Built during Sassanid era (224-651AD), it still regulates Karun river’s water and distributes it into Gargar and Shatit river branches with a ratio of 1/3 and 2/3. The dam is part of the UNESCO World Heritage registered site of Shushtar Historical Hydraulic System.
The dam is designed to limit the water discharge in Gargar canal at 1/3 of the total discharge of Karun and transfer the remainder to Shatit branch. This has a fundamental role in powering downstream water-mills and irrigation system.
Remains of a tower called Kolah Farangi can be seen on a hill overlooking this dam. It has an octagonal floor-plan and is believed to be used and monitoring site for water regulation.