Gotvand

  • Introducing the plan
  • Basic Information
  • Technical Information
In this section the project is introduced in form of following items:
  • Targets
  • History and background
  • Location and general layout
  • River specifications
  • Specifications of catchment area
  • Dam location
  • Features
  • Important effects

Targets

Generating annual hydroelectric energy of about 4500 GW/h
Controlling seasonal floods of Karun River and upstream dams
Regulating downstream water, used for agricultural purposes
Creating tourism attractions
History and background
After studying hydroelectric potentials of Catchment area of Karun River in 1960s, the issue of developing and making big reservoirs (between kilometer 490 of the river and kilometer 800) were prospered. For developing Karun River between Gotvand and Shahid Abbaspour dams, some recommendations were presented by Harza Co. in 1967, by Monenko Co. in 1975 and by Akers Co. in 1982. The first proposed dam was in downstream of Shahid Abbaspour dam and it was Godar-Lander project which its studies were carried out by Moshanir- Lahmeyer consultants. Also other dams were studied by these Consultants which their approximate locations are as follows:
First option: River kilometer of 440
Second option: River kilometer of 419
Third option: including two sub-options in river kilometer of 383 and river kilometer of 377
Finally the contract of “Gotvand Olia” engineering services was concluded between the client and Moshanir-Kaytak consultants with the target of studying the feasibility of project execution in current location. The basic studies of Moshanir-Kaytak consultants was finished in 1997 and reviewed by Lahmeyer Co. In 2003, Mahab Qods Consulting Engineers were chosen as the project consultant for completing the studies of second phase and supervision of the operation.
Excavation of diversion tunnels and Gotvand Olia power plant began in April 1997, main civil works started in 2001 and the river was diverted into tunnels, after completion of upstream cofferdam in April 2003.
 
  • In 1997 basic studies of the project was finished by Moshanir-Kaytak J/V and reviewed by Lahmeyer Co.
  • In April of the same year the water diversion operation began with excavation of the diversion tunnels.
  • In 2003 karun River was diverted.
  • In 2003 upstream cofferdam of the project was constructed and excavation activities of power house started.
  • In autumn 2005, first power station’s draft tube installed in fourth unit.
  • In January 2006, embankment operation of clay core of dam body began.

Location and general layout

Location & general layout of projectGotvand Olia hydroelectric power plant project is located in 48° and 56¢ and 10² of east and 32°, 16¢ and 8² of north. It is situated in 380 kilometers of Karun River mouth and is distanced 10 kilometers to north-east of Gotvand city in Khuzestan province.

 

 

 

 

 

 

 

 

River specifications

Karun River originates from southern Zagros Mountains in Koohrang, Armand, Khorasan, Vang and Bazoft areas and after a distance of 80 kilometers along north-east to south-east, in Khorramshahr, joins Arvanrood and pours to the Persian Gulf.
Considering the discharge, this river is the greatest river of Iran. Karun River’s average annual long-term discharge, in the area of dam construction is 453 m3/s and its annual discharge is more than 14 billion m3.

Specifications of catchmnet area

Specifications of catchmnet areaMeasurement of the catchment area at the site of dam construction is almost 32425 km2, annual discharge of Karun River at the site of dam is about 453.9 m3/s and annual average rainfall is approximately 372.7 mm.
 
 
 
 

Dam location

Dam locationAs you can see in the picture, this dam is very high and it is constructed at the final points of Karun River entering into Khuzestan plain and in its downstream no other reservoir dam will be constructed.
 
