The US Geological Survey maintains stream gages with realtime data along the Merced River just above and below Yosemite Valley. The following is from the NPS page, current last friday, but seems to be at variance with the comments people have been making.
Water levels are high with seasonal waterfalls flowing well.
The US Geological Survey maintains stream gages with realtime data along the Merced River just above and below Yosemite Valley.