USGS Water-Year Summary 2019
07018100 BIG RIVER NEAR RICHWOODS, MO
LOCATION - Lat 38°09'34.6", long 90°42'21.8" referenced to North American Datum of 1983, in sec.33, T.40 N., R.3 E., Jefferson County, MO, Hydrologic Unit 07140104, on left bank on downstream side of bridge on State Highway H, 1.8 mi east of Fletcher, 6.8 mi east of Richwoods, and at mile 53.7.
DRAINAGE AREA - 735 mi².
PERIOD OF RECORD - Oct 1942 to current year. Prior to May 1949 monthly discharge only, published in WSP 1311. Prior to 1984 published as Big River near De Soto (07018000).
GAGE - Water-stage recorder and crest-stage gage. Datum of gage is 523.00 ft above National Geodetic Vertical Datum of 1929. Prior to Sep 30, 1983 at site 5.5 mi downstream at datum 15.79 ft higher.
EXTREMES OUTSIDE PERIOD OF RECORD - Flood of Aug 1915 reached a stage of about 29.4 ft (former datum), discharge, about 70,500 ft³/s, from rating curve extended above 37,000 ft³/s.
PERIOD OF RECORD - Aug 1963 to Jul 1975, Nov 1983 to Jun 1987, Nov 1992 to current year. Aug 1963 to Jul 1975 published as Big River near De Soto (07018000).