The construction of Mangla Dam was started in 1962 and completed in 1967.

PURPOSE OF THE PROJECT
Mangla Dam is a multipurpose project primarily meant for affecting part replacement of water supplies of three eastern rivers from Jhelum river. Besides, it is designed to conserve and control flood water of river Jhelum through significant reduction in flood peaks and volumes at downstream by incidental use of the available storage space. The other by products are power generation to meet the power demand of the country, fish culture to provide protein rich diet, tourism to provide healthy recreation facilities to the people and navigation.

PROJECT COMPONENTS
The project consists of two dams (Main Dam & Jari Dam), two dykes to contain reservoir, two spillway for outflow regulations, intake structures with five tunnels, a power house and a tailrace canal.

POWER HOUSE
Power House has been constructed at the toe of intake embankment at the ground surface elevation of 865 ft. SPD. The water to power house is supplied through five steel lined tunnels of 30/26 ft. diameter. Each tunnel is designed to feed two generating units. The power house tailrace discharges into New Bong Canal which has a length of 25,000 ft. with discharge capacity of about 49,000 cusecs, and terminates at an automatic gate control headworks at about 12 km downstream located near old Bong Escape Headworks.

Power Station was completed in four stages. The initial phase comprising of four units of 100 MW each was completed in 1967~1969. The first extension of Units 5~6 (2 x 100 MW) was completed in 1974 while second extension comprising of Units 7~8 (2 x 100 MW) was completed in 1981. The project attained its maximum capacity of 1000 MW with the final extension of Units 9~10 (2 x 100 MW) in 1993/94.

During the high reservoir level period, Mangla is able to generate 1150 MW against the rated capacity of 1000 MW due to permissible overloading of 15% whereas the capacity reduces to about 500 MW in the lean flow period (winter season) due to low reservoir level.

Salient features of various components of Mangla Dam and Power House are as under:

Mangla Dam

Type Earth-fill Max. Height (above core trench) 454 ft. 138.38 meters Max. Height (above river bed) 380 ft. 115.57 meters Crest Elevation 1234 ft. SPD 376.12 meters Length of Crest 11000 ft. 3353 meters

Reservoir

Type Earth-fill Max. Conservation Level 1202 ft. SPD 366.37 meters SPD Min Operation Level 1040 ft. SPD 317.0 meters Design Gross Storage 5.88 MAF Existing Gross Storage 4.823 MAF Design Live Storage 5.34 MAF Existing Live Storage 4.636 MAF Surface Area 100 sq. miles 259 sq. km.

Main Spillway

Type Submerged Orifice Capacity (at pool elev.of 1202 ft. SPD) 870,000 cusecs 24,630 cumecs No. of Gates 9 (Nine) Size of Gate 36 ft. wide 40 ft. high 10.97x12.19 meters

Power House

UNITS 1~4 5~6 7~8 9~10 Turbine (Francis-Vertical) Output (BHP) Rated Head (Ft. of Water) Make 138000 295 Mitsubishi Japan 138000 295 CKD Blansko (Czech.) 138000 295 Escherwyse- ACEC Belguim 138000 295 SKODA (Czech.) Generators (Umbrella Type) Output (MVA) Output (MW) Output (P.F) Output (K.V) Rated Speed (RPM) Make 125 15% overload 100 0.8 12.5 166.7 Hitachi Japan 125 15% overload 100 0.8 12.5 166.7 Skoda Czech. 125 15% overload 100 0.8 12.5 166.7 Hitachi Japan 125 15% overload 10 0.8 12.5 166.7 Skoda Czech. Transformers (3-Phase) Capability (MVA) Voltage Ratio (KV) Make 138 • 12.5 / 132   [Unit 1~2] • 12.5 / 220   [Unit 3~4] Savigliano [1&4] Skoda [2&3] 138 12.5/220 Savigliano Italy 144 12.5/220 Italtrafo [Unit-7] Skoda [Unit-8] 144 12.5/220 Skoda Czech.

Project Benefits
Besides providing timely irrigation supplies to agriculture, the project has generated 174.067 Billion units of low cost hydel energy since its commissioning. Annual Generation during 2006-2007 was 6.150 Billion KWh while the Station shared 1150 MW peak load which was 8.51% of total WAPDA System Peak.