A powerful earthquake originating in what seismologists call the Nankai Trough off the Pacific coast could cut off tap water to roughly 8.32 million people in Osaka, or 94 percent of the prefecture's residents, the Osaka Prefectural Government said Friday.

The outage would be caused by damage to tap water infrastructure stemming from the intense oscillation, tsunami and liquefaction, it said, quoting the conclusions of an advisory panel to the prefecture.

An intense temblor would cut power to a combined 2.34 million households (55 percent) in the prefecture, and gas to 1.15 million (34 percent), according to the prefectural government.