USGS Water-Year Summary 2020
09402500 COLORADO RIVER NEAR GRAND CANYON, AZ
LOCATION - Lat 36°06'05", long 112°05'08" referenced to North American Datum of 1927, in sec.05, T.31 N., R.3 E., Coconino County, AZ, Hydrologic Unit 15010001, in Grand Canyon National Park, on left bank 0.2 mi upstream from Kaibab Bridge, 0.4 mi upstream from Bright Angel Creek, 4.5 mi northeast of village of Grand Canyon, 26 mi downstream from Little Colorado River, and 267 mi upstream from Hoover Dam.
DRAINAGE AREA - 141,600 mi² of which 3,959 mi² probably is noncontributing. in the Great Divide basin in southern Wyoming.
PERIOD OF RECORD - Oct. 1922 to current year. Prior to 1944, published as "Colorado River at Bright Angel Creek, near Grand Canyon." Gage-height records collected 1.5 mi downstream 1908-1913, published in reports of U.S. Weather Bureau.
GAGE - Water-stage recorder. Datum of gage is 2,418.7 ft above sea level.
EXTREMES OUTSIDE PERIOD OF RECORD - Maximum discharge since at least 1884, 300,000 ft³/s about July 8, 1884 (computed on basis of flood studies at Lees Ferry). Crest discharge of flood of June 19, 1921, was 220,000 ft³/s, gage height, 37.5 ft from floodmarks, from rating curve extended above 120,000 ft³/s.
EXTREMES FOR PERIOD OF RECORD - 1922-1962: Maximum discharge, 127,000 ft³/s, July 2, 1927, gage height, 29.25 ft; minimum, 700 ft³/s Dec. 28, 1924, gage height, -0.70 ft.
1963-2017: Maximum discharge, 96,200 ft³/s, June 29, 1983, gage height, 26.26 ft; minimum, 850 ft³/s, Jan. 26, 1963, gage height, -0.55 ft, result of closing coffer dam at Glen Canyon Dam.