Water Resources in the Indus-Gangetic Basin

Bharat Sharma Basin Focal Project for the Indus-Gangetic Basin Water Resources in the Indus-Gangetic Basin http://bfp-indogangetic.iwmi.org:8080/

The Indus- Gangetic Basin • 255 M ha drainage area across 4 major and 2 minor countries. • 747 million people (2001, Census) • Physical and economic water scarcity. • Both covered under 10 most endangered rivers (WWF) http://bfp-indogangetic.iwmi.org:8080/

Indus River Basin • 110 M ha area • Mount Kailash in Tibet • Indus Water Treaty • Annual system inflow of 175 BCM (CV~ 13%) • Snow and ice melt form a large part

Changing pattern of surface irrigation diversions in the IBIS, Pakistan • 15 barrages • 45 main canals • 14 river-link canals

Water Resources in the Ganges Basin • Gangotri glacier in Gomukh • 1.09 m km2 ( 79-I, 13-N, 4-C, 4-B) • Tehri Dam, Farakka Barrage BCM

Whole basin annual precipitation and runoff from 1951 to 2000 in the Ganga Basin

Ganges Basin Water Use • Ganges basin has high annual average rainfall of more than 1000 mm, averaged across the basin, and 2000 mm or more in Himalayan catchments. • Net discharge from the Basin accounts for more water than any other use, followed by rainfed agriculture. • The impact of increasing irrigation efficiency ( from 40 to 60%) has relatively little impact on water availability overall. However, increase in irrigated area may lead to overall net increase in water consumption and a marginal impact downstream. McKirby et al, 2009

The spatial distribution of major water uses in catchments of the Indus and Ganges Basin McKirby et al, 2009 Ganges basin Indus Basin

Summary of major water uses in the Indus and the Ganges Basin Indus Basin Ganges Basin McKirby et al, 2009

Groundwater Recharge in Indus- Gangetic Basin

Groundwater availability and its use in the Indus-Gangetic Basin

Decadal increase in tubewell irrigated area in Indus-Gangetic Basin countries

Groundwater quality in IG basin Rechna-Doab, Pakistan IG Basin states, India

Predicted arsenic contamination in ground waters of Ganga basin

Ganga River Basin Annual water balance components Source: Gosain, AK, IIT_D

Ganga River – Annual Peak Source: Gosain, AK, IIT_D

Events exceeding arbitrary thresholds in Ganga River Basin Source: Gosain, AK, IIT_D

The Indus System • In terms of infrastructure for water storage and irrigation, Indus basin is well developed . However, lack of proper maintenance and management of reservoirs and canal systems is seriously impacting the dry season cultivation. • Most of the available water in the Indus basin is already committed leaving only bare minimum for the environmental flows. • Indus basin is also one of the biggest groundwater usage regions and hot spot in the world. With such a high stress on water resources, the basin needs to employ demand management options to foster sustainable use. • Decrease in groundwater recharge and drop in extent of snow cover induced by climate change can have serious impacts on base flow.

The Ganges System • Ganges basin, in contrast, exhibits poor development and inefficient utilization of its resources. • Need for investments in bulk water storage to take advantage of the resources and alleviate flood damages. • River/ groundwater pollution and heavy dependence of urban centers and industry on the surface water supplies is a major cause of concern for future expansion. • Rich endowment of groundwater resources in the basin largely remains under-utilised. • Extreme climate events with large flood volumes and lack of storage structures may further worsen the flood regimes

Water Resources in the Indus-Gangetic Basin