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WATER MANAGEMENT IN BALUCHISTAN - Muhammad Ramzan Chaudhry

Muhammad Ramzan Chaudhry
Director, International Waterlogging and Salinity Research Institute
Lahore, Pakistan

EXECUTIVE SUMMARY

Baluchistan lies in the desert belt between 25° N and 32° N. It has an arid to semi-arid climate, and water resources are limited compared to other provinces of Pakistan. The main sources of water on which people depend are springs, streams, rivers and karezes. In most of the area, karezes were persistent and sufficient water was available to meet requirements. But with the widespread introduction of tubewell technology, many karezes dried because of overexploitation. Tubewells helped to increase cropping intensities and yields, but overexploitation led to mining of groundwater, especially near large cities. Baluchistan's annual surface water allocation by the National Water Accord is about 5 billion m3, which is not sufficient to meet crop water requirements; groundwater is being used to augment it. Uncontrolled installation of numerous public and private tubewells has resulted in groundwater mining.

Rainfall is scanty and unevenly distributed. About 50 percent of the area is irrigated through sailaba (flooding) and khushkaba (water harvesting), the other 50 percent through canals, karezes, springs and tubewells. Monitoring has revealed a fall in groundwater levels in many areas, indicating groundwater mining. Investigations have shown that there are some groundwater resources that can be exploited, because the water varies from good to marginal and can be used for irrigation.

Groundwater-management problems include poor governance and lack of commitment from the public and private sectors. Development and management of groundwater can be improved by controlling overexploitation, introducing legislation and strengthening institutions. Measures have been taken to recharge groundwater, including delayed-action dams, development of ponds, dikes and check dams and rehabilitation of karezes; these need further improvements. Watershed management can play a significant role in improving water resources.

A groundwater development and conservation authority should be established to improve water management, groundwater investigations should be given priority, groundwater mining should be controlled and recharge techniques and efficient technologies such as sprinkler/drip systems should be introduced. There is a need for more research. An integrated surface and groundwater management programme should be introduced.

INTRODUCTION

Agriculture, which is largely dependent on irrigation, plays a pivotal role in Pakistan's economy. Baluchistan is the largest province in terms of area, but has the smallest number of people per unit area. It is situated in the desert belt, between 250 N and 320 N. The climate is arid to semi-arid with low rainfall, dry winds, cold winters and hot summers. Irrigation is essential to agriculture in most of the province, but water resources are limited and uncertain compared to the other provinces.

The water resources in the province have been used for centuries, but they are not sufficient to meet crop water requirements, which hampers development of land resources. Of an area of 34.7 million ha, about 18.5 million ha are reported as used, of which 1.7 million ha are cultivated.

The people of Baluchistan have always depended on natural water sources such as springs, streams, rivers and karezes. Among these, the karezes are the most persistent; other sources are seasonal and depend on climatic conditions.

With the passage of time, water resources are being overexploited, especially in urban areas, and groundwater levels are sinking. If this process continues, there is a danger that water may not be available even for human consumption. The population and provincial authorities must pay immediate and special attention to careful and efficient use of available resources. The objective is to assess Baluchistan's water resources and their management.

CLIMATE

Extreme temperature variations have been observed: at Quetta, a temperature of -12°C has been recorded in winter, and at Sibi, the hottest place in Pakistan, a temperature of 51°C has been recorded in summer. Precipitation over a large part of the province is about 100 mm per year. Mean annual evaporation rates vary from 3 000 to 5 000 mm. Isohyetal contours identify three distinct regions; contours drawn on the basis of data from 1910 to 1950 show higher rainfall compared to 1960 to 1985 in all three regions, which may indicate a change in regional weather patterns.

LAND UTILIZATION IN BALUCHISTAN

Land utilization statistics are given in Table 1. It is clear that the area sown has increased considerably with the passage of time. To irrigate this additional area and increase production, more water resources are needed.

