Neighbor closed the canal used for irrigation, what can be done?

Good Evening, Sir, we have land in galiveedu Mandal, Kadapa Dist, AP. The river water flows nearby our land. That water come into our land with the help of canal and the canal flows through our neighbor land from olden days. But now the neighbor land owner close that canal and our land not getting that water. thats why i need legal suggestion about this issue sir. Thanks in advance sir - /