USGS Water-Year Summary 2024

07021000 CASTOR RIVER AT ZALMA, MO

LOCATION - Lat 37°08'47.9", long 90°04'31.8" referenced to North American Datum of 1983, in SE 1/4 sec.29, T.29 N., R.9 E., Bollinger County, MO, Hydrologic Unit 07140107, on downstream side of left bridge pier on State Highway 51 in Zalma and 2.5 mi downstream from Perkins Creek.

DRAINAGE AREA - 423 mi².

REVISIONS HISTORY - WSP 1147: 1922-23(M). WSP 1281: Drainage area.

SURFACE-WATER RECORDS

PERIOD OF RECORD - Jan 1920 to Sep 1991, Nov 8, 2000 to current year. Prior to Oct 1921 monthly discharge only published in WSP 1311.

REVISED RECORDS - WSP 1147: 1922-23(M). WSP 1281: Drainage area.

GAGE - Water-stage recorder and crest-stage gage. Datum of gage is 350.49 ft above North American Vertical Datum of 1988. Jan 1920 to Oct 1, 1925, at site 500 ft upstream at datum 49.82 ft lower; Oct 1, 1925 to Nov 12, 1930, at site 500 ft upstream at datum 0.18 ft higher; Nov 13, 1930 to Jun 8, 1953, nonrecording gage at present site and datum; Jun 1953 to Sep 1991 and Oct 2000 to current year, water-stage recorder at present site and datum; Dec 18, 1949 to Sep 1991, auxiliary nonrecording gage 6.0 mi downstream; Oct 2000 to Jun 6, 2012, auxiliary water-stage recorder 6.0 mi downstream.

REMARKS - Accuracy of records is discussed in the annual Station Analysis archived at the USGS MO Water Science Center.  

EXTREMES OUTSIDE PERIOD OF RECORD - Flood of 1915 reached a stage of 28.0 ft, present datum, from floodmarks by local residents.