Table 1. Land-utilization statistics: Baluchistan; areas in millions of ha

Year

Area reported

Forest

Not available for cultivation

Cultivable waste

Cultivated area

Current fallow

Net area sown

Area sown more than once

Total cropped area

1983-84

19.09

1.09

11.16

5.39

1.45

0.79

0.66

0.02

0.68

1989-90

18.60

1.09

11.16

4.74

1.61

0.91

0.80

*

0.70

1995-96

18.60

1.09

11.16

4.66

1.69

0.65

1.04

*

1.04

1998-99

19.37

1.05

11.34

4.87

2.11

1.14

0.97

*

0.97

Source: Government of Pakistan (2000)

Rainfall is irregular and scanty with wide seasonal variations, a common feature of desert regions. The plains and lower highlands receive monsoon rainfall during July and August; the upper highlands receive rainfall from storms arriving from the Persian plateau in February and March.

Figure 1. Map showing rivers and streams in Baluchistan

WATER RESOURCES OF BALUCHISTAN

Water plays a significant role in the economy of the province. Development of the agricultural sector depends on secure supplies of good-quality water. There is an urgent need to use available water resources in the most efficient ways and to develop new resources to the maximum. The main water sources are detailed below.

Surface-water resources

An agreement for sharing water among four provinces was signed in March 1991; the provincial allocations are shown in Table 2.

Table 2. Provincial water allocation

Province

Water allocation (million m3)

Kharif

Rabi

Annual

Punjab

46 000

23 000

69 000

Sindh

42 000

18 000

60 000

NWFP

40 000

3 000

7 000

Baluchistan

4 000

1 000

5 000

Total

96 000

45 000

141 000

Precipitation is the main source of surface water. Baluchistan has numerous rivers and streams flowing from mountain ranges and highlands, shown in Figure 1. No major storage dam exists in the province to store water from flash floods, which may cover many km2.

Groundwater resources

Development of groundwater resources

Groundwater has always been and still is an important source of irrigation water in Baluchistan. It occurs in hard consolidated rock and unconsolidated alluvium rock. In hard rock, good aquifers exist in zones with many joints, fractures, fissures and caverns. Unconsolidated deposits with good aquifers are in gravel and sand. It is extracted from dug wells, tubewells and on a limited scale through the karez system. There has been a rapid increase in drilling over the last 20 years, resulting in some major benefits but with accompanying disadvantages. Until 1989, approximately 22 percent of land in the province was irrigated from underground water resources such as karezes, springs, open wells and tubewells. By 1998, however, land irrigated from these sources was 34.5 percent, with tubewells alone accounting for 22.8 percent. Domestic water requirements are largely met from groundwater (Khan and Mian, 2000).

The number of tubewells drilled by government agencies from 1950 to September 2000 is given in Table 3, which shows a significant increase in the installation of tubewells over time reflecting increased exploitation of groundwater for agricultural, industrial and urban consumption.

Table 3. Drilling of tubewells by government agencies

Period

I&P dept.

BDA

PHE dept.

WAPDA

Total

1950-1960

75

-

-

-

75

1961-1965

80

-

-

-

80

1966-1970

-

-

-

29

29

1971-1975

81

-

-

143

224

1976-1980

89

-

-

411

500

1981-1985

147

64

-

272

483

1986-1990

174

45

157

446

822

1991-1995

56

68

221

375

720

1996-1997

33

32

62

91

218

1997-2000

77

22

24

-

123

Total

812

231

464

1 767

3 274

I&P Dept. = Irrigation and Power Department, Government of Baluchistan
BDA = Baluchistan Development Authority
PHE Dept. = Public Health Engineering Department, Government of Baluchistan.
Sources: Bureau of Water Resources (1997); Khan and Mian (2000).

The impact of groundwater development on socio-economic conditions

With tubewell technology ensuring a sufficient supply of water, there was significant increase in the area under orchards. This caused a major shift from traditional low-value crops to high-value cash crops, resulting in a positive impact on the provincial economy. Tubewell development increased cropping intensities by 100 percent, but indiscriminate and unplanned use of groundwater resources with tubewells has resulted in overexploitation in several valleys, leading to a steady fall in aquifer water levels. Such unsustainable use of groundwater has affected karez flows; collapsing tunnels have made these unusable. According to a WAPDA report of June 1992, of 1 000 karezes 464 are in good running condition, 266 have declining flows and 270 have gone dry. Most karezes that are drying or have declining inflows are in the Quetta valley, where excessive withdrawals are made to meet water requirements of the area. This is a major problems for Quetta.

