Iran Has no official National river. There is a vastly extended network of rivers in Iran most of which seasonally is filled with water. Some permanent rivers run from the Alborz or the Zagros to the Caspian Sea, the Persian Gulf and Oman Sea. Some Biggest River of Iran:
1. Aras River:- It runs as long as 950km inside Iran before getting to the Caspian Sea. It also irrigates many areas like Moghan Plain at the NW of Iran.
2. Sefid Rud River:- It is said to be 600-780km long from where it originates, Kurdistan Mountains. Gilan plain is a fertile area thanks to Sefid Rud. Fish is farmed in this river.
3. Haraz River:- It is a 150km long river irrigating a large plain in Mazandaran province before getting to the Caspian Sea. Trout is the major fish there.