ISLAMABAD: With water stored in the Tarbela reservoir plummeting to an amount sufficient for the country’s irrigation requirements for only three days, the Indus River System Authority’s (Irsa) capacity to manage and plan the resource has come under serious threat owing to wide variation in hydrological data and non-implementation of its orders for water discharges.

An Irsa official told Dawn on Wednesday the water regulator was ‘really confused’ over variations in hydrological data coming from Wapda since early this week and perturbed over non-implementation of its instructions for water regulation in a timely manner.

Inflow in river Indus at the country’s largest Tarbela reservoir was reported at 32,000 cusecs in the morning on Tuesday, but it was 27,000 cusecs in the evening. It was 35,000 cusecs in the morning and 33,500 cusecs in the evening on Wednesday. “Such variation is unusual, more so when temperatures have not increased in northern areas,” the official said. Over the past three days, inflow in river Kabul has also changed a lot, increasing from 40,000 cusecs to 45,000 cusecs and further to 50,000 cusecs and then receding to about 36,600 cusecs on Tuesday evening and then slightly improving to 39,900 cusecs at 1800 hours on Wednesday. To some extent, this was understandable because of rains in its catchment areas, he said.

What worried Irsa here was that such a variation in Kabul and Indus did not make a mark at Chashma barrage. “There is no logical account of these additional flows” which are quite evident at Kalabagh but missing downstream to Chashma.

On top of that, Irsa directed Wapda authorities on Tuesday to reduce discharges from Tarbela dam from 40,000 cusecs to 30,000 cusecs. “Wapda did not reduce outflows from Tarbela dam but cut down releases from Chashma,” the official said, complaining that Irsa’s regulation mechanism had been badly disturbed.

As a result of fluctuations, Irsa has not been able to take a decision on Sindh’s 10 daily indents that it had sought to increase to 65,000 cusecs from May 1. Likewise, the regulator has failed to approve Punjab’s demand for increasing discharges through Chashma-Jhelum Link Canal to 10,000 cusecs from current flows of 5,000 cusecs the largest province has been seeking for quite some time.

Consequently, Irsa has been forced to continue with provincial irrigation indents of previous 10 days, ending on April 30 under which it was releasing 50,000 cusecs to Sindh and 81,000 cusecs to Punjab. Khyber Pakhtunkhwa and Balochistan are being provided 3,000 cusecs and 4,000 cusecs of water, respectively.

This is happening at a time when the water stored at Tarbela has dwindled to a critically low level of almost three feet, enough only for three days at prevailing discharge rate if Indus flows do not go up or Wapda does not reduce Tarbela outflows.

On Wednesday evening, water level at Tarbela dam was recorded at 1,381.32 feet against its dead level of 1,378 feet. “Because of preference for power generation, the irrigation priority is being badly affected and making it difficult for Irsa to manage provincial irrigation requirements,” said the official.

According to hydrological data recorded on Wednesday evening, Tarbela dam is receiving only 33,500 cusecs against its outflows of 40,000 cusecs. Water level at Chashma stood at 647.60 feet against its dead level of 637 feet as it received 70,471 cusecs and discharged 66,000 cusecs on Wednesday.

The water level in Jhelum river at Mangla dam stood at 1,108 feet on Wednesday against its dead end of 1,040 feet. Flows at Kalabagh upstream were recorded at 81,572 cusecs on Wednesday against downstream flows of 75,572 cusecs. Maximum temperature at Skardu was recorded at 20 centigrade where river flows were recorded at 33,900 cusecs against 36,000 cusecs at Besham.