Upali Amarasinghe

Water accounting in the IGB

IGB water accounting

• Water availability in the IGB

• Irrigation demand

• Total water demand

• Water accounting

• Food accounting

Per capita water availability

– IGB-India has 38% of the total renewable water resources, and

– 49% of the total population in 2000

– BIMARU states of India and Bangladesh, encompassing Ganga basin, have

significantly high population growth rates,

– Indus has decreasing population by 2050

– Ganga basin has 42% of the population in 2000, and 55% in 2050

Total renewable wate resources/person (m3)

-

500

1,000

1,500

2,000

2,500

3,000

Indus- India Ganga - India Other - India Indus-

Pakistan

Bangladesh

m3

1990

2000

2025

2050

Utilizable water resources

• IGB share only 33% TRWR

• Of this only 57% is utilizable

• Climate change can be a threat to utilizable water resources

• Augmenting PUWR through GW recharge

Utilizable water resources

0%

20%

40%

60%

80%

100%

Indus Ganga Others

Sh

are

(%

)

0

400

800

1200

1600

2000

TR

WR

(km

3)

Surface water-utilizable Groundwater utilizable

Un-utilizable resources Total water resources

Water demand

• IGB account for 56% and 58% of the total and irrigation water

withdrawals

• In Ganga, 90% of the withdrawals for irrigation

• In Indus 97% of the withdrawals for irrigation

131

[46%]

11[4%]

17 [6%]

125

[44%]

Irrigation -

Surface

Irrigation -

Groundwater

D&I -

Surface

D&I

Groundwater

Water withdrawals (km3)2

[2%]3, 1%

57

[58%]

37

[38%]

Indus basin

Water accounting in Ganga basin

• 55% is of TRWR is potentially utilizable

• 45% of PUWR is depleted in 2000

– Not physically water scarce now

• Groundwater abstraction ratio - 56%

Water Availability

Ganga Basin

275 km3

[45%]

388 km3

[55%]

250 km3

[36%]

138 km3

[25%]

Not-

Utilizable

Utilizable -

Surface

Utilizable -

Groundwater

Over

lap

34

Water accounting of utilizable water supply

Ganga basin

214 km3

[55%]174 km3

[45%]

29%

6%

10%

Unutilized

PUWR

Process

evaporation

Non-process

evaporation

Unrecoverabl

e return flows

Water accounting in Indus basin

• 61% is of TRWR is potentially utilizable

• 82% of PUWR is depleted in 2000

– Physically water scarce now

• Groundwater abstraction ratio 67%

Water Availability in the Indus Basin

33 km3

[39%]

67 km3

[61%]

46 km3

[36%]

21 km3

[25%]

Not-

Utilizable

Utilizable -

Surface

Utilizable -

Groundwater

Over

lap

6 km3

Water accounting of utilizable water supply in

Indus basin

12 [ 8%]

7 [11%]

36

[ 53%]55

[82%]

12

[18%]

Unutilized

PUWR

Process

evaporation

Non-process

evaporation

Unrecoverabl

e return flows

Food accounting

• Substantial food production surpluses in Indus

– More than the production deficits of all other river basins

• Is it sustainable?

• More crop drop!!!!

34

98

74

9

95 97

25

3

-23

Indus Ganga Others

Production Consumption Production surplus

Thank you