462s-4

Chapter Four Description of the Study Area 122

CHAPTER 4

DESCRIPTION OF THE STUDY AREA

The working mathematical model described in chapter 3 has been developed for the optimum

operation of the Indus River multireservoir system of Pakistan. The Indus River System

comprises of 3 storage reservoirs (Tarbela, Mangla and Chasma), 16 barrages, 12 inter-river

link canals, 2 major syphons and 43 canals as shown in Figure 4.1. It is the largest integrated

irrigation network in the world, serving about 34.5 million acres of contiguous cultivated

land. The total length of main canal alone is about 58,500 km. The flows of the Indus River

System constitute the dominant surface water resources of Pakistan having total area of

803,900 km2 (310,000 mi2). Indus River basin is comprised of about 94,600 km2 (364,700

mi2) of catchment area.

The system plays an important role in the agricultural sector of the country, which employs

about 55% of the country's labour force, accounts for 26% of the gross domestic product

(GDP) and contributes about 26% of the export earnings (WAPDA 2004). The population of

Pakistan is growing rapidly. Therefore there is an urgent need to develop a viable and

efficient mechanism for the optimal utilization of water from the Indus River System for a

sustainable supply of water to irrigation. The methodology described in chapter 3 is applied

to Indus River System and tested for its effectiveness for the optimal utilization of water

from the system for a sustainable supply of water to irrigation.

4.1 Rivers in the System

Indus Basin drains Himalayan water into the Arabian sea. It consists of Indus River and its

five left bank rivers including Jhelum, Chenab, Ravi, Sutlaj and Bias in addition to Kabul

river lying at the right bank. Some pertinent details of the Indus Basin rivers are given in

Table 4.1.


Figure 4.1 Indus River System and surface storage


Table 4.1 Details of the Indus Basin rivers (WRMD 1981, WAPDA 2007)

Rivers Catchment Area (sq mi)

Mean annual Runoff (MAF

Minor Rivers

Western Rivers

Indus at Kalabagh 110,500 91.82 Siran, Kunar,

Kabul at Nowshera 2600 21.26 Swat, Pangkora,

Jhelum at Mangla 12,900 22.80 Kohat, Kurram,

Chenab at Marala 11,400 25.85 Gomal, Zhob,

Panjnad, Nari,

Eastern Rivers

Ravi (in Pakistan) 3,100 5.00 Bolan, Streams

Sutlaj (in India) 18,550(47100) 3.97 of Kactchi Plains

Bias (in India) 6,500 -

The Indus Basin Irrigation system is schematically shown in Figure 4.2. A number of small

tributaries also join these rivers. The catchment area of Indus River is unique and includes 7

worlds highest ranking peaks such as K-2 (28,253 feet), Nanga Parbat (26,600 feet) and

Rakaposhi (25,552 feet) in addition to 7 glaciers including Siachin, Hispar, Biafo, Batura,

Barpu and Hopper.


Figure 4.2 Schematic Diagram Indus Basin Irrigation System (WAPDA, 2006)


A brief description of the major Indus Rivers is given below.

4.2.1 The Indus River

Indus River originates from the north side of the Himalayas at Kaillas Parbat in Tibet having

altitude of 18000 feet. Traversing about 500 miles in NW direction, it is joined by Shyok

river near Skardu (elevation 9000 feet). After about 100 miles in the same direction, it

reaches Nanga Parbat and joined by the Gilgit river at an elevation of 5000 feet. Flowing

about 200 miles further in SW direction, the river enters into the plains of the Punjab

province at the Kalabagh (800 feet). The Kabul river, a major western flank tributary, joins

with Indus near Attock. The Kunar which is also called Chitral river joins Indus below

Warsak. About five miles below Attock, another stream Haro river drains into the Indus

River. About seven miles upstream of Jinnah Barrage, another stream called Soan river joins

with Indus. The tributatries of Indus rirves are detailed in Figure 4.3. Its hydraulic

characteristics are presented in Table 4.2

Table 4.2 Hydraulic Characteristics of Indus River and its Tributaries (Ahmad 1993)

Catchment Slope in Average Annual Area Mountain Discharge Sediment

River

Observation Station

Length (miles

(Sq miles) (ft/mile) (MAF) (acre-ft)

Indus Darband 800 103,800 35 59.5 85,441

Indus Kalabagh 925 151,200 - 89 143,744

Kabul Warsak 200 2,600 30 12.5 24,741

Kabul Munda(Swat) - 1,600 - 2.36 2,424

Siran Thapla 60 1,100 35 0.141 644

Haro HasanAbdal 30 2,400 66 0.82 1,044

Soan Mukhad Road 75 4,800 14 0.8 4,934

Kurram Kurram 117 2,663 25 0.47 12,879

Gomal Kot Murtaza - 13,900 - 0.435 550


Figure 4.3 The Indus and its tributaries (WAPDA 2007)


4.2.2 The Jhelum River One of the important Eastern river draining into the Indus River System is Jhelum river

which originates from Pir Panjal and flows parallel to the Indus at an elevation of 5500 feet

(See Figure 4.3). About 2300 sq mlies of the alluvial land of Kashmir Valley is draining into

the Jhelum river. The river flows through Dal and Wular lakes. On emergence from Wular

lake near Baramula, it runs through an eighty miles long gorge at an average slope of 33 ft

per mile. Near Muzafarbad, at Domel, it joins with Nelum river which is comprised of about

2800 sq miles of hilly area lying on the eastern side of Nanga Parbat.

Another tributary called Kunhar river joins with Jhelum river about five miles below Domel.

Two other small rivers (Kanshi and Punch) join with Jhelum between Domel and Mangla,

and Punch enters into it about seven miles above Mangla at Tangrot. Below Mangla, several

flood water streams join with the Jhelum river. Salient features of Jhelum river along with its

tributaries are given in Table 4.3.