Excessive withdrawal has resulted in a shift of population from rural to urban areas, which strains urban resources. Quetta has to bear the brunt of this migration, which has serious social and economic repercussions and which has disturbed the homogeneity of rural society, creating social problems for the urban and rural populations.

Rainwater

Rainfall in the province varies between 50 and 350 mm per annum. The plains and lower highlands receive rainfall in summer monsoons and the upper highlands in winter. Annual and seasonal rainfall is shown in Table 4.

Table 4. Annual and seasonal rainfall in Baluchistan


Station

Altitude (m)

Rainfall (mm)

Winter
Nov-May

Summer
Jun-Oct

Annual

1

Babar Kach

243

58

92

150

2

Badinzai

1 521

115

212

327

3

Bit Buleda

608

72

47

120

4

Barkhan

1 095

105

218

324

5

Chaman

1 311

202

10

212

6

Chaghi

844

65

7

50

7

Dalbandin

877

78

7

85

8

Duki

1 083

121

110

230

9

Gwadar

145

85

15

100

10

Harnai

870

145

197

342

11

Kalat

2 012

154

40

194

12

Kila Abdullah

1 589

190

11

201

13

Khuzdar

1 241

95

97

192

14

Lesbela

89

90

134

224

15

Loralai

1 429

130

92

222

16

Mastung

1 682

170

19

189

17

Nushki

1 039

138

11

149

18

Ranjpur

966

85

40

125

19

Pasni

9

117

25

142

20

Quetta

1 670

193

29

222

21

Sibi

134

59

73

132

22

Turbat

155

120

25

145

23

Usta Mohammad

55

60

30

90

24

Ziarat

2 433

215

107

322

Source: WAPDA, (1993)

In the continental highland, winters are characterized by cold, snowy weather; summers are cool, with irregular monsoon rains. The continental plateaus are the hottest and driest regions of the province; heat, dust storms and aridity predominate. Variations in monthly/annual rainfall are given in Tables 5, 6 and 7, which reflect considerable variations in different months and different years. Rainfall is one of the dependable sources of irrigation for economical crop production, because rainwater can be stored in small dams and be used when required.

Table 5. Monthly rainfall data for Qila Ladgasht (mm)

Year

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

Total

1993

37.34

15.75

19.56

92.20

0

0

0

0

0

0

0

0

163.85

1994

0

0

0

0

0

0

0

5.33

0

0

0

6.35

11.61

1995

2.79

13.21

22.86

12.70

0

0

3.56

0

0

0

0

115.57

170.69

1996

8.38

16.76

15.24

0

8.64

14.48

3.56

0

8.64

0

1.78

0

80.02

1997

16.26

6.86

15.75

8.64

14.48

17.02

12.19

1.52

0

17.02

25.91

14.73

150.38

1998

2.68

2.15

3.84

1.04

0.80

1.75

0

0

1.12

0

0

0

13.30

1999

4.63

11.56

2.93

0

0

0

2.46

0

0

0

0

0

21.58

Sources: Annual reports: river and climatological data of Baluchistan, Bureau of Water Resources; Khan and Mian, 2000

Table 6. Monthly rainfall data for Mashkai (mm)

Year

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

Total

1993

3.81

0

0

0

0

0

0

7.62

0

0

0

0

11.43

1994

0

0

0

0

0

0

0

0

0

0

0

0

0

1995

0

0

0

0

0

0

0

0

0

0

0

0

0

1996

0

0

0

0

0

0

0

0

0

0

0

0

0

1997

0

0

0

0

0

0

0

0

0

0

0

0

0

1998

20.10

3.30

11.94

0

0

0

0

0

0

0

0

35.33

70.65

1999

1.78

13.72

1.02

0

0

0

0

0

0

0

0

16.51

33.03

Sources: Annual reports: river and climatological data of Baluchistan, Bureau of Water Resources; Khan and Mian, 2000.

