Indian government may have grossly overestimated water supply

Treehugger: "Delhi, we have a problem" – at least according to a paper recently published in Current Science by researchers from the elite Indian Institute of Technology (IIT) and Jamia Milia Islamia (National Islamic University) in Delhi which claims that the Indian government has overestimated utilizable water resources anywhere from 66 to 88 percent due to a flawed methodology.

"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," says N.K. Garg of IIT, one of the study’s authors.

According to both authors Garg and Q. Hassan of Jamia Milia Islamia, India had only 668 billion cubic metres (BCM) of water compared to 1,110 BCM claimed by the Central Water Commission (CWC) – which is a shortage of 442 BCM. With a projected demand of 987 BCM, it cannot be met even after all the available water is exploited.

Garg explains that: "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 utilizable 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."

In hydrological terms, total utilizable water also includes water that cannot be used, such as water in rivers and underground. By including it in their calculations, the Indian government was able to present a much higher figure than what could actually be extracted and put to use. Obviously, this stupendous overestimation will have significant ramifications on the direction of India’s plans for water use, regulation and conservation, as well as for power and irrigation projects.

But could it be a clerical mistake? A.K. Gosain of IIT-Delhi, who also sits on the Prime Minister’s committee on climate change, doesn’t think so. "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."
::Times of India...