Project objectives:

Supply of additional water for irrigation and hydropower generation by increasing the height of the Dam.

Project Components:

The exiting project components are as follows:

•  Double Curvature Arch Dam
•  Diversion tunnel
•  Spillway
•  Spillway tunnels
•  Power plant
•  Power plant tunnels
•  Irrigation outlets

Project Description:

Dez Double Curvature Arch Dam with 203 m high was built on the Dez river in 1963 . The project has three bottom outlets and two inlets for the powerhouse. The original design estimated the sedimentation in the reservoir around 840 mcm for a period of 50 years, which is equivalent to el. 290m. In 1996, the sedimentation accumulated behind the dam height was 23m, which was much higher than the anticipated height. The current studies address the possibility of increasing the dam height to provide more capacity to compensate for the sediment increase and maintain the amount of irrigation and produce power form water supply. In order to compensate for the decrease in capacity due to sedimentation, to increase the capacity, to stabilize water volume and to produce energy, relative studies were done.

Project characteristics:

• Type: double curvature concrete dam
• Height: 203 m
• Reservoir capacity (1963): 4190 mcm
• Power generation capacity: 520 MW
• Diversion tunnel: 15m diameter, 670m long

The role of Behan Sadd Company :

Consultancy and Engineering Services for the studies of the first and second stages of the project.