LAHORE, Aug 6: The Chashma Barrage will have lost its reservoir 30 years from now because of sedimentation. Briefing a group of journalists from Lahore, project director Shahdin said that Chashma would not be used as a reservoir after 30 years. However, he added, power generation and other operations may continue on run-of-the-river basis.

This underlined the need for new reservoirs to overcome the persistent water shortage in the country, he observed. He said that the inflow at Chashma had declined significantly this year. As much as 250,000 cusecs of water was flowing in around this time of the year 2003, he recalled.

Mr Din said a plan was on the cards to irrigate some 265,000 acres in Dera Ismail Khan through a project on the Chashma Right Bank Canal. Chashma, the third major water reservoir after Tarbela and Mangla, has lost 50 per cent of its storage capacity since its establishment in 1971. Its storage capacity has gone down from 0.87MAF to 0.435MAF.

The Chashma Barrage is the highest of the six river structures provided under the Indus Basin Project. Located on the Indus some 56km downstream Jinnah Barrage, near the Kalabagh Town, the reservoir is spread over 139 square miles.

As much as 98,052 acres of land was acquired for Chashma, and Wapda paid Rs73.23 million to the affected people as compensation. The total cost of the project amounted to Rs399 million.

The major purpose of the 52-gate barrage is to supply water to the Chashma-Jhelum Link Canal and the Chashma Right Bank Canal. The link canal takes off from the left bank of the Chashma Barrage and connects it to the Jhelum river, supplying water for the canals taking off at Trimmu Headworks.

The barrage has the capacity to handle a maximum flood discharge of 950,000 cusecs besides generating 184 megawatts of electricity through eight bulb-type turbine units of 23 megawatts each. These turbines, installed for the first time in Pakistan, generate an average of 1,081 million kilowatt-hours annually.

The Chashma reservoir has a shallow eutrophic lake and adequate natural fish food. The types of fish being cultured include Rahu, Mori, Silver, Gross Corp and Gulfam. Superintendent-Engineer Malik Manzoor said Wapda had earned Rs142 million from Chashma fisheries since 1979. Some 17,022 metric tons of fish had been caught during this period.

Officials said that reduction of water storage capacity would also affect fish production at the barrage. It is pertinent to mention here that Chashma's fish resources have already been affected by polluted water from factories that discharge waste without treatment, and the trend needs to be checked to save Chashma's marine life.