 
 
 
 
 
 
 
 
 
 

Features

  • The highest rock-fill dam being constructed
  • It has the biggest reservoir after Karkhe dam
  • It is the greatest water reservoir on Karun River
  • It is the last dam and power plant in downstream of Karun River
  • It has a decisive role in controlling upstream power plants and dams
  • It has the biggest water transfer tunnels considering the area of cross section and length
  • It generates the biggest amount of hydroelectric energy in the country
  • It has one of the deepest sealing walls among the world rock-fill dams
  • It has a unique compound system of sealing and sealing curtain

Important Effects

Gotvand Olia dam and power plant project has an important role in employing native manpower and has been capable of direct and indirect employment of 6000 people. After complete operation of this project, the capacity of country’s electricity generation will increase considerably. This capacity can be effective in industrial and civil electricity provision. In addition to that an important resource of water supply will be available with 4.5 billion m3 capacity and it will have extraordinary effect in growth of water relevant industries, especially fishery. It also supplies water to farms and will have a vital role in creating natural tourism attractions.
Totally the most important cultural, social and economical effects of this project are as follows:
 
  • Job-creating
  • Creating tourism attractions
  • Increasing the country’s hydroelectric capacity
  • Growth of Hydroelectric technology and industry
  • Increasing the capability of domestic consultants and contractors
  • Activating the domestic manufacturers of energy-related equipments
  • Promoting the international position of the country, considering the promotion of country’s electricity and water industry
  • Indirect elimination of deprivation through growth of the country’s electricity resources
  • Providing a big water reservoir for several purposes such as drinking, irrigating farms and fishing industry development
  • Securing downstream lands against destructive floods of Karun River
In this section the project basic information is presented in form of following items:
  • Topography
  • Meteorology
  • Hydrology
  • Flood
  • Water quality
  • Sedimentation
  • Planning the water resources
  • Geology
  • Seismicity
  • Dam reservoir

Topography

River wall gradient is variable from 40 to 65°. The valley is generally V-shaped and is symmetrical. High altitudes of the project site reach to almost 450 meter.
 
 
 

Meteorology

Within the project zone limit, winters are mild and short and summers are hot and long. The average annual temperature in the region is 32.5° and the minimum average annual temperature is about 20° C. Dam site is equipped with a meteorology station and the annual average rainfall is about 372.7 millimeter.
 
 
 

Hydrology

Measurement of catchments area at the site of construction is about 32425 km2 and four hydrometer stations are installed in site of Godar, Gotvand, Shooshtar and Lali dams.

 

 

 

Flood

Studies related to the flood are not finalized yet.
But different floods and their returns period are as follows:
 
 
 
 
 
 

Water quality

Studied zone have geological and physiological diverse structure and several geological structures proportionately affect water quality. TDS in studied zone is variable between 240 milligram/liter to 740 milligram/Liter.

 

 

 

Sedimentation

River sediment volume after 100 years is about 535 million m3. This amount is totally 15% of water volume of reservoir and has 43 m of height.

 

 

 

Planning the water resources

According to the studies by Moshanir consultant; in case of 1000 MW power generation, power house operation is recommended to be 11h and 20m and in case of 2000 MW, power house operation is recommended to be 6 h. These figures should be reviewed carefully in future.

 

 

 

Geology

Dam structure at bed-rock has an anticline, which its two wings slope are toward abutments. The bed-rock is from Aghajary Sazand and includes stone-sands, stone and clay layers. In both abutments Aghajary Sazand is covered with Bakhtiary Sazand conglomerates.

 

 

 

Seismicity

Dam construction site as one of geological seismocity zone of Zagros is highly potential of earthquake. Most of huge earthquakes in this zone happen up to 1500 m of heights. Historical important earthquakes have happened in 840 in Ahwaz and in 1052 in Bagh Malek which were 6.8 Richter and the earthquake of Zagros which was 6.5 Richter. Important faults near the construction area are Pir Ahamd fault and... Certainly faults of   Golestan, Togah, Lali and Masjed Soleiman are some of faults in 60 km distance range of the site, which can have seismocity potential.
The maximum acceleration of geo-structure for different levels is as follows: 
 
  PGA
CBL DBL  MDL
Horizontal 0.155  0.27 0.361
Vertical  0.101 0.197 0.275

 

Dam reservoir

Reservoir volume in PMF level (244 m) is about 5.17 billion m3. At maximum operation level that is 234 m, the volume is approximately 4.34 billion m3. Gotvand dam reservoir is located in a region with the length of 90 km within the area including Aghajary, Bakhtyari and Gachsaran Sazands.