Table 7. Monthly rainfall data for Shadi Kaur (mm)

Year

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

Total

1993

0

0

0

0

0

0

0

0

0

0

0

0

0

1994

0

0

0

0

0

0

0

0

0

0

0

2.03

2.03

1995

0

2.03

1.27

0

0

0

18.54

0

0

0

0

25.65

47.4

1996

0

0

0

0

0

0

0

0

0

0

0

0

0

1997

39.12

0

89.41

0

9.14

0

43.43

1.52

0

60.71

21.59

0

264.92

1998

4.32

19.81

6.35

0

0

0

0

0

0

0

0

0

30.48

1999

0

0

8.13

0

9.91

0

0

0

0

0

0

0

80.03

Sources: Annual reports: river and climatological data of Baluchistan, Bureau of Water Resources; Khan and Mian, 2000.

AREA IRRIGATED BY DIFFERENT SOURCES

Agriculture is the mainstay of the economy; about 77 percent of the population live in rural areas. The area irrigated from various sources is given in Table 8, which shows that about 50 percent of the area is sailaba and the other 50 percent irrigated by canals (29.3 percent), karezes and springs (5.93 percent), tubewells (13.94 percent) and wells (0.83 percent). Of the 347 190 km2 of the province, 149 467 km2 are classified as arid and 197 723 km2 as semi-arid (Khan and Mian, 2000). The increase in the irrigated area is presented in Table 9: in the 20 years during which the irrigated area has been growing, the major increase has resulted from the use of tubewells.

Table 8. Areas irrigated by different sources

Source

Area (ha)

%

Sailaba (flood) and khushkaba (water harvesting)

843 000

50.00

Canal irrigation

494 000

29.30

Karezes and springs

100 000

05.93

Tubewells

235 000

13.94

Wells

14 000

00.83

Total

1 686 000

100

Source: Agriculture statistics of Baluchistan, 1995-96.

Table 9. Increase in area irrigated by different sources in Baluchistan (million ha)

Year

Total

Canals

Tubewells

Wells

Canal tubewells

Canal wells

Tanks

Other

Govt.

Private

1980-81

0.53

0.34

0.04

0.05

0.02

0.02

-

-

0.08

1986-87

0.52

0.32

0.02

0.10

0.02

0.02

-

-

0.06

1992-93

0.74

0.41

0.08

0.20

0.01

-

-

-

0.10

1998-99

0.84

0.42

0.08

0.25

0.01

-

-

-

0.08

Source: Government of Pakistan (2000).

IMPACT OF GROUNDWATER DEVELOPMENT ON WATERTABLES

To evaluate the impact of groundwater development, monitoring of groundwater levels was started in 1988 at Quetta, Mastung, Mangochar and Pishin sub-basins of the Pishin Lora basin. The network was started with 222 monitoring points: 15 automatic water-level recorders, 12 piezometers and 195 open surface wells. These were reduced to 175 by December 1995 and 88 by August 2000 as open wells dried up or were converted to deep wells with pumps. Details of the monitoring are given in Table 10.

Monitoring has shown falls in groundwater levels in the Quetta, Pishin, Mastung and Mangochar valleys, indicating groundwater mining. This overexploitation calls for an immediate response by the Government of Baluchistan. The impact of three decades of mining is reflected in Table 11.

GROUNDWATER POTENTIALS

Results of the groundwater investigations carried out in Baluchistan by various organizations are given in Table 12. Groundwater resources are limited, so it is important that they are evaluated.

Table 10. Monitoring points: Pishin Lora basin

Sub-basin

Open surface wells

Piezometer

Automatic recorders

Total

Quetta North

Original

33

05

10

48

December 1996

13

02

09

24

Quetta South

Original

20

02

00

22

December 1996

08

01

00

09

Pishin

Original

48

01

00

49

December 1996

33

01

00

34

Mastung

Original

44

02

04

50

December 1996

16

00

04

20

Mangochar

Original

04

01

01

06

December 1995

00

00

01

01

Total

Original

149

11

15

175

December 1995

070

04

14

088

Source: Khan and Main, 2000.

GROUNDWATER BALANCE

In order to re-assess the groundwater potential of Pishin, Nari, Zhob, Porali, Hamun-e-Lora and Kachhi Plain basins, a study was sponsored by the Asian Development Bank and undertaken by A.D.B. Halcrow in 1996. It revealed that available groundwater in Pishin Lora, Nari and Zhob basins is limited and that groundwater mining is taking place from aquifer storage in Quetta, Mastung, Mangochar, Pishin, Loralai and Qila Saifullah sub-basins. Table 13 shows the water balance in these sub-basins.

