AHMAD FRAZ KHAN
LAHORE: The raised Mangla dam may replace Tarbela as the country’s biggest water reservoir if rain forecasts for the next two months prove to be correct. Weather experts expect above-average rain during August and September.
On Tuesday, the Mangla lake level hit 1,208.55 feet, storing 4.92 million acre feet (MAF) of water. When it touches its maximum level of 1,242 feet, it will hold 7.6MAF. Tarbela can hold a maximum of 6.4MAF of water.
The lake is also close to beating its previous record of 1,212 feet. Even if it does not hit the maximum level, it is expected to emerge as the biggest reservoir this season.
According to the water planners, the lake still has around 60 more days of better, even exceptional, inflows.
The rain forecast for the next two months set the optimistic pattern: rain in catchments areas would help fill the lake and in other areas reduce the irrigational requirements.
“The expected climatic hydrology this year generated those hopes,” said an official of the Indus River System Authority (Irsa).
The Mangla dam is though 27 feet below the planned level by the end of July, it is still 55 feet above where it was last year on the corresponding day. But the deficit would probably be offset by the meteorological predictions that show above-average rain during the next two months.
No one is sure about the quantum of water that rains can generate, but the authority is hoping to take the lake as much closer as possible to optimum level of 1,242 feet on the basis of those showers. In that case, the lake would hold some three million acre of additional water, with a total of 7.6 MAF.
Realistically speaking, no one is expecting it to hit 1,242 feet level unless some exceptional rains hit the catchments areas but it would certainly end up improving its previous record by far and inching closer to the digit, he said.
The Punjab is already conserving maximum water and running the dam at minimum possible releases for the last few weeks,” claims an official of the provincial Irrigation Department.
For the last few weeks, only 15,000 cusecs are being released to support 13 million acres in the lower and upper Jhelum canals systems. Since these areas cannot get water from any other source, these releases are departmental compulsion. Beyond them, every drop is being conserved.
Luckily, River Chenab is supporting the system with better flows, allowing the province to save maximum water at the Jhelum arm, he said.
The province, like Irsa, is also hoping for better rains in the next eight weeks. Though the Punjab was expecting the dam to hit maximum level by mid-August, but below normal rains during July restricted the filling to its current level.
But it is expecting that next above-average rains in the next two months would make up for the losses and take the lake to a record, and possibly optimum, levels, he concluded.