends to be breached more easily and the new channel system preferably develops on the south of the pre-existing channel system.