LAHORE: With rising temperatures, the water supplies in the country have also gone up by around 44 per cent in comparison to the last year’s river flows, with the Indus and Kabul registering main improvements of 30pc and 11pc, respectively.

Though the River Jhelum’s flow has fallen by 21pc and the Chenab by 5pc, the combined improvement of 41pc in the Indus and Kabul rivers has given a huge boost to overall supplies — raising them from 241,000 cusecs last year to 348,000 cusecs this year — an increase of 31pc, or 107,000 cusecs.

According to the data of the Water and Power Development Authority (Wapda), the last five-year cumulative average supplies for June 8 have been 274,400 cusecs and 10-year average stood at 268,400 cusecs.

According to the data of the Indus River System Authority (Irsa), the country now holds six million acre-feet of water in its three reservoirs — 1.6maf in Tarbela, 4.22maf in Mangla and 0.2maf in Chashma. This storage was 7.9maf on the corresponding day last year. Irsa says this year’s drop in storage has been caused by the Tarbela Dam extension project which has restricted water levels to 1,482 feet till July 15.

That is why Irsa had to release additional water from the Tarbela Lake to keep it within the permissible limit, otherwise the storage situation could have been much better. During April 1 to June 7, some 1.04maf water was sent downstream Kotri for irrigation and drinking purposes, which normally is not sent at this point of time.

According to an Irsa official, the drop in the Jhelum and Chenab has been caused by thin snow in their catchments areas, leaving them totally dependent on monsoon rains. Since there has been no heavy shower this season so far, the flows in both of them have dropped. However, the largely glacier-fed Indus arm is now responding to high temperatures in the upper region.

Skardu on Tuesday had a hot day with the maximum temperature of 30 degrees Celsius and minimum 23 degrees. Last year, its temperatures ranged between 12.8 and 16.7 degrees. This rise in temperature has pushed the Indus to 172,600 cusecs and the Kabul to 66,900 cusecs. Last year, the Indus was flowing at 86,600 cusecs and the Kabul at 61,600 cusecs.

Because of these additional supplies and the constraint of keeping Tarbela Lake at 1482 feet, Irsa has been supplying extra water to the provinces. Against a demand of 129,000 cusecs, Punjab is getting 145,000 cusecs. Sindh is getting 170,000 cusecs against its demand of 144,000 cusecs. Irsa is also operating the Chashma-Jhelum and Taunsa-Panjnad link canals.

“With massive water availability on the Indus arm, Irsa has started squeezing releases from the Mangla Lake,” says the authority’s spokesman Rana Khalid. The releases from Mangla were kept at 25,000 cusecs only and on Tuesday even those were cut to 22,000 cusecs so that more water could be conserved there.

About the impact on Tarbela filling, he said Wapda had promised to fill the lake by 18 inches a day instead of 12 inches after July 15 and make up for the time loss. Thus it should not hurt the chances of dam filling, he claimed.

Published in Dawn, June 9th, 2016