USGS Water-Year Summary 2020
06482020 BIG SIOUX RIVER AT NORTH CLIFF AVENUE, AT SIOUX FALLS, SD
LOCATION - Lat 43°34'01.3", long 96°42'39.6" referenced to North American Datum of 1927, in SW 1/4 NW 1/4 sec.10, T.101 N., R.49 W., Minnehaha County, SD, Hydrologic Unit 10170203, on right bank 20 ft downstream from bridge on North Cliff Avenue and 4.1 mi upstream from Slip Up Creek.
DRAINAGE AREA - 4,662 mi² of which 884 mi² probably is noncontributing. documented runoff occurred during 1994-2002 water years for 213 mi² of the usually noncontributing area.
- WDR SD-10-1: Drainage area.
PERIOD OF RECORD - March 1962 to September 1971 (gage heights and discharge measurements only in files of U.S. Army Corps of Engineers). October 1971 to current year.
GAGE - Water-stage recorder. Datum of gage is 1,295.08 ft above NAVD88. Prior to conversion to NAVD88 datum was published as 1,294.18 ft above NGVD29 (levels by U.S. Army Corps of Engineers). Prior to Dec. 15, 1971, non-recording gage 20 ft upstream at datum 1,294.18 ft above NGVD29.
EXTREMES OUTSIDE PERIOD OF RECORD - Flood of Apr. 10, 1969, reached a stage of 27.45 ft, discharge, 40,700 ft³/s.