Table 11. Monitoring results: Pishin Lora basin


Period

Decline in water level

Average (m)

Quetta North

1969-1989

4.58

1989-1996

4.27

1997-2000

4.39

Quetta South

1967-1988

2.44

1988-1996

1.83

1997-2000

2.44

Pishin

1976-1989

3.97

1989-1996

6.40

1997-2000

6.71

Mastung

1976-1989

6.40

1989-1996

2.78

1997-2000

4.27

Mangochar

1976-1990

15.25

1990-1996

28.89

1997-2000

6.10

Source: Khan and Mian, 2000.

GROUNDWATER QUALITY

The quality of water from karezes, springs, shallow and deep tubewells is given in Table 14 and Table 15. The pH range for all water is from 7.5 to 8.0. SAR is low, indicating that all water is suitable for irrigation. Values of Ca+++ Mg++ and the quantity of dissolved solids fall with groundwater depths. The quantity of sulphates in anions decreases, however. Table 14 and Table 15 show that use of this water will help to improve soil properties and lead to better crop yields.

Table 12. Groundwater resources in Baluchistan


Basin

Potential (cusec)

Depth (m)

Water quality (ppm)

1

Porali River

115

0.61-33.55

300-1 951

2

Dasht River

51

6.40-34.47

551-3 012

3

Hingol River

168

11.29-50.63

285-1 344

4

Gaj River

38

0.91-42.70

327-1 262

5

Mula River

26

1.83-56.12

384-1 036

6

Rakshan River

27

6.71-39.65

571-1 874

7

Hamun-e-Mashkhel

68

3.05-48.80

312-3 100

8

Hamun-e-Lora

28

6.71-23.49

704-1 020

9

Pishin Lora

145

4.27-100.65

265-1 927

10

Nari River

120

3.05-45.75

450-2 100

11

Zhob River

125

11.59-76.25

340-1 481

12

Kachhi Plain

95

2.44-250.40

660-14 100

13

Other areas

70




Total

1 116



Source: WAPDA (1994)

Changes in groundwater quality over time are minimal, except for a slight increase in calcium and magnesium concentrations that appear to increase in winter months. The high concentration of bicarbonates indicates that recharge occurs through the limestone in the north; the quantity is about the same in all the water samples. The concen-tration of sulphates appears to increase with Ca++ + Mg++. It may be noted that the quality of flood water is the best. Springs generally flow through solution channels and dissolve minerals from the rocks through which they pass. Concentra-tions of salts are therefore highest in spring. Shallow wells appear to intercept recharge from the limestone in the north. Karez water appears to be a mix of water recharged through fans and through adjacent rocks. Groundwater from deep tubewells appears to have been diluted from a recharge source other than the source for shallow wells and karezes.

Table 13. Groundwater balance in basins of Baluchistan

Basin

Sub-basin

Recharge (cusecs)

Extractions (cusecs)

Drawn out of storage (cusecs)

Pishin Lora

Quetta-North

38.4

67.2

28.8

Pishin-Lora

Mastung

21.8

31.7

9.8

Pishin-Lora

Mangochar

10.0

24.7

14.7

Pishin-Lora

Pishin

28.5

84.0

55.5

Nari

Loralai

63.2

74.8

11.6

Zhob

Qilla Saifullah - West

41.3

59.4

80.1

Source: A.D.B. Halcrow: Baluchistan groundwater assessment (1996).

Table 14. Water quality: various sources

Source

Salinity (ppm)

pH

Cations (me/l)

Total

Anions (me/l)

Total

SAR

RSC* (me/l)

Ca++ + Mg++

Na+

K+

CO3 -

HCO3

Cl

SO4

Karezes

512
(385-662)

7.8

7.1

2.14

0.07

9.31

0.17

4.62

1.46

3.04

9.29

1.14

-

Springs

491

8.2

14.7

2.15

0.07

16.92

0.80

3.70

1.25

11.17

16.92

0.79

-

Shallow wells

370
(415-2771)

7.7

9.63

4.60

0.075

14.31

0.16

4.64

2.36

7.16

14.32

1.92

-

Deep wells (WAPDA wells)

588

-

5.06

1.75

-

6.81

-

4.57

1.18

1.05

6.80

1.10

-

Flood water

116
(97-138)

7.4

2.9

0.18

0.25

3.33

-

2.49

0.51

0.29

3.29

0.14

-

* Residual sodium carbonate
Source: Government of Baluchistan (1986).

