USGS Water-Year Summary 2018
12453700 COLUMBIA RIVER AT ROCKY REACH DAM, WA
LOCATION - Lat 47°31'28", long 120°18'04" referenced to North American Datum of 1927, in SW 1/4 NW 1/4 sec.02, T.23 N., R.20 E., Chelan County, WA, Hydrologic Unit 17020010, on right bank 0.5 mi downstream from Rocky Reach Dam, 1.5 mi downstream from Swakane Creek, 7.4 mi north of Wenatchee, and at mile 473.4. Auxiliary GAGE: Lat 47°31'30", long 120°18'00", in SE 1/4 sec. 10, T. 23 N., R. 20 E., on right bank 2.2 mi downstream from Rocky Reach Dam, 4.8 mi north of Wenatchee(Both gages are currently abandoned).
DRAINAGE AREA - 87,800 mi².
PERIOD OF RECORD - October 1960 to current year.
GAGE - Daily discharge determined from flow through turbines plus spillway flow when present. Datum of gage is NGVD of 1929. Oct. 1, 1960, to July 22, 1988, water-stage recorder with auxiliary water-stage recorder 1.9 mi downstream from base gage at same datum.
COOPERATION - Discharge records provided by Public Utility District No. 1 of Chelan County at Rocky Reach Dam through the Corps of Engineers, North Pacific Division, Reservoir Control Center. The U.S. Geological Survey makes discharge measurements at this site during the year.
EXTREMES FOR PERIOD OF RECORD - Maximum discharge, about 535,000 ft³/s, June 10, 1961, elevation, about 635.50 ft; minimum daily discharge, 25,100 ft³/s, Nov. 11, 1973.