Table 4.3 Salient features of Jhelum river and its tributaries (Ahmad 1993)

Observation Length Catchment Average Annual River Station Area Discharge Sediment (miles) (Sq miles) (MAF) (acre-ft) Jhelum Domel 180 5,250 11.4 10,172Jhelum Mangla 350 13,180 23 44,071Kishan Ganga Muzaffarbad 150 2,600 6.1 5,224Kunhar GarhiHabibullah 100 1,080 2 2,861Kanshi Gujar Khan 30 - 0.36 293Punch Palak 80 1,520 2 5,678Kahan Rohtas 40 470 0.037 425

Topography and Landform The catchment lies on the southern slopes of the Himalaya mountains. About 82 percent area

is higher than 400 ft. above mean sea level (AMSL) whereas about 28 percent area is higher

than 10,000 ft. AMSL. The catchment is bounded by Muree Hill range (8000 ft. AMSL) on

the western side, whereas in the north it is bounded by the Great Himalaya mountains and

contains the Vale of Kashmir. North of the Vale of Kashmir the mountains lead upward

towards the snows and glaciers of Nanga Parbat (stands at 26,660 ft. AMSL). At the damsite

the river passes through the foothills of Siwalik range and enters the Punjab plains.


Basin Characteristics The length of the main river from the most remote point to the outlet has been estimated to be

about 260 miles. Basin shape is numerically calculated with the help of Horton's method and

estimated as 0.190. This value indicates an irregular basin with comparatively moderate

peaks. Using different methods commonly used in drainage basin studies, various

dimensionless catchment parameters, useful in predicting inflow in a river have been

estimated for the basin. As a result elongation ratio, compactness coefficient and circularity

ratio is worked out to be 0.700, 1.413 and 0.501 respectively.

Climate The climate of the basin may be divided into four seasons, the winter monsoon

(December - February), the hot weather period (March - May), the summer monsoon

(June - September) and the transition period (October - November). In winter monsoon

the precipitation over the major part of the basin occurs in the form of snow. It accumulates

until temperatures rise in April, May and June. The snow melt contribution to the river flows

at Mangla is normally maximum in June. The months of heaviest rainfall are August and

September (Figure 4.4). Mean annual precipitation at Jhelum has been estimated to be 31.20

inches (1950-2008) (Data Source: Surface Water Hydrology Project; WAPDA). Heavy

floods due to higher rainfall are witnessed and maximum was recorded 1,100,000 cusecs on

August 1929. However, Mangla dam on Jhelum river was designed on a Probable Maximum

Flood (PMF) of 2,600,000 cusecs with a return period 240-years.


Precipitation at Jhelum(1950-2008)

0123456789

10

Jan Feb Mar Apr May June July Aug Sep Oct Nov Dec

Prec

ipita

tion

(Inch

)

Figure 4.4 Mean monthly recorded precipitation at Jhelum station of Pakistan Meteorological

Department

4.2.3 The Chenab River Chenab River is one of the major rivers which contributes appreciable water into the Indus

River System. It originates from Kulu and Kangra districts of Himachal Pardesh, a province

in India. In the upper reaches, Chandra and Bhaga are the two main streams of Chenab, rise

on opposite side of Baralcha pass at an elevation of about 16000 feet AMSL. These streams

join at Tandi located in Jammu and Kashmir. Here the elevation is 9090 feet AMSL. The

river after traversing about 400 miles of mountain regions opens out into the plains near

Akhnur. The river enters in Pakistan near Diawara village located in Sialkot district. Chenab

flows through alluvial plains of the Punjab province covering a distance of about 3398 miles.

It joins with Jhelum river at Trimmu. And finally the Jhelum and Chenab, after meeting Ravi

and Sutlej rivers, drain into Indus at Mithankot about 40 miles below Punjnad.

There are 12 major tributaries of the Chenab namely Chandra, Bhaga, Bhut, Maru and

Jammu in India and Tawi, Manawar Tawi, Doara, Halse, Bhimber, Palkhu and Aik and

Bhudi Nallah join in Pakistan. Length of Chenab is about 772 miles and its catchment is

about 26,079 sq. miles. About 10,875 sq. miles lie in Jammu ans Kashmir state, 1735 sq.


miles in India and 13,469 sq. miles in Pakistan. Chenab river is life line of the Punjab

province. Dependable supplies can be withdrawn while the river remains at a high stage from

June to September. Chenab starts rising in the later part of May and the flow becomes over

50,000 cfs in June. The high flows continue till the middle of September, the peak discharge

months being July and August.

On Chenab river, no dam is constructed by Pakistan due to topographic conditions. India has

constructed a dam at Salal for hydro electric in Jammu territory about 40 miles upstream of

Marala barrage. In Pakistan, following barrages are located on the Chenab river.

Marala Barrage - Feeds upper Chenab canal and Marala Ravi link Khanki Barrage - Feeds Lower Chenab canal. Qadirabad Barrage - It is a level crossing for Rasul Qadirabad and Qadirabad

Balloki link.

Trimmu Barrage - Feeds Haveli link, Rangpur canal and Trimmu Sidhnai link. Punjnad Barrage - Feeds Panjnad and Abbasian canals.

4.2.4 The Ravi River Ravi is one of the 5 Eastern tributaries of the Indus River System. Its catchment is about

3100 sq.miles. According to Water Treaty 1960 between India and Pakistan, India has full

right to divert all its flows for the development. Therefore arrangements have been made by

India to utilise the water of Ravi. The river originates from the basin of Bangahal and drains

the southern slopes of the Dhanladhar. Below Bangahal, the river flows through the valley of

Chamba. The river leaves the Himalayas at Baseeli. In the mountains area of 130 miles long,

the total drop is 15000 feet about which is 115 feet per mile. Its average slope is 45 feet per

mile. The Ravi enters Pathankot at Chaundh and forms a boundary between India and the

state of Jammu and Kashmir for 23 miles. The important tributaries of Ravi river are given in

Table 4.4.


