Doiraj Storage Dam Project

Project Purpose / Layout

The purpose of the dam is to regulate 133.6x106 m3 water in the first 25-year period and 124.6x106 m3 flow in the second 25-year period in order to irrigate about 5800 hectares of farmland in Dehloran plain, 4880 hectares of farmland in Musian plain and to supply 24x106 m3 water for industrial consumption (petrochemical).

Geographic Location

The dam site is situated in the drainage basin of the Doiraj River, about 13-km northeast of city of Musian, 22-km southeast of city of Dehloran in the southwest of Ilam province. The access road to the dam site branches off from Andimeshk - Dehloran road (16 km from city of Dehloran next to Doiraj Bridge) and then it ends to the dam site after 6 km.

Project History

The phase I study was began by drilling the exploratory boreholes at the dam site by Khuzistan Water & Power Authority in 1997, and the relevant report was prepared in 1977. The phase II geotechnical study was began by Soil & Rock Company in Jul.2001 and finished in Jan.2003. Mahab Ghodss Consulting Engineering Company supervised the good performance of all the studies.

Specific Characteristics of Project

70,000-m3 Plastic concrete cutoff

Technical Specifications of Project

Dam

Dam type

Earthfill dam with clay core

Dam height above foundation (m)

66.5

Dam crest length (m)

1360

Dam crest width (m)

8

Dam body volume (m3)

4500 x 103

Total reservoir volume (m3)

205 x 106

Active reservoir volume (m3)

124 – 165 x 106

Mean annual inflow (m3/s)

191

Spillway

Type of spillway

Free ogee

Flood discharge capacity (m3/s)

4164

Powerhouse

Powerhouse type

-

Number of units

-

Design head (m)

-

Installation capacity (MW)

-

Mean annual generation (GWH)

-

Diversion System

Type of diversion system

Tunnel  

Number of diversion tunnels

2

Length of diversion system (m)

595

Diameter of diversion tunnel (m)

5.5

Discharge capacity of diversion system (m3/s)

638

Power Tunnel 

Length of power tunnel (m)

294

Diameter of power tunnel (m)

1.8

Water Conveyance Tunnel

Length of water supply tunnel (m)

-

Diameter of water supply tunnel (m)

-

Bottom Outlet

Discharge capacity of bottom outlet (m3/s)

86.3

Intakes

Discharge capacity of irrigation intake (m3/s)

8

Discharge capacity of drinking water intake (m3/s)

-

Discharge capacity of power intake (m3/s)

-

Relocation Roads & Access Roads

Length of relocation roads (km)

-