In this section the technical information of the project is presented in form of the following items:

  • Dam body

Body specifications
Reservoir specifications
Diversion system
Instrumentation
Spillway
Quarries and their specifications

  • Powerhouse

General specifications of powerhouse
Specifications of powerhouse equipments
Specifications of powerhouse building
Specifications of powerhouse outlet tunnels
Specifications of powerhouse waterways

  • Technical specifications of post and switchyard

  • Water transfer tunnels

Specifications of tunnels
Intake structures
Outlet structures

  • Access roads and bridges

  • Complementary operations

Body specifications

Item Quantity
Dam type Rock-fill with clay core
Height from foundation 180 m
Crest length 760 m
Crest width 15 m
Foundation width 1075 m
Total volume of the body 28.5 m
Sealing grouting width 450 000 m
Area of sealing wall 42 000 m2 
Foundation grouting width 250 000 m
Grouting and access gallery length 3750 m 
Volume of soil and cement 500 000 m3

 

Reservoir specifications

Item Quantity
Total volume of reservoir 4.5 billion m3
Area of reservoir  96.5 km2 at +234 masl
Length of dam lake 90 km at +234 masl
Width of dam lake  1.1 km
Normal level 230 masl

 

Diversion system

Item Quantity
Location  Left bank of the river
Numbers of diversion tunnels 2
Length of diversion tunnels  Right: 1453 m
Center: 1514 m
Left: 1563 m
Tunnel diameter after lining 9.5 m
Open-cut excavation volume 2.2 million m3
Underground excavation volume 550 000 m3
Cross section U shape
Type of lining Reinforced concrete
Tunnel excavation diameter 11 m
Discharge capacity 4200 m3/s
Type, height and volume of upstream cofferdam Rock-fill with clay core, 82 m and 3.5 million m3
Type, height and volume of upstream cofferdam Rock-fill with clay core, 23.5 m and 400 000 m3 

 

Instrumentation

Dam body instrumentation

 

Piezometer in foundation Hydraulic piezometer of body
Pore water pressure cell of foundation  
Pore water pressure cell of dam body  

 

Spillway

Item Quantity
Type of spillway OG gated with water chute
Location Left bank
Type of gates Radial
Numbers of gates 4
OG level +218
Width of spillway 72 m
Discharge capacity 17500 m3/s
Diameter of gates 15 by 17 m
Concrete placement volume 700 000 m3
Excavation volume 19 million m3

 

Quarries and their specifications

Type of materia Location of quarry
Fine-graded material Emamzade Zeid quarry with the distance of 8 km from the site
Drainage material Beneheydar quarry with the distance of 11 km from the site
Fin-graded filter material Kohang quarry with the distance of 57 km from the site
Concrete material Beneheydar, Kohang and Andimeshk quarries
Rip-rap material Manghati and Chenare quarries both with the distance of 110 km from the site

 

General specifications of powerhouse

Item Quantity
Type of powerhouse Surface
Capacity 1000+1000 mw
Average annual generation 4500 GWh
Turbine type Francis with vertical axis

 

Specifications of powerhouse equipments

Item Quantity
Numbers of turbine 4+4
Power of each turbine 254 MW
Output in nominal condition 94.4 %
Height of turbine design 141 m
Discharge of turbine in nominal condition 193 m3/s
Turbine manufacturer Voith of Austria Azarab Arak
Numbers of transformers 12+1 (spare) for 4 units 24 for 8 units
Nominal power of each transformer 100 MVA
Nominal second voltage of transformer 400 KV
Numbers and type of generators 4+4 vertical synchronic
Output power of each generator 278 MVA
Nominal voltage of each generator 15.75 KV
Rotation speed of generator 187.5 rotations/minute
Nominal current of generator 10191 A
Generator manufacturer Elin of Austria
Pars Generator
Transformer type OFWF
Basic nominal voltage 15.75 KV
Cooling system water

