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Water storage in dams a concern for power generation

September 24, 2009 09:23 IST

Water in a damThe withdrawal of the monsoon is already delayed by over three weeks. This has benefited the kharif crops and raised hopes of good rabi sowing but has not managed to wipe out the shortage of water storage in major dams.

The total water stock in the country's 81 major reservoirs is still 57 per cent of their live storage capacity, falling 12 per cent short of the normal level for this time. This is a cause for concern for both irrigation and hydro power production.

On the positive side, despite about 21 per cent deficiency in the monsoon rainfall till mid September, the area sown is down by just 7 per cent from last year's level, according to the crop-weather watch group of the agriculture ministry. More data on kharif sowing is still pouring in and the situation might improve further due to the belated surge in rainfall in the last week of August and first week of September.

The outlook for the production of coarse cereals, pulses and cotton has improved thanks to larger plantings and belated rainfall that has benefited the standing crops. But that is not the case for paddy and oilseeds, especially groundnut, due to poor sowing.

The output of soybean and sugarcane may be close to last year's level as showers in July and again in August and September have been highly favourable for these crops.

Where water storage in key dams having significant irrigation and power production potential is concerned, the situation is still far from satisfactory.

In the north, while Bhakra (having irrigation command of 67.6 lakh hectares and power production potential of 1200 Mw) is filled up to 63 per cent of the live storage capacity, against normal 83 per cent, Thein dam (34.8 lakh hectares irrigation and 600 Mw power) carries just 31 per cent water.

The situation in Ramganga in Uttarakhand is even worse with just 19 per cent filling this year.

Similarly, Ukai and Kadana dams in the western region are filled just up to 55 per cent and 67 per cent of their capacity, respectively. Indira Sagar in Madhya Pradesh, having a large irrigation command area of 23.8 lakh hectares and installed power production capacity of 1000 Mw, is only 63 per cent full.

In south, water level in Nagarjuna Sagar is just 17 per cent where as normally it should be close to 60 per cent at this time of the year. Water level in Mettur is reckoned at 61 per cent which is almost the same as last year.

On the whole, the total water storage in 81 major reservoirs was estimated by the Central Water Commission at 85.98 billion cubic metres on September 17 this year, against 104.38 BCM on this date last year and past 10 years' average storage of 98.81 BCM.

The relatively low water storage is attributed to the performance of the monsoon which is worse in the past five years. Of the total 36 meteorological subdivisions, only 13 have had either normal or above normal rainfall while the rest 23 subdivisions fall in the deficient category.

This compares poorly even with 2004 when the country experienced moderate drought. In that year, 22 sub-divisions fell in normal category and 14 in deficient bracket.

In terms of meteorological districts, about 43 per cent of them have reported normal and excess rainfall and 57 per cent deficient or scanty rainfall till mid-September.

The latest sowing data gathered by the agriculture ministry till September 17 puts paddy planting at 31.54 million hectares, about 6 million hectares short of last year's 37.65 million hectares. The shortfall is confined mainly to Uttar Pradesh, Bihar, Jharkhand, Madhya Pradesh, Andhra Pradesh and West Bengal.

The area under pulses has expanded this year to 9.77 million hectares, against last year's 9.28 million hectares thanks to larger plantings of moong in Karnataka and urad in Madhya Pradesh.

Oilseeds have witnessed a drop in acreage -- from 17.97 million hectares last year to 16.74 million hectares this year. This is due largely to about 7.5 lakh hectares lesser sowing of groundnut in Andhra Pradesh and Gujarat.

Cotton has been planted over about one million hectares additional area mainly in Gujarat, Maharashtra and Rajasthan. The bulk of this acreage is under pest-protected Bt cotton hybrids. Crop in most areas is in good shape.

Surinder Sud in New Delhi
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