Introduction to Mangla Dam
Mangla Dam was completed during 1962 – 1967 as part of the Indus Basin Treaty replacement works.
The total length of these earth fill embankments is over 8 miles (13 km) with a maximum height of 454 ft (138 m) from the core trench and is 380 ft (116 m) above the Jhelum River bed level.
Total length of the Mangla reservoir periphery is 250 Miles (400 KM) and Reservoir area is 100 sq. Miles (257 sq. KM).
Cause of Mangla Dam Raising Project
Since its completion the gross storage capacity of Mangla reservoir (5.88 MAF) has reduced by about 20% due to siltation.
For optimum utilization of the Jhelum River water resources, it was necessary to regain the storage capacity that has been already lost and also make provision for future lose in storage.
Recognizing this need, a provision for raising of the dam was kept in the original design and construction of the dam.
Initiation of Mangla Dam Raising Project
Feasibility Study for the Mangla Dam Raising Project (MDRP) was completed in July 2002 by the Mangla Joint Venture (MJV) Consultants.
The Feasibility Study established that raising of the Mangla Dam by either 30 ft or 40 ft was technically feasible and economically viable.
The incremental benefits of raising of the Mangla Dam by 40 ft were relatively small as compared to substantial additional cost involved and displacement of disproportionately larger population.
In view of these considerations, it was decided to raise the Mangla Dam by 30 ft (9.1 m).Project Objectives
Main objective of MDRP is to regain the storage capacity of Mangla Dam which was reduced due to sedimentation in the reservoir.
The average annual water availability for irrigation releases will be increased by 2.88 MAF.
Benefits will include increased flood alleviation.
About 12 % increase in average annual energy output from existing power equipment.
Planning of Mangla Dam Raising Project
The MDRP involves raising of the Main Dam and ancillary dams by 30 ft.
Modification of orifices and raising of headworks of Main Spillway by 30 ft.
Construction of Control Weir on upstream of Emergency Spillway.
The power generating equipment does not require any modification as all the Ten (10) power generating units and equipment were designed for the raised conditions of Mangla Dam.
Consultancy Services
Scope of Consultancy Services
Consultancy Services are provided by the Mangla Joint Venture (MJV) Consultants for the following four phases of MDRP
: Phase I : Feasibility Study for MDRP
Phase II : Detailed Engineering and Tender Documentation
Phase III A : Bidding and Award of Construction Contract(s)
Phase III B : Construction Supervision
Mangla Joint Venture (MJV)MJV Consultants is a group of five engineering firms National Engineering Services Pakistan - NESPAK (Pvt) Limited (lead firm)
Associated Consulting Engineers - ACE (Pvt) Limited
Barqaab Consulting Services (Pvt) Limited.
Binnie Black & Veatch (BBV) of UK
Montgomery Watson Harza (MWH) Americas Inc of USA.
CONTRACTORS
DESCON Engineering
China International Water & Electric Corporation (CWE)
COMPONENTS OF WORKS
RAISING OF MAIN SPILLWAY HEAD WORKS AND SILL LEVEL OF ITS ORIFICES RAISING OF MAIN DAM AND INTAKE EMBANKMENT
RAISING OF SUKIAN DYKE
CONSTRUCTION OF CONTROL WEIR UPSTREAM OF EMERGENCY SPILLWAY
PROJECT ORGANIZATION STRUCTURE
RESETTLEMENT WORKS
Contract works . Raising of main spillway by CWER
Raising of main dam wall by descon
Raising of intakes by descon
Construction of control weir emergency spil lway by descon
Raising of sukian dyke by cwe
View of Raising of Main Spillway by CWE
View of Raising of Main Dam Wall by DESCON
Construction of Control Weir Emergency Spillway By DESCON
View of Raising Work of Intake Embankment by DESCON
Intake Structure is in Progress
View of Main Dam Wall after Raising
MANGLA DAM RAISING PROJECT CONTRACT NO. MDR-10: CONSTRUCTION OF MAIN WORKS APPROVAL FOR FINAL PAYMENT CERTIFICATE
Ressetlement works
Replacement cost of the affected houses was paid at market price.
An additional 10% was given over and above the price and the affectees were allowed to take away the salvage material of their houses.
A new city near Mirpur and four towns close to the affected areas were developed at the project cost to resettle the affectees
.A vocational training institute in the new city and four vocational training centres in the towns were established.
The existing one-lane, light traffic suspension bridge was replaced with a two-lane, heavy traffic bridge on river Jhelum at Dhangali.
SCOPE OF RESETTLEMENT
LAND ACQUISITION 16,384 Acres
POPULATION 50,000 Nos.
HOUSES & OTHER BUILDINGS 12,815 Nos.
COST COMPONENTS ( EXCLUDING IDC ) ORIGINAL ESTIMATE REVISED ESTIMATE COMPENSATION FOR LAND (Billion Rs.) (Billion Rs.)& OTHERS (Land, Trees, Economic Loss etc.) 15.0 40.5
COMPENSATION FOR HOUSES 5.0 11.0
COMPENSATION FOR OLD 1.6 2.6
AFFECTEES COST OF RESETTLEMENT WORKS 6.0
INCLUDING Rs. 3.53 BILLION RECOVERABLE FROM THE AFFECTEES ON A/C OF LAND COST PC-I COST (ORIGINAL)
Rs.62.554 BILLION.PC-I COST (REVISED)
Rs.101.384 BILLION (UNDER PROCESS FOR APPROVAL FROM PLANNING COMMISSION)
Goals Achieved EXTENT OF DAM RIASING 30 ft (9.1 m) MAIN
COMPONENTS Original Raised Reservoir Maximum Conservation
Level 1202 ft (366.5 m)1242 ft (378.7 m)
Minimum Operation Level 1040 ft (317.1 m)1040 ft (317.1 m)
Gross Storage Capacity 5.88 MAF
(7,253 Mm3)7.55 MAF (9,317 Mm3)4.67 MAF (5,760 Mm3)
* Area 100 Sq Mile (259 Sq Km)125 Sq Mile (324 Sq Km)
Main Dam and Intake
Embankment Maximum Height 454 ft (138.4 m)484 ft (147.5 m)
Crest Length 10,300 ft (3,140 m) 11,150 ft (3,400 m)
Sukian Dyke Maximum Height 144 ft (43.9 m)174 ft (53.0 m)
Crest Length 16,900 ft (5,151 m)17,500 ft (5,334 m)
Main Spillway Maximum Discharge Capacity 1,010,000 cusecs same as original (28,620 cumecs)
Elevation of Gate Structure 1234 ft (376.1 m)1266 ft (386 m)
Causes of Delay of Project
The rate of the soil from bank of the river Jhelum increased from 1rs/ton to 5rs/ton.
This caused the work to stop and was solved by Wapda Land acquisition from the local people and resettlement issues, later solved by Mangla Dam Affairs.
Benefits of mdrp
water storage capacity of the Mangla reservoir increased to 9.4 (million acre ft)
The raised Mangla Dam also playing a pivotal role in mitigating the current flood by trimming peak water inflows the additional 2.88 MAF of water will irrigate another million acres of land
The increased storage capacity will generate 644 million additional units of electricity per annum