Table 15. Water quality of tubewells, karezes, spring and flood water in the project area

Location

Source

Samples

Salinity micro mhos/cm (%)

SAR (%)

0-700

700-1000

1000-1500

1500-3000

3000

0-3

3-6

6-9

Durgai

Tubewell

5

3(60)

2(40)

-

-

-

5(100)

-

-

Lori Daman

Tubewell

7

1(14)

2(30)

2(30)

1

1

4(100)

3(40)

-

Durgai

Karez

1

-

-

1(100)

-

-

1(100)

-

-

Zeriabad

Karez

1

1(100)

-

-

-

-

1(100)

-

-

Shabozai

Karez

1

-

1(100)

-

-

-

1(100)

-

-

Sharen

Karez

1

-

1(100)

-

-

-

1(100)

-

-

Tojgi

Spring

1

-

1(100)

-

-

-

1(100)

-

-

Durgai area

Flood

3

3(100)

-

-

-

-

1(100)

-

-

Durgai (Daman Manda)

Flood

1

1(100)

-

-

-

-

1(100)

-

-

Lori Daman (govt. scheme)

Flood

1

1(100)

-

-

-

-

1(100)

-

-

Sharen Hamzazai (govt. flood scheme)

Flood

1

1(100)

-

-

-

-

1(100)

-

-

Sharen Hamzazai (flood channel)

Flood

1

1(100)

-

-

-

-

1(100)

-

-

Source: Government of Baluchistan (2000).

MAJOR ISSUES IN GROUNDWATER RESOURCES MANAGEMENT

Poor management

The private sector has been more active in groundwater exploitation and development; public sector exploitation has been limited. Groundwater-resources management problems arise from poor governance and lack of commitment from the public and private sectors.

Political interference

On March 22 1978, the Government of Baluchistan promulgated the Baluchistan Ground Water Rights Administration Ordinance in order to manage and regulate the use of groundwater. Under this ordinance, a provincial water board and district water committees were established, but because of political interference, the tribal system and a failure of government agencies to enforce the measures, the desired results have not been achieved.

Lack of integrated approach

In spite of the government ordinance of 22 March 1978, there is no integrated approach to groundwater management. Groundwater mining is on the increase and the situation in some valleys, especially the Quetta valley, is getting more serious day by day. The drilling of tubewells has directly affected karez flows, with the result that most karezes are drying up.

DROUGHT CONDITIONS IN BALUCHISTAN

Rainfall has been below normal in 24 out of the 26 districts of Baluchistan in the last four years. Kharan, Chagai and Zhob districts have been the worst affected: famine conditions have caused the deaths of about seven million head of livestock and affected 1.3 million people (Khan and Mian, 2000). Dug wells are the main source of drinking-water for people and animals. The main economic activity is rearing livestock such as goats, sheep and camels; loss of vegetation for fodder during the drought resulted in the deaths of many animals.

To reduce the sufferings of the population, the Government of Baluchistan has adopted measures to supply drinking-water for people and animals through a scheme using windmills to abstract underground water. The wind in these areas is sufficient to operate the windmills and raise underground water from depths of 12 m to 30 m near settlements. The plan is to install 250 windmills in Kharan, Chagai, Zhob, along the coastal belt and around Quetta, all of which are badly affected by drought.

STRATEGIES TO IMPROVE GROUNDWATER DEVELOPMENT AND MANAGEMENT

Control of groundwater mining

In the second half of 1960, government policies were directed towards groundwater development, which was seen as the key to Baluchistan's agricultural prosperity. Wells were drilled and pumping equipment supplied at subsidized rates or against interest-free loans with subsidized energy rates. This encouraged over-pumping, the effects of which are visible in the form of declining watertables and groundwater mining. To replenish groundwater resources, so-called delay-action dams have been constructed in several valleys, but results are not encouraging because silting hinders percolation and prevents aquifers from delivering the desired results.

