Hagibis typhoon: 19 dead as Japan launches major rescue
Public broadcaster NHK said 14 rivers across the nation had flooded, some spilling out in more than one spot.
A stretch of Fukushima, in the city of Date, was also flooded with only rooftops of residential homes visible in some areas, and rescuers paddled in boats to get people out. Parts of nearby Miyagi prefecture were also under water.
The Tama River, which runs by Tokyo, overflowed its banks, flooding homes and other buildings in the area.
Risk of mudslides
Boats as well as helicopters were sent to the flooded areas, while rescue crew dug through dirt elsewhere to try to get people out from homes buried by landslides.
Several train service in the Tokyo area resumed early morning, although others were undergoing safety checks and were expected to restart later Sunday.
He acknowledged Japan's power grids need to be strengthened so people in disaster areas can rely on timely information.