Table 4.4 Hydraulic Characteristics of Tributaries of Ravi joining within Pakistan (Ahmad,

1993)

Length Catchment Area Average Slope

per 1000 ft Maximum Discharge Tributary

(miles) (sq miles) (miles) (cfs) Ujh 80 675 31.6 249,000 Bein 48 346 5.9 128,000 Basantar 45 224 6.4 83,000 Degh 160 456 7.4 100,000 Hudiara 62 53 0.25 10,000

4.2.5 The Beas River It is one of the Eastern tributary of the Indus. The length of the river is about 247 miles. It is

the shortest river of the system and its flows are under the control of India as per Indus Water

Treaty 1960. Pandoh and Pong dams have been built over it by India. The catchment area is

about 6500 sq miles.

4.2.6 The Sutlej River It originates from Western Tibet in the Kailas mountain range in India and flows through the

Panjal and Siwalik mountains ranges. Then it enters the plains of Indian Punjab. The length

of the river is about 964 miles and its catchment is about 47100 sq miles. According to Indus

Water Treaty 1960, India has full right to use the flows of Sutlej river. India has built dams

and barrages after Independence. Barrages existing in Pakistan were built before

Independence. Important tributaries, dams and barrages of Sutlej river are given in Table 4.5.

Table 4.5 Hydraulic Characteristics of Important Tributaries of Sutlej (Ahmad 1993)

Length Catchment Area Average

Slope Highest Altitude Tributary

(miles) (sq miles) (ft/mile) (feet) Spati 115 3915 89 20,000 Gambhar 40 342 114 6,000 Soan 50 495 46.8 3,340 Sirsa 32 280 83.5 3,660 White Bein 88 1485 11.5 10,700 Black Bein 90 945 13.5 1,900 Beas 290 6200 42.7 13,050 Rohi 24 715 - -


4.2 Reservoirs/Dams of the Indus River

The major reservoirs/dams of the Indus River System are Tarbela dam, Mangla dam and

Chasma reservoir.

4.3.1 Tarbela Dam Tarbela dam is world's biggest earth and rock fill dam and was completed in 1974-75 and is

located on the Indus River. The dam is 485 feet high and 9000 feet long. A 100 sq. mile lake

is capable of conserving gross quantity of 11.7 MAF of water. Installed power generation

capacity is 3500 MW. It has two spillways (see Figure 4.5), four tunnels for power

generation on the right bank and one for irrigation on the left. The gross capacity has now

reduced to 9.745 MAF from its original capacity 11.7 MAF (WAPDA and NEAC, 2004).

Tarbela reservoir is shown in Figure 4.6. Elevation capacity curves of the reservoir are one

of the important input parameters in reservoir simulation and it is shown in Figure 4.7.

The main objectives of the Tarbela dam are i) To augment and regulate the supply of Indus

River water to irrigate the land of Indus Basin System. ii) Hydropower generation. iii)

Incidental Flood Regulation. Based on the irrigation demands, reservoir operation studies

were conducted by WAPDA to develop operating rule curves for the dam operation

(Tippetts-Abbett McCarthey-Stratton consulting engineers, 1984).


Figure 4.5 Tarbela dam auxiliary spillway (Photo taken on 09-May-2008)

Figure 4.6 Tarbela reservoir (Photo taken on 09-May-2008)


1400

1450

1500

1550

0 1 2 3 4 5 6 7 8 9

Capacity (MAF)

Elev

atio

n (ft

)

2030

2040

2002

2020

2015

2012

Figure 4.7 Elevation-capacity curves for Tarbela (Wapda, 2004) WAPDA Operation Rule

Tarbela reservoir should be lowered to reservoir elevation (El.) 1300 feet by 20 May of each year.

The reservoir should be held at El. 1300 feet until 20 June unless inflows exceed low level outlet capacity and after that allowed to fill El.1505 feet.

Above El.1505 feet, the reservoir should be filled at a rate of 1 foot per day in so far as permitted by inflows and irrigation demands. Minimum maximum rule curve is

shown in Figure 4.8.

Drawdown of the reservoir should be in accordance with the irrigation demands balanced against the amount of water available from inflows plus storage.


1250.0

1300.0

1350.0

1400.0

1450.0

1500.0

1550.0

1600.0

Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug

MONTHS

ELEV

ATI

ON

(Ft)

Figure 4.8 Minimum maximum rule curve at Tarbela (WAPDA, 2004) Reservoir Levels

The minimum reservoir level is 1300 feet. This level will assure the required minimum net head of 179 feet on the turbines with a margin of safety open and the

tailwater level is at El. 1115 feet or lower.

The maximum operating reservoir level is El. 1550 feet (normal full pool level). The maximum water level for spillway design flood is El. 1552.2 feet which allow

adequate free board.

After satisfying irrigation requirement, the reservoir may be kept as high as possible to maximize power production.

The rate of filling should not exceed 10 feet per day. The allowable rate of rise should be determined according to operation experience.

The normal releases for irrigation should be made through the turbines whenever possible so that power can be generated. Each turbine can produce 175,000 KW (or

239,000 Horse-power) when the wicket gates are 95% open and the net head on the


turbine is 378 feet. Under these conditions discharge from each turbine is 6,450 cfs

making a total of 25,000 cfs for the four.

The irrigation tunnel will be used when the irrigation demand is higher than the turbine discharge.