Legislation and institutional strengthening

One practical way to control groundwater mining is to strengthen the institutions that are to oversee implementation of the Groundwater Rights Administration Ordinance. Legislation and practical measures are needed to discourage the drilling of new tubewells and to regulate groundwater use on the basis of hydrological criteria and groundwater availability, keeping future needs in view. Modern techniques such as mathematical modelling to predict groundwater yield in future should be used, and a programme of public awareness through radio, TV and leaflets should be be introduced.

DRAINAGE WATER

Waterlogging and salinity are creating serious problems for the sustainability of irrigated agriculture in Pakistan; control of these problems is fundamental. The areas affected in Baluchistan are given in Table 16 and Table 17, which show that there is some increase in the area with watertables between 0-152 cm and 0-305 cm. This indicates that effective manage-ment is needed to maintain land and agricultural sustainability in the province.

Table 16. Extent of waterlogging and salinity: 0-305 cm watertable depth (ha × 1 000)

1993

1994

1995

1996

1997

1998

June

Oct.

June

Oct.

June

Oct.

June

Oct.

June

Oct.

June

Oct.

196

187

194

242

210

261

199

230

249

249

221

-

Source: Government of Pakistan (2000).

Table 17. Extent of waterlogging and salinity: 0-152 cm watertable depth (ha × 1 000)

1993

1994

1995

1996

1997

1998

June

Oct.

June

Oct.

June

Oct.

June

Oct.

June

Oct.

June

Oct.

85

117

72

147

87

138

46

138

154

120

92

-

Source: Government of Pakistan (2000)

Good to marginal-quality drainage water can be reused for irrigation, with consequent increases in crop production and some reduction of disposal requirements. The drainage system is, however, being misused by industries and urban authorities, which discharge untreated industrial effluent and city sewage into the drains. This must be stopped. The provincial drainage system is shown in Figure 2.

Figure 2. The drainage system in Baluchistan

Shortage of irrigation water means that farmers irrigate vegetables and crops with city sewage water. Such untreated water causes agricultural problems such as weed infestation and soil infertility and has residual effects on vegetables and fruit consumed by local populations. If this water is to be used for irrigation it must be treated.

WATERSHED PLANNING AND MANAGEMENT

Mechanical management

Water-conservation measures adopted by the Government of Baluchistan are briefly described below.

Biological conservation

Organic mulching

Organic materials such as animal manure, human excreta and plant residues act like a sponge, improving soil structure and increasing porosity, thereby allowing greater water percolation.

Management by planting suitable tree species

A major feature of watershed conservation is the planting of suitable trees in river, stream and reservoir catchments. This reduces runoff and the level of silt carried in flood flows. An additional benefit is that trees, shrubs, herbs and grasses improve groundwater recharge by increasing infiltration: roots open soils and penetrate layers of consolidated rocks, subsoils and hard clay pans, forming new channels that allow rain and surface water to reach underground reservoirs. Such a potential increase in groundwater recharge through watershed management may have significant impacts on water conservation. Williamson (1987) reported that 80 mm of storm rain that fell on a catchment with vegetative cover produced a lower peak flow than 20 mm of storm rain on a catchment without cover. He predicted that watershed vegetation could increase groundwater recharge by 33 percent. Khan and Chaudhry (1967) proposed that effective watershed management must be coupled with appropriate steps for maximum recharge and minimum soil erosion, including planting of trees, shrubs and grasses and constructing check dams, benching, loose-stone walls, spurs, ridges, ditches, contours, terraces and gabions. Recharge is higher in catchments with vegetation cover than in those without.

The United Nations Development Programme (UNDP) has planted various trees and shrubs under the watershed rehabilitation programme in Karak valley near Quetta in order to identify suitable species.

Trees, shrubs and grasses, natural and cultivated, in arid and semi-arid areas have a number of uses, including soil stabilization, control of water runoff and wind erosion, biological soil reclamation, groundwater recharge, rehabilitation of desertified lands, sand dune stabilization. They offer shade and make wind breaks, shelter-belts, barriers for wildlife and roadside hedges; they provide forage for livestock, seeds, edible fruits, honey and oils; they supply wood for carving, furniture, building, agricultural implements, poles and fires, and charcoal, gum, tannin and resin. Mulberry trees are the habitat of silkworms.

