Long spell of below normal rain leaves western and southern India parched

This year has produced an exceptionally prolonged dry patch. The 2018 June-September monsoon season produced rainfall that was only 91 per cent of the normal. Anything below 95 per cent of normal rainfall in the monsoon season can lead to stress.

Behind the severe water crisis in Maharashtra, Gujarat and many parts of south peninsular India, is an unusually long stretch of below-normal rainfall across the country. Since July 2018, there has been just one month, this February, that the country received rainfall in excess of the monthly normal. Each of the other months have been deficient, something that has not happened in the last several years.

Even in February this year, the Marathwada region of Maharashtra, which is among the regions facing the most acute water shortage, received practically no rain. North interior Karnataka, another area badly affected, also received lesser rainfall in February. Marathwada, which is heavily dependent on water tankers now for its drinking water needs, has not had a normal monthly rainfall since July last year.

However, water shortages at this time of the year are not uncommon. More than 70 per cent of the rains in India come during the four-month monsoon season. This is the time that most reservoirs in the country swell up, and this water is then used for irrigation, drinking water, industrial use, and hydroelectricity for the rest of the year. By April and May, the country eagerly awaits the next monsoon to replenish its resources.

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But this year has produced an exceptionally prolonged dry patch. Consider this: the 2018 June-September monsoon season produced rainfall that was only 91 per cent of the normal. Anything below 95 per cent of normal rainfall in the monsoon season can lead to stress.

Then, the northeast monsoon, or the winter monsoon, which brings substantial rains to the southern peninsular region, especially Tamil Nadu, in the months of October, November and December, was 11 per cent deficient. The country as a whole saw a 43 per cent deficit in its rainfall during these months.

The first two months of 2019 were slightly better, with January seeing a deficiency of just 4 per cent, and February producing rains that were 48 per cent more than the monthly normal. But January, February and March see very little rain in any case, so even a large positive deviation in percentage terms does not count for much.

Also, the pre-monsoon period of March to May was again deficient by 24 per cent for the country as a whole. And this was compounded by a delayed monsoon which set in a week later than its usual date, and is finding its northward progression halted by a cyclonic storm in the Arabian Sea. June thus far has a 46 per cent deficiency.

“We seem to be passing through an unusually elongated dry spell. I have not looked at the data but I think areas in Maharashtra are staring at a one-in-25-year situation. This is not normal,” said Madhav Chitale, an eminent water expert who has served as chairman of the Central Water Commission and Union Water Resources Secretary in the 1980s.

The amount of overall rainfall is not the only thing that determines the state of the water situation in the country. The spatial distribution of rainfall, particularly in the catchment areas of reservoirs, is also crucial. So, while rainfall has been way below normal for most of the last year, the reservoirs are not doing all that bad — except those in the western and southern regions.

The water storage in the 91 major reservoirs of the country at the end of last week was 30.46 billion cubic meters, which is 19 per cent of its total live capacity. This is not unusual at this time of the year. In fact, it is better than last year, and also better than the average of the last ten years, which is considered normal.

However, a look at the reservoirs in western and southern India exposes the problem. The 27 major reservoirs in the western region — Gujarat and Maharashtra — were together holding just 11 per cent of their combined live capacity. At this time of the year, they should be holding at least 18 per cent.

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Similarly, the 31 reservoirs in the five southern states were filled to just 11 per cent their combined storage capacity against a normal of 15 per cent at this time of the year.

The reservoirs in Maharashtra and Andhra Pradesh are the driest right now, with deficiencies of 64 per cent and 84 per cent respectively.

And even as per capita water availability has been consistently decreasing due to population pressure — it reduced from 1,820 cubic metres per year in 2001 to 1,545 cubic meter in 2011 — A B Pandya, former chairperson of the Central Water Commission, said addressing the water shortage was more about effective management than anything else.

“For example, drinking water, and water for cattle and other animals take precedence over everything else. Together, this takes just about 5 per cent of total water availability in the country. This can easily be kept reserved. But often we see even this water is released in the anticipation that rains will replenish. This is extremely unwise. Usage of water for different needs need to be prioritised and the consumption must follow this priority,” he said.

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