LAHORE: Despite an early onset of summer in mid-March and April getting hotter than usual, the snow melting process in mountainous and hilly areas has not picked up pace, putting profound pressure on the national water supplies and making the planners quite nervous.

For the last 10 days, national water supplies have dipped substantially below not only last year’s levels, but average supplies of the last five or 10 years for the day, forcing Pakistan to start its Kharif season with close to a 40 per cent shortage in both of its water-producing systems — 30pc in Indus and 10pc in the Jhelum arm.

“The situation is more precarious in Mangla, which is hosting less than 1pc of its capacity,” says Khalid Rana of the Indus River System Authority (Irsa).

On Saturday, Mangla held only 354,000 acre-feet against over seven million of its capacity. This is largely because the Mangla Lake is mainly rain-fed and there has virtually been no rain during March. The Met Office predicted five spells of rain, but only one took place.

“To make matters worse, 37 inches of snow fell this winter against the yearly average of 50 inches — a drop of 26pc. Even those 37 inches seem to have fallen on higher altitudes, where the temperature needs to be more than the current 23 degrees Celsius to melt it. These trends — less and high altitude snow and virtually no rain — have created a crisis in the Jhelum arm,” Mr Rana explains.

“The same trend seems to have impacted River Chenab as well,” explains an official of the Punjab Irrigation Department. The flows are improving, but too slowly to benefit the system — widening the gap between demand and supply.

On Saturday, the river was flowing at 22,000 cusecs against the last 10-year average of 25,000 cusecs. The Saturday flows included almost 30pc improvement; otherwise, it was flowing at 15,000 cusecs when the month started. So, the entire water-producing system has receded to a low level, and is not benefitting from the high temperatures, the official maintains.

The national water flow data, compiled by the Water and Power Development Authority (Wapda), explains the extent of water poverty. On Saturday, the country received 90,000 cusecs in all its rivers against the last 10-year average of 137,700 cusecs — a drop of 27.73pc.

Individually speaking, Jhelum provided 27,200 cusecs against its 10-year average of 48,200 cusecs; River Kabul was flowing at 12,900 cusecs against the average of 32,600 cusecs; Indus provided 27,500 cusecs against its average of 31,200 cusecs and Chenab chimed in with 22,200 cusecs against the average of 25,700 cusecs.

“Even the temperatures in Skardu have doubled — from 11 degree Celsius last year to 22.2 degree on Saturday — but snow melting has not increased,” says a Wapda official dealing with the snow and its melting phenomenon. “We can still give a benefit of the doubt to river flows as they involve two to three days of lag when water leaves the mountains and reaches Tarbela Dam. The entire snow will eventually reach the rivers, but the current delay remains a cause of concern.

“Tarbela and Mangla lakes are almost at dead level and not improving due to the absence of rains and snow melt,” Sahibzada Khan, director general of the meteorological department, said.

The trend is expected to hold for another month or so before it improves by the end of May or beginning of June, when both high temperatures and rains would start benefitting the system.

Published in Dawn, April 10th, 2022