The irrigation tunnels should not be used with water level above El1505 when the spillway provides sufficient release. Minimum discharge is 50000 cfs for the service

spillway and 70,000 cfs for the auxiliary spillway.

The sill level of irrigation tunnel is El.1160, 65 lower than the power intakes. Thus until the delta encompasses the intakes, most of the heavier suspended sediment

would go through this tunnel and not through the power waterways.

Rapid variations in the downstream flow should be avoided. Every year the reservoir should be drawn down to El.1300, (minimum pool level) to

effect sediment flushing.

Previous Benefits from the Reservoir The project has been instrumental in achieving self-sufficiency in food through timely water

releases for irrigation. Billions of units of electrical energy generated at Tarbela dam saved

the country's foreign exchange required otherwise for thermal power generation. The total

project cost was Rs.18.5 billion. During the past 18 years of its operation, the dam

contributed over 68.332 billion in terms of direct benefits from water releases and power

generation. The total cost has been repaid three times and over.

Benefits from Water From 1975 to 1993 about 154.65 MAF of water has been released from the dam for the

development. The benefits obtained from these releases was Rs.31,561 million. About 6.31

MAF of water was released from the storage during 1992-93 which is worth Rs.1893 million

calculated at a rate of Rs.300 per acre feet.

Benefits from Power From 1975 to 1993 about 122,570 MKWH of energy was produced from the dam and the

benefits obtained from this Rs. 36,766 million. About 13,955 MKWH of energy was

produced during 1992-93 which is amount to Rs. 4,186 million calculated at a rate of Rs.0.30


per KWH. Water and power benefits from the 18 years of dam operation are listed in Table

4.6

Flood Mitigation Benefits Additional benefits were achieved from the project with incidental flood control. Most of the

floods occur during the summer monsoon season. The flood discharge is composed of

snowmelt flood (base flow) plus storm flood. It has been estimated 1,773,000 cfs (a constant

snowmelt flood, 6000 cfs + PMF, 1,173,000 cfs). Assuming discharge through the turbines

and one irrigation tunnel, the probable maximum flood, when routed through the reservoir,

showed surcharge of 2 feet above full reservoir level of 1550 feet AMSL. The maximum

discharge over the spillway is 1,495,000 cfs. The maximum and minimum design curves

ensure to take care of incidental floods.

On the basis of flood predictions, the reservoir can be lowered to a pre-determined elevation

considerably below the normal pool level. Drawdown to El.1505 for example, would provide

storage of about 2.4 MAF of flood water, equivalent to a flow of 400,000 cfs for a period of 3

days. Since immediate refilling is assured, this lowering of reservoir water level would not

result in loss of water to irrigation and power.


Table 4.6 Water and Power benefits from Tarbela dam (WAPDA, 1993, 2001, 2004)

Water Power Year Storage Release Benefits Generation Benefits

Total Benefits

(July-June) (MAF) (Rs.million) (MKWH) (Rs.million) (Rs.million)

1975-76 3.33 666 -- -- 666 1976-77 9.07 1814 138 42 1856 1977-78 10 2000 3367 1010 3010 1978-79 8.71 1742 3726 1118 2860 1979-80 9.91 1982 4123 1237 3219 1980-81 10.63 2126 4129 1239 3365 1981-82 11.33 2266 4200 1260 3526 1982-83 9.12 1824 5228 1569 3393 1983-84 9.18 1836 7451 2235 4071 1984-85 9.24 1848 7254 2176 4024 1985-86 9.76 1952 7994 2398 4350 1986-87 9.98 1996 8121 2436 4432 1987-88 7.52 1504 9403 2821 4325 1988-89 11.12 2224 10378 3114 5338 1989-90 7.32 1464 9982 2995 4459 1990-91 6.19 1238 11356 3407 4645 1991-92 5.93 1186 11765 3530 4716 1992-93 6.31 1893 13955 4187 6080 1993-94 9.41 2823 12956 3887 6710 1994-95 5.39 1617 14765 4430 6047 1995-96 8.17 2451 14822 4447 6898 1996-97 9.15 8235 14230 4269 12504 1997-98 8.06 7254 15084 4525 11779 1998-99 9.04 8136 16377 4913 13049 1999-00 8.708 7837 14747 4424 12261 2000-01 8.689 7820 12811 3843 11663 2001-02 8.3 7470 14390 4317 11787 2002-03 9.1 8190 15110 4533 12723 2003-05 8.7 7830 13400 4020 11850

Total 247.4 101224 281261 84379 185603


Figure 4.9 Tarbela Dam from space (Wikipedia, The free encyclopedia 2009)


4.3.2 Mangla Dam Mangla dam on river Jhelum which is a 12th largest earthfill dam in the world has been

completed in 1967. Jhelum river at Mangla has a catchment area of about 12,870 sq. miles.

Dam height is 380 feet. The original gross storage capacity of the reservoir was 5.35 MAF in

1967. Live storage capacity was 4.81 MAF which was about 90 percent of gross capacity

whereas dead storage capacity was 0.54 MAF. Capacity of main spillway is 1,100,000 cusecs

while of emergency spillway is 2,300,000 cusecs. The lake area of reservoir at maximum

pool level (1202 feet. above sea level) is estimated to be 100 sq. miles. Reservoir of Mangla

dam is shown in Figure 4.10. The main objectives of the dam are (i) water storage for

supplementing irrigation supplies (ii) hydropower Generation (WAPDA, 1989). Before

1991 hydropower capacity of Mangla dam was 800 MW with 8 units. In 1991, hydropower

capacity of the dam was increased to 1000 MW with 10 units. Figure 4.11 shows power

house and Bong canal at Mangla dam.

The primary objectives from the reservoir are assured water releases for agriculture and

hydropower generation therefore, no space is particularly reserved for flood control.

