Fruitful weather? Power output increases by 100MW in Tarbela

Conservation level will reach maximum capacity of 1,550 feet by August 20

HARIPUR:

On-going wet spell in the catchment areas of Indus River has increased water flowing into Tarbela Dam, nearly filling it to a point sufficient enough for power units in the dam to generate more electricity.

Officials privy to the daily data of water inflow told The Express Tribune on Friday the reservoir was just 17 feet short of its maximum conservation level of 1,550 feet. However, this would be reached by August 20 which is the date when the reservoir fills to its maximum level every year, they added. Sources said the rate of flow of water was such that dam authorities had to open the spillways on July 20 to create space as heavy floods can enter the reservoir any time this week.

The decision to open the service and auxiliary spillways has been made to avoid any emergency situation that could harm the integrity of the dam’s structure. The spillways release 279,700 cusecs of water daily against an inflow of 363,000.

“Although rivers are already inundated and low-lying areas have been facing flash floods, we have to release extra water to create space for more water for the sake of the dam’s structure,” said an official. “The level was 1,533 feet Friday morning.”

Man-made

Tarbela is the country’s biggest man-made water body—97 kilometres in length.The dam was built in the late 60s after clearing over 100 villages in Haripur district and a few in Mansehra, Torghar and Swabi. It is the biggest source of hydel power generation and irrigation in the country.

The dam has three tunnels with 14 power units with a total capacity to generate 3,478 megawatts of electricity. A project for the fourth tunnel is under way with the support of USAID.

Power generation

The latest increase in water levels has helped power generation in all 14 units, increasing the capacity to 3,578MW— an extra 100MW.

Each of the first 10 units has the capacity of generating 175MW, in total 1750MW.  The remaining four units generate 432MW each. However, during peak days when the dam is filled to capacity, it can generate up to 3,800MW.

Published in The Express Tribune, July 25^th, 2015.