Stakeholders puzzled over ministry’s decision to restrict Tarbela Dam filling

LAHORE: Ministry of Water and Power and Wapda have abruptly restricted filling of Tarbela Dam, posing serious concerns regarding smooth supply of canal water in the coming months, it was learnt on Wednesday.

According to documents and data available with The News, water impounding into Tarbela Dam was going at the rate of 4.5 feet a day to 2.5 feet per day since it touched the level of 1,500 feet on July 15, 2017.

However, as soon as the level of the dam reached 1,520 feet above the mean sea level, its daily filling was slowed to one foot per day by the ministry, citing serious safety issues. The decision in this regard was taken at a meeting, which was chaired by Khawaja Asif, federal minister for water and power, last week.

The decision of the committee has confused many stakeholders, including the Indus River System Authority (IRSA), the prime regulator of river water in the country. It was also against the consensus reached by different stakeholders, following extensive deliberations and correspondence over the filling criteria of Tarbela Dam during several meetings held last year.

Wapda, which was responsible for dam operations, led that exercise and communicated consensus formula to all stakeholders on April 17, 2017. Based on discussion and comments of geotechnical hydraulic experts in the three meetings, Tarbela Dam general manager wrote in his letter that filling of Tarbela Dam could be accelerated to five feet per day between 1,500 feet to 1,510 feet, which could further be accelerated to 10 feet per day in special circumstances.

His letter said that three feet per day filling should be done during 1,510 to 1,530 feet, while two feet per day level should be increased between 1,530 and 1,540 feet. He further said from 1,540 feet to 1,550 feet (maximum conservation level of dam), one foot per day filling pattern should be followed.

The letter also mentioned revised criteria for water-short years, which was recommended by the inspection team for current year with a view to ensure filling of the dam to the maximum conservation level.

According to swift filling pattern, water impounding into dam at the rate of five feet per day was proposed during 1,500 feet to 1,530 feet (meeting 80 percent of irrigation demand), two feet per day during 1,530-1,540 feet and one foot per day during 1,540 to 1,550 feet.

However, despite technical recommendations about agreed Standard Operating Procedure (SOP), the ministry has slowed down the filling process, which was likely to result in non-filling of dam to full storage level.

Expressing expressed on the development, sources said the ministry has no technical expertise about taking any stand over the dam’s filling criteria. “This task was already done by relevant technical persons,” they said.

Sources also said low level of water storage at River Indus would create serious water shortage problems during late Rabi and early Kharif season.

When contacted, spokesman of the Ministry of Water and Power said the Ministry should not be blamed for taking such decision. The decision to restrict filling of dam to one foot per day was taken by the participants of the meeting keeping in view the lack of proper mechanism to monitor the safety of dam infrastructure. “It should not be considered as an intervention of the ministry,” he stressed.

“The safety of the dam assumes paramount importance and we cannot overlook this very important aspect,” he said, and added that it was decided as a safety precaution.

The spokesman said the filling pace should be reduced by one foot per day and installation of instrument made on urgent basis.

Wapda spokesman was very brief while commenting on the development. He said, “Filling of water in the reservoir is being done in accordance with the SOP keeping in view the safety of the dam.”

IRSA and Punjab government have already expressed resentment over the slow filling of dam. A senior official of Punjab recalled that Wapda in different years, resorted to accelerated filling of Tarbela Dam in order to ensure storage to maximum level. In 2011, water filled in the lake at the rate of 4.5 feet per day to two feet per day between 1,520 and 1,540 feet, which made it possible to fill the dam in a very short span of time.

With this acceleration rate, the dam level rose to maximum level in just 20 days from 1,508 feet to 1,550 feet. However, he observed, now Wapda and others have decided to slow down the filling process to unprecedented level “due to reasons better known to them.”

“If we fail to store maximum possible water in Tarbela Dam in the surplus flow period, who will be responsible for loss of crops due to water shortage and other likely damages during the lean period,” he asked.