However storage between reservoir levels 1202 feet and 1228 feet (1.5 MAF) is reserved to

achieve incidental flood benefits. Recreation and fish production are additional benefits from

the reservoir.

Reservoir capacity is depleted due to sediment inflows which were averaged 73 MST

(million short ton) per year from 1967 to 2002 (WAPDA and MJV, 2003). Elevation capacity

curves showing depletion in storage due to sediments are shown in Figure 4.12.


Reservoir

Mangla Fort

Embankment

Figure 4.10 Mangla reservoir at 1040 ft AMSL (Photo taken on 22-Nov-2005)

Figure 4.11 Mangla dam power house and Bong canal (Photo taken on 08-May-2008)


Elevation Capacity CurvesMangla Dam Before Raising

900

950

1000

1050

1100

1150

1200

1250

0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0

Reservoir Gross Capacity (MAF)

Res

ervo

ir El

evat

ion

(feet

AM

SL)

196719831988199319972000

Figure 4.12 Elevation-capacity curves for Mangla (WAPDA and MJV, 2003) WAPDA Operation Rule

Mangla reservoir should be lowered to reserevoir elevation (El.) 1050 feet by 10 May of each year.

The reservoir should be held at El.1050 to El 1040 feet until 31 March unless inflows exceed low level outlet capacity and after that allowed to fill El.1202 feet.

Mangla reservoir should be filled upto its maximum conservation level 1202 feet before 1 September if permitted by inflows and irrigation demands. Minimum

maximum rule curve is shown in Figure 4.13.

Drawdown of the reservoir should be in accordance with the irrigation demands balanced against the amount of water available from inflows plus storage.


1030

1050

1070

1090

1110

1130

1150

1170

1190

1210

1230

Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug

Elev

atio

n (fe

et A

MSL

Minmum rule curve

Maximum rule curve

Figure 4.13 Minimum maximum rule curves at Mangla (Wapda, 2004) Previous Benefits from the Reservoir Benefits from Water The Mangla reservoir has been impounded in 1967. According to an estimate on water

releases for agriculture, industrial or domestic use from the reservoir, total benefits have

been computed about Rs.24,179 million from 1967 to 1993 (WAPDA 1993). Therefore,

average annual benefits from water, estimated from 26 year operation (1967-1993) comes

to be about Rs.930 million whereas the benefits during (1991-92) and (1992-93) have

been estimated to be Rs.936 million and Rs.969 million respectively. These estimates, as

reported, were carried out on the basis of a unit return of Rs.200.00 per acre foot volume of

water.

Benefits from Power WAPDA reported (1993) that total power generated from Mangla Dam between period 1967

and 1993 was 103,076 MKWH which gave a return of Rs.30,922.89 million to the country.

An average annual power generation from the project is 3964 MKWH. During 1992-93

power generated was 5780.09 MKWH, while during 1991-92 it was 5944.04 MKWH.

Mangla power station during 1988-89 has been able to touch maximum generation of 950

MW which is about 18.75 percent more than its installed capacity of 800 MW during that


period. Average annual returns from Mangla dam has been estimated about Rs.1189 million.

The returns/benefits during year (1992-93) due to power generation have been reported to be

Rs.1734.03 million whereas during year 1991-92 the benefits were Rs.1783.2. The highest

benefits during the entire operation period in the dam history was in 1987-88 when the

power generation was reported to be 6039.65 and its benefit was Rs. 1811.9 Million. All

these returns/benefits estimated here in monetary units were computed at the rate of Rs.0.30

per unit (WAPDA, 1993). Water and power benefits from the 26 years of dam operation are

listed in Table 4.7.

Table 4.7 Water and Power benefits from Mangla dam (WAPDA, 1993, 2001, 2004)

Water Power Year Storage Release Benefits Generation Benefits

Total Benefits

(July-June) (MAF) (Rs.million) (MKWH) (Rs.million) (Rs.million)

1967-80 58.32 17046.3 37150.5 13371.0 30417.3 1980-81 4.15 1458.8 3877.6 1535.0 2993.8 1981-82 5.30 1881.5 4090.3 1625.0 3506.5 1982-83 4.82 2210.8 4917.0 2523.7 4734.5 1983-84 5.35 2587.8 4162.5 2252.7 4840.5 1984-85 5.39 2961.6 3883.6 2388.3 5349.9 1985-86 4.56 2821.8 4637.6 3211.0 6032.8 1986-87 4.84 3083.4 5937.2 4232.0 7315.4 1987-88 4.88 3220.5 6039.7 4459.0 7679.5 1988-89 4.97 3821.8 5307.3 4556.0 8377.8 1989-90 5.03 3952.5 5621.3 4992.0 8944.5 1990-91 3.76 3343.0 5738.2 5708.0 9051.0 1991-92 4.68 4232.9 5944.0 6015.0 10247.9 1992-93 3.23 3490.7 5780.1 6989.0 10479.7 1993-94 5.37 5939.8 5022.5 6215.0 12154.8 1994-95 5.10 6282.9 6809.7 9386.0 15668.9 1995-96 3.94 5684.9 6977.3 11254.0 16938.9 1996-97 4.98 7888.7 5665.3 10041.0 17929.7 1997-98 4.36 7805.9 6103.7 12225.8 20031.7 1998-99 5.10 6462.7 4778.5 9920.0 16382.7 1999-00 4.21 8774.6 3184.7 7425.0 16199.6 2000-01 4.13 9523.3 2799.9 7223.0 16746.3 Total 156.47 24179.0 103076.3 30922.9 55101.9


Flood Mitigation Benefits Incidental flood control is an additional benefit which was achieved from the project. Most of

the floods occur during the summer monsoon season. Their duration is short but their rate of

rise and fall can be extremely rapid. The maximum and minimum design curves (Figure

4.13) ensures to take care of incidental floods. Available storage (1.5 MAF) between

reservoir level 1202 feet and 1228 feet is reserved to achieve incidental flood benefits. The

project was designed on a Probable Maximum Flood (PMF) of 2,600,000 cusecs. Total

benefits from water and power activities from Mangla dam comes to Rs.55,101.89 million

since 1967 whereas total benefits in financial years 1991-92 and 1992-93 from water and

power has been estimated to be Rs.2719.21and Rs.2703.03 million respectively.

