ISLAMABAD, Dec 24: The Indus River System Authority (Irsa) will start closing down canals on Wednesday for annual cleaning and maintenance, official sources said.

A senior government official said the canal closure that would last till Jan 31 would reduce the hydropower generation by more than 5,000mw, resulting in increased loadshedding.

An Irsa official said under the canal closure plan, the water regulator would reduce discharges from Mangla Dam to 10,000 cusec from the current outflows of about 25,000 cusec. Releases from Tarbela Dam would be scaled down to about 15,000 cusec from 20,000 cusec.

Minimum releases of 15,000 cusec from Tarbela and 10,000 cusec from Mangla were necessary to meet drinking water requirements, he said, adding 11 out of 14 power stations at Tarbela had already been turned off.

During the mandatory canal closure, electricity generation from hydropower sources drops to an average of 1000mw from its maximum capacity of about 6,700mw. Currently, loadshedding is taking place for 2-3 hours in urban areas and up to six hours in rural areas. It is anticipated to go up by another two hours.

Under the canal closure plan, Punjab’s Lower Jhelum Canal will remain closed from Dec 26 to Jan 12 and Thall Canal from Jan 13 to 30.

The canals originating from the head Tarimu will remain closed from Jan 10 to 27 and Sidhnai Canal from Jan 11 to 28. The canals from Punjnad will be closed between Jan 5 and 22 and those from Taunsa from Dec 31 to Jan 17. Kotri Barrage will remain closed from Dec 26 to Jan 10 and Sukkur Barrage from Jan 5 to Jan 20. The Chashma Right Bank Canal will remain closed from Jan 1 to 31.