Indian Water Resources – An Overview Dr. K.V. Devi Prasad Embassy of India, Berlin

India -facts Has many types of ecosystems – from deserts to tropical evergreen to alpine ecosystems Total area >3.3M sq. km. Population >1.1 billion Population is young and growing => Demand for food and water increasing

India Projected growth Economy expected grow rapidly More than 7% p.a. in the last decade and a half Population expected to grow to ~1.6 billion by 2050. roughly 50% increase Per capita growth rates are high

India – water resources at a glance

Indian Monsoon The largest weather phenomenon in the world Creates a distinct “rainy season” The rainfall is asymmetrically distributed Creates periods of excess and periods of shortage in water availability Even the rainiest place on earth can have water shortage for a short period!!

Rainfall in India from Rakesh Kumar, singh &Sharma 2005

Water – what the future holds! Gross per capita water availability will decline from ~ 1820 m3 /yr in 2001 to ~ 1140 m3 /yr in 2050. It was more than 5000 m3/yr in 1950!! Total water requirement of the country for various activities around the year 2050 ~ 1450 k m3 /yr. current estimate of utilizable water resource potential (1122 km3/yr)

The decline in water availability From Mall et al. 2006.

India – the land of Rivers Rivers are the basis of everything Rivers do not “drain” their catchments ; but they irrigate their deltas!! Most food production depends on river water irrigation – especially peninsular India

Major River Basins of India

Anticipated water requirements sectorwise [from Gupta & Deshpande, 2005]

Water Availability in Indian river Basins

What can be done? Problem is complex and there can be no simple solution Agriculture would still be the largest demand segment Changes in Agriculture practice may help Conventional rice farming requires ~1m per hectare per crop; Alternate wet & dry methods can save around 30%; SRI methods can save upto 50%

The way forward …. Conservation and reuse of waste water Most of non-agricultural use degrades the quality of water Poses the double problems of waste and pollution Conservation is key success Another area would be augmenting sources

Ground water recharge Rain water harvesting and ground water recharge are now recognised as important Mandatory in some urban areas 3 year deficient rainfall in Chennai in 2001,02 and 03 caused major problems But it has downside Water flow and sediment transport is important to oceans as well!!

Large dams??!! Would dams impounding water help/ Many criticisms of this approach Interference to hydrogeology Loss of biodiversity Catastrophic failure Sediment transport issues Some deltas of the world are sinking!! Rising seas and sinking deltas => human misery

Can we engineer on large scale Some river basins have some water to spare Can we transport water across the basins? Costs? Environmental consequences?

From Mishra et al. 2007

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