Although these benefits are quite high, recovering the total cost of the project several times

over, but it is however, a limited source. The country has been facing the major problem of

rapidly increasing population and food requirements. These problems seriously affected the

existing policies and it is essentially needed to design a policy which may overcome these

issues by expanding irrigated agriculture and increasing power generation.

Mangla Raising Project At the time of construction of Mangla Dam, Government of Pakistan, requested the World

Bank that a provision should be made in the design and construction of the Mangla Dam to

facilitate its raising at a later stage by another 30-40 ft. The Government of Pakistan agreed

that the incremental cost of the provision for raising would not be charged to the Indus Basin

Development Fund. The World Bank accepted this proposal and hence, all the impounding

structures of the Mangla Dam Project were designed and constructed in 1967 for raising it by

another 30 ft. In year 2003, work on Mangla raising was started. It was proposed to raise the

Mangla dam by 30 feet. (WAPDA and Mangla Joint Venture, 2003). This will raise the

present maximum reservoir conservation level of 1202 ft to 1242 ft. The work on Mangla

raising is in progress as shown in Figure 4.14. About 70% construction work has been

completed on Mangla raising till May 2008. The project is expected to be completed in year

2009. This would increase the average annual water availability by 2.9 MAF. Power

generation from the existing power plant would also increase by about 11%. Elevation

capacity curves after Mangla raising showing depletion in storage due to sediments for the

period 2007 to 2082 are shown in Figure 4.15 (WAPDA and MJV 2003).


Figure 4.14 Work in progress on Mangla Raising (Photo taken on 22-Nov-2005)

Elevation Capacity CurvesMangla Dam After Raising

900

950

1000

1050

1100

1150

1200

1250

1300

0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0

Reservoir Gross Capacity (MAF)

Res

ervo

ir El

evat

ion

(feet

AM

SL

2007-082011-121016-172021-222026-272031-322036-372041-422046-472081-82

Figure 4.15 Elevation-capacity curves for Mangla Raising (WAPDA and MJV, 2003)


4.3.3 Chasma Reservoir

Located on the Indus River downstream of Tarbela dam, this reservoir acts as a buffer

reservoir to re-regulate the releases from Tarbela. It was constructed in 1971 as barrage cum

reservoir providing diversion facilities for Chasma Jhelum link Canal on its left side and

Chasma right bank canal on the right side. The reservoir acts as a re-regulatory storage for

the releases from Tarbela which enable the reservoir to store 2.59 MAF of water and releases

2.52 MAF during 1992-93. According to 1986-87 hydrographic survey by WAPDA, the

gross storage capacity of Chasma reservoir has been reduced from 0.87 MAF (originally in

1971) to 0.497 MAF.

Upto 1993, about 100.44 MAF of irrigation water was received in the reservoir. About 94.97

MAF was released downstream of Chasma barrage and 3.794 MAF in Chasma Jhelum Link

Canal (CJ Link) and 1.607 MAF in Chasma right bank canal (CRBC) The benefits obtained

from the reservoir are listed in Table 4.8

Table 4.8 Water benefits from Chasma Reservoir __________________________________ Year Storage (July-June) Release Benefits (MAF) (Rs. million) __________________________________ Upto 1980-81 8.41 1682 1981-82 0.74 148 1982-83 0.70 140 1983-84 0.49 98 1984-85 0.49 98 1985-86 0.49 98 1986-87 0.49 98 1987-88 0.49 98 1988-89 0.45 90 1989-90 0.28 56 1990-91 0.46 92 1991-92 2.70 540 1992-93 2.52 756 __________________________________ Total 18.71 3994 __________________________________


4.3.4 Loss of Reservoir Capacities

One of the important factors for future water scarcity in Pakistan is due to loss of existing

reservoir capacities by sediment inflows. It is a natural process and every reservoir has its

useful life. The solution is to make new dams to overcome water crisis. Hydrographic

surveys were carried out time to time by WAPDA to determine the loss of reservoir

capacities. Following table shows the depletion in gross capacities in Tarbela, Mangla and

Chasma.

Table 4.9 Loss of reservoir capacities in MAF (WAPDA, 2004)

Gross Storage Capacity Gross Storage Loss Reservoir Original Year 2004 Year 2004 2012 2025 Tarbela 11.62 8.36 3.26 4.17 5.51 (1974) 72% -28% -36% -47% Mangla 5.88 4.64 1.24 1.72 1.97 (1967) 78% -22% -29% -34% Chashma 0.87 0.48 0.39 0.48 0.5 (1971) 55% -45% -55% -57% Total 18.37 13.48 4.89 6.37 7.98 (73%) -27% -35% -43%

4.3 Hydrological and Other Data

Data used for this study was collected from Water and Power Development Authority

(WAPDA), Indus River System Authority (IRSA), Irrigation Department, Punjab and field

visits at damsites. The data collected from WAPDA includes inflows of Indus and its

tributaries, outflows from the reservoirs, rainfall data and pan evaporation data from the

climatological stations. The data also includes the basic information about the physical, legal,

social and economical features of the reservoirs and the hydropower generation from the

dams. The data collected from Irrigation Department, Punjab are the downstream water

requirements from the reservoirs and the historic canal withdrawals.