 

Specifications of powerhouse building

General specifications of building:
(considering development plan)
 
Length of the building Width of the building Height of the building
200m 50m 70m

Item Quantity
Excavation  3 million m3
Reinforcement  22 000 tons
Structural and filling concrete placement 300 000 m3
Heavy metal works 1300 ton

 

Specifications of powerhouse outlet tunnels

In this regard no data exists.
Specifications of powerhouse waterways
In this regard no data exists.
 

 

 

 

 

 

 

Technical specifications of post and switchyard

Type AIS
Voltage level 400 KV
Numbers of high voltage lines 4+2 (development phase)
Input feeders 4

 

 

Specifications of tunnels

Water transfer tunnels

Item Quantity
Length of water transfer tunnel 1400 m
Diameter of intake transfer tunnel 11 m
Type of lining 900 m concrete
500 m steel
Numbers of penstocks 2 series for first phase
4 series for second phase
Length of each penstock 500 m
Average diameters of penstocks 7 m
Numbers of surging tanks 2 series for first phase
2 series for second phase

 

Depth outlet

Item Quantity
Ceiling crane 40 tons
Emergency gate (equipped with hydraulic motor) 1 set
Dimension of gates 3 by 4 m
Service gate (equipped with hydraulic motor) 1 set
Dimension of gates 3 by 4 m
Metal lining 1 set
Weight of metal lining 900 tons

 

Intake structures

Hydro mechanical specifications of intake structure

Item Quantity
Numbers of intake 4
Width  11 m
Height  26 m
Water filling level 154
Maximum design discharge 900 m3/s
Design head 90 m
Gate crane 150 tons
Course of gate crane  100 m
Numbers of stop log gates 1 set
Width of the gate 7 m
Height of the gate 12 m
Minimum operation level 190 m
Trash rack type Fixed
Course of trash rack system 7 m
Numbers of wheeled gates 4 sets

 

Outlet structures

Item Quantity
Gate crane 30 tons
Stop log gate 2 sets
Dimension of gates 9 by 6 m

 

Access roads and bridges

1- Technical specifications of access roads

Name of the road Average width (m) Length (km)
Substitute road of submerged area and Lali-Masjedsoleiman 9 20 000
Access road to chute  9 9000
Access road to dam crest from left bank 11 5000
Access road from regulating dam to construction site 9 10 000

Technical specifications of the bridges

Name of the bridge Width (m) Length (m) Type of structure
Lali big bridge 14.5 480  
Gotvand city bridge 11.5 260  
Permanent bridge of the site 13 150  

 

2- Technical specifications of access tunnels

Name of the tunnel Width (m) Length (m) Height (m)
Emamzade Zeid tunnel  10 700 7
Access tunnel to spillway excavations 10 360 7
Access tunnel to water transfer tunnels 10 970 7
Access tunnels to grouting galleries 6 4000 5

 

Complementary operations

Lateral buildings:

Construction activities of the client’s office and the residential building of equipment contractor are finished and they are handed over temporarily. Sport complex, supervisors and client’s residential building and VIP is in finishing stage. Parallel to that the civil works of the main site and the structure of feasibility building are about to be finished. In the mean time sewerage system of Emamzade Zeid complex is being installed and all of the buildings of equipment contractors are handed over to Engineering Affairs Dept.

    Post Address

  • Post Address : No.3.BIDAR st. AFRICA junction, MODDARES Exp,Way TEHRAN - Post Code: 19649-13581, IRAN
  • Phone : +98 (21) 27823113
  • Fax : +98 (21) 26213732
  • e-Mail :