PROPOSED GROUNDWATER DEVELOPMENT PLAN

Groundwater investigations have established about 1 116 cusecs of groundwater potential, of which about 400 cusecs is currently being exploited. This means that about 716 cusecs of groundwater still remains to be developed by installing about 1 600 additional 1.00 cusec capacity tubewells (see Table 18).

Table 18. Groundwater potential and proposed number of tubewells

Area

Groundwater potential (cusec)

Tubewells installed
(0.5 cusec)

Balance ground water potential (cusec)

Possible tubewells at 50% op. factor

Proposed tubewells

Northeastern Bela Plain

15.0

4

13.0

26

4

Jhal Jao

24.0

12

18.0

36

5

Panjgur Sara-i-Paroon

32.0

20

27.0

54

6

Musa Khail Bazar

7.0

9

4.0

8

7

Gumbaz area (Loralai district)

24.0

8

20.0

40

4

Kalat area (Pishin Lora basin)

10.0

3

8.5

17

7

Saman Tangi Jhal, Wag and Badri area

10.0

5

5.1

10

2

Source: WAPDA (1994).

CONCLUSIONS AND RECOMMENDATIONS

Conclusions

Recommendations

REFERENCES

Ahmed, M. & Ahmad, R. 1993. Irrigation application techniques and their use in Baluchistan. P&I publ. no. 389. 32pp.

Abdullah, M. & Qureshi, J.D. 2000. Natural and artificial groundwater recharge techniques with special reference to Baluchistan. In Proceedings of the Global Water Partnership meeting on regional groundwater management. Islamabad.

Halcrow, A.D.B. 1996. Baluchistan groundwater assessment.

Bureau of Water Resources. 1995. Current groundwater monitoring network in northern Baluchistan. Quetta, Government of Baluchistan.

Bureau of Water Resources. 1997. Baluchistan water database. Quetta, Government of Baluchistan

Bureau of Water Resources. 1997. Pashin Lora basin groundwater level fluctuation report. Quetta, Pakistan, Government of Baluchistan.

CEWRE. 1997. Proceedings of the international symposium on water for the twenty-first century: demand, supply, development and socio-environmental issues. Lahore, Pakistan.

CEWRE. 2000. Baluchistan minor irrigation and agricultural development project: conjunctive water use pilot project study, Loralai (Dec. 1986). Lahore, Pakistan.

Government of Baluchistan. 1978. The Baluchistan groundwater rights administration ordinance. Quetta, Pakistan.

Government of Pakistan. 2000. Agricultural statistics of Pakistan (1998-99). Islamabad, Ministry of Food, Agriculture and Livestock. 291 pp.

Khan, A.R. & Chaudhry, M.A.H. 1967. Farming erodable lands in West Pakistan. Lahore, Pakistan, Bureau of Agricultural Information. 180 pp.

Khalil, M. 1993. Economic and financial evaluation of delayed-action and storage dams in Ziarat valley. Publ. No. 390. Lahore, Pakistan, Planning and Investigation Organization. 39 pp.

Khan, A.S. & Mian, B.A. 2000. Groundwater development issues of Baluchistan. In Proceedings of the global water partnership seminar on regional groundwater management. Islamabad.

WAPDA. 1992. Plan for rehabilitation and improvement of karezes in Baluchistan. Lahore, Pakistan.

WAPDA. 1993. Final report, irrigation systems management research project. Lahore, Pakistan, Planning and Investigation Organization.

WAPDA. 1993. Groundwater resources of Baluchistan province, Pakistan. Lahore, Pakistan, Directorate General for Hydrogeology. 200 pp.

WAPDA. 1994. Revised PC-1 proforma: groundwater development project in Baluchistan. Lahore, Directorate General for Hydrogeology.

Williamson, R. 1987. Impact of watershed works on hydrology near Quetta: final report on design of works and monitoring programme for Baluchistan watershed management sub-project. Sheddon Paufic Tty. Ltd.


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