4.4 Barrages in the System There are 16 barrages located in the water resource system. These barrages receive water

from the upstream reservoirs or from the run of the river and diverts into the canals as per

requirement.

4.5.1 Chashma Barrage Location: Near village Chashma about 35 miles downstream of Jinnah Barrage on the Indus.

Purpose: 1. To divert water released from Tarbela dam into Jhelum river through

Chashma Jhelum link canal (CRBC, maximum capacity = 21700 cfs).

2. To feed Paharpur canal (maximum capacity = 500 cfs) taking of from the

right side.

Salient Feature: River valley is 6.5 feet wide, Barrage is 3536 feet long with 3120 feet of

clear water way to pass a maximum discharge of 950,000 cfs. The pond

with water level of R.L. 649 extends 14 miles upstream. This is for storage

of water in Chashma reservoir. The normal pond level is R.L. 642.

4.5.2 Rasul Barrage Location: In left side of Khadir, about 45 miles downstream of Mangla dam on the Jhelum

river.

Purpose: 1. To divert water released from Mangla dam into Chenab river through RQ

link canal (RQ Link, maximum capacity = 19000 cfs).

2. To feed Lower Jhelum canal feeder (maximum capacity = 5300 cfs) taking

of from the left side.

3. This supplements the discharge of water coming from upper Jhelum Canal

through the power canal of Rasul Hydro-electric power station.

4. Provision has been made in the right abutment for a proposed right bank

Jalalpur Canal.

Salient Feature: Barrage is 3209 feet long with 2800 feet of clear water way to pass a

maximum discharge of 850,000 cfs.

4.5.3 Qadirabad Barrage Location: About 20 miles below Khanki Head Works on Chenab river.


Purpose: 1. To receive water from Rasul Qadirabad link canal (RQ Link, maximum

capacity = 19000 cfs) and to divert Qadirabad Balloki canal (capacity

18,600 cfs).


maximum discharge of 900,000 cfs 45 bays with 5 bays as undersluices.

4.5.4 Marala Barrage Location: Confluence of Chenab and Tawi on the Chenab river constructed in 1910-12.

Purpose: 1. To supply water to Upper Chenab Canal (UCC, maximum and to divert

Qadirabad Balloki canal (capacity 18,600 cfs).

2. A feeder canal supplying water to Balloki headworks.

3. To feed Marala Ravir Link Canal (MR Link, capacity 22,000 cfs).

Salient Feature: Barrage is 4472 feet long to pass a maximum discharge of 1,100,000 cfs

66 bays with 10 bays as undersluices.

4.5.5 Sidhnai Barrage Location : Located on Ravi river, it was constructed in 1886.

Purpose : 1. To supply water Sidhnai feeder canal (4,005 cfs).

2. To feed Sidhnai Mailsi link canal (10,100 cfs).


maximum discharge of 150,000 cfs 14 bays with 5 bays as undersluices.

4.5.6 Mailsi Syphon Sidhnai Mailsi link was to supply Mailsi-Bahawal Link Canal. It was decided to transfer the

waters of Sidhnai Mailsi Link through a syphon built under River Sutlej about 25 miles

downstream of Islam barrage. The syphon was constructed in 1964. The length of the syphon

is 2231 feet.

4.5.7 Trimmu Barrage Location: Confluence of Jhelum and Chenab constructed in 1939.

Purpose: 1. To supply water to Trimmu Sidhnai Link (TS Link, maximum capacity

11,000 cfs) and to feed Haveli Canal in the left bank.

2. To feed Rangpur Canal in the right bank (maximum capacity 2700 cfs).

Salient Feature: Barrage is 3026 feet long to pass a maximum discharge of 645,000 cfs.


4.5.8 Balloki Headworks Location: Located on Ravi river. It was constructed in 1965

Purpose: 1. To supply water from QB link to BS Link.

2. To feed Lower Bari Doab canal (maximum capacity 7000 cfs).

Salient Feature: Barrage is 1647 feet long to pass a maximum discharge of 225,000 cfs.

4.6 Canals in the System There are 43 canals which supply water for agriculture in different command areas in the

water resource system. These canals receive water from the reservoirs / barrages and divert

either into the small distributaries as per requirement. There are two zones of water source

for these canals.

1. Indus Zone 2. Jhelum Chenab Zone

Indus zone consists of Tarbela command canals. These are 28 canals in this zone. Jhelum Chenab zone comprised Mangla command canals. There are 16 canals in this zone. The capacity of these canals and their names are presented in Table 4.11. Location of major canals is shown in Figure 4.16. 4.7 River Gains and Losses There is always some gains or losses between the head and tail of river and canal reaches in

the Indus Basin. The losses usually occur during the rising stage in period April to June and

flood months of July and August. The gains usually occur from September to March. Both

the gains and losses in Indus Basin is a complex phenomena. Various studies are carried out

and seasonal historic gains are losses are computed by WAPDA for the period 1940-86. The

average of gains and losses for the period are given in Table 4.12. Year wise estimated gains

and losses are shown in Figure 4.17. (Wapda Loose Files)


Table 4.10 Summary of the basic Information of the Barrages located in the Indus Basin

Width Between

Abutments

Designed Maximum Discharge

Crest Level

Sr. No.

