Water accounting in the IGB
Upali Amarasinghe

IGB water accounting
• Water availability in the IGB
• Irrigation demand
• Total water demand
• Water accounting
• Food accounting

Per capita water availability
Total renewable wate resources/person (m3)
3,000
2,500
1990
2,000
2000
m3 1,500
1,000 2025
500
2050
-
Indus- India Ganga - India Other - India Indus- Bangladesh
Pakistan
– 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

Utilizable water resources
Utilizable water resources
100% 2000
80% 1600
TRWR (km3)
Share (%)
60% 1200
40% 800
20% 400
0% 0
Indus Ganga Others
Surface water-utilizable Groundwater utilizable
Un-utilizable resources Total 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

Water demand
11[4%] Water withdrawals (km3)
2 3, 1% Irrigation -
[2%]
17 [6%] Surface
Irrigation -
125 Groundwater
[44%] 37 57
[38%] [58%] D&I -
131 Surface
[46%]
D&I
Groundwater
Indus basin
• 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

Water accounting in Ganga basin
Water Availability Water accounting of utilizable water supply
Ganga Basin Ganga basin
Unutilized
Not- PUWR
250 km3 Utilizable
[36%] Process
29%
Utilizable - 214 km 3 evaporation
275 km 3 388 km 3 Over Surface [55%]
174 km 3
[45%] [55%] [45%]
lap Non-process
34 Utilizable - 6% evaporation
138 km 3 Groundwater
10% Unrecoverabl
[25%] e return flows
• 55% is of TRWR is potentially utilizable
• 45% of PUWR is depleted in 2000
– Not physically water scarce now
• Groundwater abstraction ratio - 56%

Water accounting in Indus basin
Water Availability in the Indus Basin Water accounting of utilizable water supply in
Indus basin
Unutilized
Not- PUWR
Utilizable
46 km3 36 Process
3 3
[36%] Utilizable - [ 53%] evaporation
33 km 67 km Surface 12 55
Over
[39%] [61%] [18%] [82%] Non-process
lap
6 km3 Utilizable - 7 [11%] evaporation
3 Groundwater
21 km 12 [ 8%]
Unrecoverabl
[25%] e return flows
• 61% is of TRWR is potentially utilizable
• 82% of PUWR is depleted in 2000
– Physically water scarce now
• Groundwater abstraction ratio 67%

Food accounting
98 95 97
74
34
25
9
3
Indus Ganga Others
-23
Production Consumption Production surplus
• Substantial food production surpluses in Indus
– More than the production deficits of all other river basins
• Is it sustainable?
• More crop drop!!!!

Thank you