Storage in Cauvery basin reservoirs has dipped to nearly half their gross capacity

The water level in the four major reservoirs in the Cauvery basin of the State has dipped to nearly half of their cumulative gross capacity and is a pointer to the unfolding crisis in the weeks ahead.

The available quantum should not only meet the drinking water requirements of major towns and cities, including Bengaluru and Mysuru, but should last till the onset of monsoon next year which is sometime in June.

The cumulative storage in Krishnaraja Sagar (KRS), Kabini, Hemavathi, and Harangi was 59.07 thousand million cubic ft (tmcft) as on Saturday 18 as against the gross capacity of 114.57 tmcft or 51.56 per cent of the storage capacity. The storage position in the reservoirs during the same period last year was 100.69 tmcft.

Water level at the KRS was 100.62 ft on Saturday as against the full reservoir level of 124.80 ft and the live storage was 23.30 tmcft as against the gross capacity of 49.45 tmcft. The storage position on the same day last year was 46.84 tmcft.

At Hemavathi reservoir, the level was 2,893.73 ft as against the FRL of 2,922 ft. The live storage was 16.23 tmcft as against the storage capacity of 37.10 tmcft, and the storage position on the same day last year was 32.92 tmcft.

The gross storage capacity of Kabini is 19.52 tmcft as against which the available storage on Saturday was 14.32 tmcft while at Harangi the quantum of water available was 5.23 tmcft as against the storage capacity of 8.50 tmcft.

Northeast monsoon

Having suffered a 26 per cent rainfall deficiency during the southwest monsoon season, the northeast monsoon pattern shows a 31 per cent deficiency in south-interior Karnataka.

Though the region is not a major beneficiary of northeast monsoon, it has not received even the nominal quantum that could have increased moisture index and helped recharge groundwater level to an extent and reduced the dependence on dam.

As against the normal rainfall of 178 mm for the period October 1 to November 19, the region received 124 mm. Though the period November 1 to 19 was relatively better with the region receiving 75 mm of rains as against the normal of 40 mm, the overall rains continue to be 31 per cent below normal. The cumulative deficiency since June 1 is now 28 per cent, according to Karnataka State Natural Disaster Monitoring Centre.

Of the 11 districts in the region only Mysuru district has received rains that is 9 per cent above normal for the period October 1 to November 19. It received 205 mm of rains during the period as against a normal of 188 mm while Mandya has received 180 mm as against a normal of 194 mm during the same period, the deficiency being 7 per cent.

But with respect to other districts that include Chamarajanagar, Ramanagara, Bengaluru Rural, Chickballapur, Kolar, Tumakuru, Davangere, Chitradurga, and Bengaluru Urban the deficiency ranges from 26 per cent to 55 per cent which will accentuate the drought conditions.