An official of the Small Dams Organisation told Dawn that this year the spillways were opened much earlier because of early monsoon rains.
He urged the people residing along the Kurang Nullah to refrain from fishing and bathing in the downstream because of the release of large amount of water from the lake as it could be dangerous these days.
The official said they had arranged blowing of sirens before opening the spillways to warn the people to stay away from lake’s downstream nullah.
The current monsoon spell has considerably augmented the water level of Khanpur, Rawal and Simly dams, ensuring adequate water supply to Rawalpindi and Islamabad for the next six months.
Rain on Friday night which lasted till Saturday morning, raised the water level of Khanpur dam lake to 1,965 feet increasing the storage capacity by 18 feet.
As the Met Office has predicted above normal monsoon rainfall this year, the Khanpur dam administration expects the lake will fill to the optimum level in the second half of August.
According to Khanpur Dam’s executive engineer, Asim Rauf Khan, the inflow of water to the dam was recorded at 733 cubic feet per second (375 million gallons of water per day) on Saturday while the outflow to the canal supply was 58.18 cubic feet per second (28 million gallons of water per day).
The low outflow is mainly due to reduced water requirements for irrigation purposes in areas around Taxila tehsil.
The supply of water for municipal purposes to Rawalpindi and Islamabad was 55.18 cubic feet per second (25 million gallons of water per day). Municipal water consumption has also reduced during monsoon season.
Spillways of Khanpur Dam will be opened when water level would rise to 1,982 feet. The Khanpur Dam administration has already taken precautionary measures when spillways would be opened.
As the water level is rising each day, it has informed the Union Council, Police, non-governmental organizations and the downstream population to take precautionary measures.
Asim Rauf Khan told Dawn that a pre-feasibility study for the construction of a carry-over dam upstream Khanpur dam has been submitted to Planning and Investigating Department of Wapda.