Around 50,000 cusecs of water gushed out of the Attabad Lake in Hunza after Pakistan Army engineers dynamited the temporary blockade on the lake’s spillway, witnesses and officials said on Monday.
“So far the situation is under control since the outflow of water isn’t too dangerous to affect the population downstream,” an army spokesman told The Express Tribune soon after the blasts that were carried out in the presence of Gilgit-Baltistan (G-B) Chief Minister Mehdi Shah and G-B Force Commander Major General Ikramul Haq.
The spillway had been blocked recently to further deepen it. However, it is believed that the blasts wouldn’t completely drain the lake that has submerged part of the Karakoram Highway and four villages upstream.
According to the army spokesman, the blasts which were carried out at about 2:00 pm, brought down the water level by approximately four inches of the 22 kilometres-long lake that was formed more than two years ago after a massive landslide struck Attabad, killing 19 people. The debris had blocked the Hunza River, forming a lake and effectively cutting off about 25,000 people from the rest of the country.
Before the blasts, hundreds of people gathered in Hunza expecting to see a huge outflow of water in the Hunza River, however, the level of water passing beneath Ganish Bridge – about 10 kilometres downstream spillway – was only slightly greater than that of the river during summer, said Asad Hussain, a resident of Hunza.
The army spokesman added that the discharge of water would turn normal within three days, adding that all precautionary measures had been taken in advance to avoid human loss.
Not much difference in Tarbela
Meanwhile, the blasts at the Attabad Lake would barely increase the water table in the gigantic Tarbela reservoir, official sources at Tarbela Dam told The Express Tribune.
It was revealed that around 50,000 cusecs of water was expected to enter Tarbela Lake at around 9:00 pm and would have virtually no efect on the water table because it is a very small quantity which could hardly create flood-like situation.
Sources believe that the situation could have been a bit different during July and August when the reservoir is almost filled to the maximum conservation level.
“But now Tarbela Lake is already nearing the dead level as the irrigation discharge, following the decision of the Indus River System Authority (IRSA), is four times more than the inflow,” said an official, referring to statistics of measuring the water table in the reservoir.
According to official data collected on Monday afternoon, the inflow of water was 10,200 cusecs, outflow 55,000 cusecs and water table stood at 1406.5 feet while power generation from ten out of 14 power generating units was 1,174 megawatts.
Responding to a question, the official said that owing to snowfall and chilly weather in the catchment areas of upper Hazara and Northern Areas the inflow of water had decreased while the outflow was four times more than the inflow.
“The reservoir is left with only 28 feet of water which is expected to exhaust by March 10, leaving Wapda with only one option of operating the spillways on run of the river,” said the official, requesting anonymity. The 97 sq km long Tarbela reservoir has a dead level of 1,378 feet while the maximum conservation level stands at 1,450 feet.
Published in The Express Tribune, February 28th, 2012.