At a time when uncertain monsoonal rain is upsetting farmers’ annual crop plan, significant drop in live storage capacity of Odisha’s major and medium reservoirs seems to have made the matters worse.
Odisha’s live storage (LS) capacity has dropped alarmingly by about 21 per cent during the past 10 years.
The aggregate live storage capacity of seven major and 38 medium reservoirs has shrunk from 1.43 million hectare metre (m ha. m) in 2006 to 1.12 m ha.m in 2015.
Many reservoirs were constructed in early 1970s. Hirakud, the largest reservoir in Odisha, was built in 1950s.
Till 2006 the aggregate LS of all reservoirs was 1.43 m ha.m, which was 87.31 per cent of full reservoir level (FRL) – a loss of around 13 per cent.
But the past one decade saw the LS capacity getting reduced at a faster rate from 87.31 per cent to 68.89 per cent, the State government said in response to a query in the Assembly.
Seven major reservoirs -- Hirakud, Rengali, Indravati, Upper Kolab, Balimela, Jalaput and Salandi -- had suffered a loss of 19.69 per cent from 1.33 m. ha.m to 1.07 m ha.m between 2006 and 2015. The loss of LS capacity of Rengali, Indravati and Salandi is real cause of concern. Rengali’s LS capacity has come down from 90.10 per cent to 59 per cent in 10 years. During the same time, Indravati’s capacity shrank from 90.51 per cent to 51.86 per cent.
The biggest loss was, however, experienced in case of Salani, LS capacity of which has gone down from 71.24 per cent to 12.74 per cent – a loss of mammoth 83.52 per cent between 2006 and 2015.
The comforting aspect in whole depressing situation is Hirakud. The loss of Hirakud’s capacity in the past 10 years has been estimated at 1.86 per cent from 0.43 m ha.m to 0.42 m ha.m.
In case of medium reservoirs, the aggregate LS capacity has dropped sharply from 63.72 per cent in 2006 to 38.10 per cent. Some of medium reservoirs are likely to become dead in near future. Reservoirs such as Jambira, Kunaria, Nesa and Sundar are now left with less than 10 per cent of their LS capacity. “The process of sedimentation is becoming quicker as there has been rapid loss of forest cover in the upper catchment of reservoirs, especially Hirakud. In some places, uncontrolled mining has also added to siltation,” said Ranjan Panda, convenor of Water Initiative of Odisha.
Mr. Panda pointed out: “During the past one decade, rise in temperature annually is breaking record of previous year and as a result of which evaporation loss has also been increasing.” Loss of water-holding capacity of reservoirs has been consistently directly affecting irrigation in several districts. Reservoirs were apparently of no use as far as providing water to crop field was concerned at several places during 2015 which was a drought year.