'Govt overestimated water availability'

If this is true, it could change the entire economic direction of the country. A paper published by researchers from IIT-Delhi and Jamia Milia Islamia has claimed that the government has overestimated the utilisable water resources of the country by up to 88% and India had breached its water security levels way back in 1997-98 by overexploiting the resource.

Published in 'Current Science', India's leading science journal, the study by N K Garg of IIT-Delhi and Q Hassan of Jamia Milia Islamia claimed that the government overestimated water available for use by a whopping 66-88% by double accounting for the resource in their methodology.

The findings could be a wake up call for planners and have a huge impact on India's estimate of water resources, possibly leading to a recast of plans for regulation and development of power and irrigation schemes. The authors claimed, on the basis of four years of work, that India had only 668 billion cubic metres (BCM) of water compared to 1,110 BCM claimed by the Central Water Commission — less by 442 BCM. This is alarming considering that even the projected demand (and this is the lower side of projections) of 987 BCM cannot be met even after all the available water is exploited.

In water jargon, development of water resource refers to creating the structures to use different water resources — surface water or ground water. The entire water available in a country, in its rivers and under the ground, obviously cannot be used. The portion that hydrologists conclude can actually be extracted and put to use is referred to as "utilisable water resource". Over exploitation in any year implies extracting more water than is naturally recharged in the river basin in that year. "What the government has done is double accounting of one vital element of the water cycle and therefore ended up with an inflated figure. While the error looks simple, with the ground water data of the country being classified, it took us four years of digging and understanding the method of calculation to figure out this discrepancy," Garg, from the department of civil engineering, IIT-Delhi, told TOI.

Cutting through the reams of data and calculations mentioned in the paper, Garg explained, "During the lean period, the water in rivers that one sees is actually ground water as there is no rain at the time. But when the CWC calculated total utilisable water, it accounted for the water in the rivers at the time as surface water as well as ground water, leading to the inflated figures." It sounds so much a clerical mistake but A K Gosain, also from the civil engineering department of IIT-Delhi and on the PM's expert committee on climate change, said, "The trouble is all the data on ground water is classified and never released to even scientists. Nobody outside the government has been able to evaluate the statistics. Even when we were doing simulation studies to look at impact of climate change on our rivers, we had to use American data on Indian rivers to validate our results."

Source: TOI , 27 oct 2007