
Selected peak daily and instantaneous spring flood flows recorded at the USGS Pohono Bridge gage (Gage No. 11266500) on the Merced River. Note the difference between 1983's daily and instantaneous peaks.
Largest Flood on Record: Floods can happen due to peak spring melt or due to rain-on-snow events any time of the year. Yosemite's flood of record is 23.45 feet at Pohono Bridge, occurring Jan. 2, 1997, as a rain-on-snow event. Yosemite's records at Pohono Bridge and Happy Isles gage stations date back to 1916.
http://www.nps.gov/yose/naturescience/flooding.htm