USGS Water-Year Summary 2021
14128870 COLUMBIA RIVER BELOW BONNEVILLE DAM, OR
LOCATION - Lat 45°37'59", long 121°57'39" referenced to North American Datum of 1983, in SW 1/4 SW 1/4 sec.21, T.2 N., R.7 E., Multnomah County, OR, Hydrologic Unit 17080001, on left bank, 0.9 mi downstream from Bonneville Dam left bank powerhouse, 50 ft upstream from Tanner Creek and at mile 144.5.
DRAINAGE AREA - 239,900 mi². approximately.
PERIOD OF RECORD - May 1981 to current year (gage heights only).
GAGE - Water-stage recorder and crest-stage gage. Datum of gage is NGVD of 1929. Prior to Aug. 15, 1990, at site 0.5 mi upstream at same datum.
EXTREMES FOR PERIOD OF RECORD - Maximum gage height, 35.11 ft Feb. 9, 1996; minimum, 6.06 ft Sept. 21, 2003.