River

Name of

Barrage

Year of

Completion (feet) (cusecs)

Offtaking Canals

(feet)

Indus 1 Kalabagh 1946 3797 950,000 678 Thal 2 Chashma 1971 3556 1,100,000 622 CJ, CRBC, DG Khan 3 Taunsa 1959 4346 750,000 428 Muzafarghar TP Link

4 Guddu 1962 4445 100,000 236 Pat Feeder, Desert Beghari, Ghotki

5 Sukkur 1932 4725 1,500,000 177 NW, Rice, Dadu Rohri, Nara, Khanpur East, Khanpur West

5 Kotri 1954 3034 875,000 48 Kalri, Pinyari Fuleli, Lined Jhelum

5 Rasul 1901 4400 875,000 708 Lower Jhelum 1967 3209 850,000 703 RQ Link

7 Trimmu 1939 3026 645,000 477 TS Link, Rangpur 8 Punjnad 1932 3400 700,000 325 Panjnad, Abbasia Chenab

9 Marala 1912 4475 718,000 800 MR Link 1968 4475 1,100,000 800 Upper Chenab

10 Khanki 1891 4414 750,000 721 Lower Chenab 11 Qadirabad 1967 3373 900,000 684.5 QB Link

LCC Feeder Ravi Ravi Syphon Central Bari Boab Upper Depalpur

12 Balloki 1913 1647 139,500 622.4 BS-I, BS-II 1965 1647 225,000 624.5 Lower Bari Doab Lower Depalpur

13 Sidhnai 1965 712 167,000 454 Sidhnai, Haveli Sutlej

14 Sulemanki 1926 2223 325,000 560 Upper Pakpattan Fordwah, Sadiqia

15 Islam 1927 1621 275,000 441 U.Mailsi, Qaimpur U.Bahawal

16 Mailsi 1965 1601 429,000 415.5 L.Pakpattan, L Mailsi Syphon L.Bahawal


Table 4.11 Indus zone and Jhelum Chenab Zone


Figure 4.16 Location of major canals in Indus Basin Irrigation System (WAPDA, 1988)


Table 4.12 Average Gains and Losses (MAF) of 46 Years of data _________________________________________________________ Reach Kharif Rabi Total ________________________________________________________ 1. JC Zone Mangla-Rasul 1.578 0.413 1.991 Rasul-Trimmu -0.033 0.500 0.467 Trimmu-Panjnad -1.510 0.332 -1.178 Marala-Khanki 0.398 0.020 0.418 Khanki-Trimmu 0.228 0.775 1.003 Balloki-Sidhnai -0.071 0.189 0.118 Total 0.590 2.229 2.819 2. Indus Zone Attock-Kalabagh -2.401 -0.405 -2.806 Kalabagh-Taunsa -0.183 0.840 0.657 Taunsa-Guddu 2.178 0.186 2.364 Guddu-Sukkur -0.379 0.186 -0.193 Sukkur-Kotri -7.417 0.687 -6.730 Total -8.202 1.494 -6.730 _________________________________________________________

Historic Gains and Losses In Indus Irrigation System1941-2003

-40.0

-35.0

-30.0

-25.0

-20.0

-15.0

-10.0

-5.0

0.0

5.0

10.0

15.0

1940

-41

1943

-44

1946

-47

1949

-50

1952

-53

1955

-56

1958

-59

1961

-62

1964

-65

1967

-68

1970

-71

1973

-74

1976

-77

1979

-80

1982

-83

1985

-86

1988

-89

1991

-92

1994

-95

1997

-98

2000

-01

Gai

ns (+

) and

Los

ses (

-) (M

AF)

.

Post Tarbela Period

Post Mangla Period

Figure 4.17 Year wise historic gains and losses from the Indus Irrigation System

4.8 Complete river basin multi reservoir system The Indus River System comprises of 3 storage reservoirs (Tarbela, Mangla and Chasma), 16

barrages, 12 inter-river link canals, 2 major syphons and 43 canals. It is the largest integrated


irrigation network in the world. The complete system is represented by nodes and arcs. In

each time step there are 67 nodes and 119 arcs. The complete river basin multi-reservoir

system of Indus Basin is taken in this study and it is shown schematically in Figure 4.16.

The unregulated flows in the selected system are from the seven rivers namely Indus, Jhelum,

Chenab, Kabul, Gomal, Ravi, Sutlaj. Three existing reservoirs are located in the system

namely

Mangla on Jhelum [Irrigation flows + power generation] Tarbela on Indus [Irrigation flows + power generation] Chashma on Indus [Irrigation flows only]

The flows are regulated from these reservoirs and diverted to the canals. In addition there are

16 barrages, located on different locations of the river reaches to divert water to different

irrigation canals. These barrages receive water from two zones. One is called Indus zone and

other is called Jhelum Chenab zone. In the Indus zone, there are 7 barrages with 23 major

irrigation canals of different capacities. In Jhelum Chenab zone there are 7 barrages and 2

syphons diverting water to 23 number of major irrigation canals.

Indus Zone Jinnah Thal Taunsa Dera Ghazi Khan, Muzaffar Ghar, TP Link Guddu Pat Feeder, Desert, Beghari, Ghotki sukkur Nara, Khanpur E & W, Rohri, Dadu, Rice, NW Kotri Lined, Fuleli, Pinyari, Kalri (Ghulam Muhammad) Trimmu Rangpur, TS Link Punjnad Panjnad, Abbasia Jhelum Chenab Zone Rasul Lower Jhelum, RQ Link Marala MR Link, BRBD, UC Link, Khanki LC Qadirabad QB Link, LCC Feeder Ravi Syphon U.Depalpur, Central Bari Doab Balloki Lower Bari Boad, BS I & II, L Dipalpur Sulemanki U.Pakpattan, Fordwah, East Sadiqia Islam U.Mailsi, Qaimpur, U.Bahwal Mailsi Syphon L.Pakpattan, L Mailsi, L.Bahawal

The remaining water passing through Kotri(Ghulam Muhammad) Barrage is drained into the

Arabian sea and the Indus River System is completed.


This Page is Kept Blank for

Figure 4.18 Node Arc Representation and Schematic Diagram

See File name NFINDUS-v3

462s-4

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