Naltar hydel power plant: ‘Silt deposit in reservoir caused cracks in walls’

Floods 2010 to be blamed for 300,000 cusec feet of silt and mud accumulated inside the water reservoir.

Our Correspondent February 09, 2012


Authorities in Gilgit on Wednesday blamed last year’s floods for silt deposit in the water reservoir of the region’s biggest power generation unit which caused fissures in its walls and said the problem would be fixed with the help of experts over the next few days.

“Because of the floods that swept the region in 2010, more than 300,000 cusec feet of silt and mud had accumulated inside the water reservoir,” Secretary Water and Power Gilgit-Baltistan Ghulam Mehdi told reporters on Wednesday. He said the silt deposit had caused the walls to crack.

He briefed the media at a time when the water and power department was under attack for its failure to provide electricity to the regional capital.

Gilgit has experienced prolonged power outages since the reservoir’s walls were damaged as water supply to Naltar hydel power plant was cut off.

There was no electricity in Gilgit for over five days in January despite the fact that the region has a potential of producing over 45000 megawatts of power.

Mehdi said two small dams would be constructed near the water reservoir to ensure uninterrupted water supply to the hydel power project even in winters.

Naltar hydel power project produces 18 MW in summers when there is sufficient water supply.

“There is no truth in it,” he said, dispelling fears that the tank could burst due to pressure from the water and fissures in the walls.

The secretary said it would take two weeks to drain the water reservoir and remove the silt.

The city will still get electricity for eight hours every day during this period.

Mehdi rejected the impression that the material used in the construction of the reservoir was substandard. He said weather conditions did affect the reservoir’s structure which would be repaired after engaging technical experts experienced in construction of large dams. Replying to a question, he said the worms found inside the reservoir had nothing to do with the cracks.

Published in The Express Tribune, February 9th, 2012.


Most Read


SHEHZAD | 9 years ago | Reply

Gilgit city has plunged into darkness for two times now due to stoppage of 18 MW Nalter hydropower project. The first time we were told that worms have eaten up the sealant in control and expansion joints. Experts were called in to assess the problem and solve it by filling the joints. Not a month has passed since then that the power plant has again been shut down to repair the water leakage for the storage pond. This time Mehdi (Secretary W & P Deptt) has retracted earlier blame on worms and come up with even more preposterous argument that it is the silt that has caused water leakage. It is to inform Mr. Mehdi that silt cannot cause water leakage. Water from the pond floor or walls can leak due to one or more than one of the following three reasons: 1. Through concrete which alone is rarely adequate to ensure water proofing. Water can migrate through its microscopic pores or other pathways created by shrinking cracks. 2. Expansion joints and control joints. 3. Any instrument, utility or other penetration It is evident that adequate water proofing materials and techniques have not been employed. The Secretary should explore the application of bituminous membranes combined with resins and rubber and water stoppers to achieve full water proofing in the pond.

SHEHZAD | 9 years ago | Reply


The cracks in the dam structure were result of worms as per the previous assessment by W&P engineers and consultants. Now Mehdi is retracting the worm issue and presenting a new theory - silt in the dam. I think Mehdi is again wrong. silt cannot cause water leakage.

They should investigate on the following lines:

Water may be leaking from concrete through pores. It can be mitigated by installing a water proofing lining - bitumen sheets ( In saudia we have M/S Dermabit producing this water proofing material) Water may be leaking from control and expansion joins in grade slabs. The joints can be filled with suitable material to stop leakage.

Mehdi seems to be holding weather conditions responsible for the leakage which is totally disgusting. The concrete structures and materials should have been designed and specified for the application under real conditions of temperature etc.

This kind of incompetency, uselessness on behalf of Mehdi ( Secretary W & P) is really disturbing.

Replying to X

Comments are moderated and generally will be posted if they are on-topic and not abusive.

For more information, please see our Comments FAQ