Discharge: According to 60-year statistics of water flow in Ahwaz, Shalu Bridge, Godarlandar and Gotvand, the annual average of discharge at the site of Karun 3 Project and Ahwaz is estimated to be 302 to 727 m3/s.
Return period of spillway design flood: Karun 3 dam spillways are designed for flood passing.
Return period of diversion system design flood: diversion system is constructed to bear floods with 10-year return period.
Probable maximum flood (PMF): probable maximum flood includes the maximum flood which may probably flow in the catchment area. In basic studies of Karun 3 Project, probable maximum flood is estimated from 22400 to 27000 m3, But in complementary studies with use of the latest statistics of Karun River discharge, this sum has reduced to 15000 m3 and due to the point that Karun 4 dam is located in upstream of Karun 3, the maximum entry to Karun 3 dam reservoir is about 14147 and the maximum outlet from the reservoir would be 13200 m3.