Rawal Dam authorities opened the spillway of the reservoir on Saturday after the water level rose to alarming levels owing to heavy rains in the city and its suburbs.
Officials said water level of the dam had risen up to 1,772 feet after which spillways were opened at 8 in the morning and would remain open until the water level receded to 1,748 feet.
The purpose of opening the spillway is to create space for more rainwater as the Meteorological Department has forecast heavy rains in the next 72 hours.