USGS Water-Year Summary 2024
06442900 ELM CR NEAR GANN VALLEY SD
LOCATION - Lat 44°04'38.98", long 99°09'02.46" referenced to North American Datum of 1927, Buffalo County, SD, Hydrologic Unit 10140105, on the left bank upstream side of bridge on Hwy 34, 8.2 mi west of intersection of Hwy 34 and Hwy 45, and 14.3 mi east of Fort Thompson.
DRAINAGE AREA - 378 mi².
SURFACE-WATER RECORDS
PERIOD OF RECORD - October 1987 to September 1999 and October 2016 to current, (continuous-record gaging station). 1955-1960 (low-flow partial record).
GAGE - Water-stage recorder and crest-stage gage. Datum of gage is 1,601 ft above NAVD88. Datum was converted to NAVD88 datum using the National Geodetic Surveys VDATUM transformation tool. Prior to conversion to NAVD88 on Oct. 1, 2019 datum was published as 1,600 ft above NGVD29, from topographic map.
EXTREMES OUTSIDE PERIOD OF RECORD - Flood of Apr. 3, 1969, reached a stage of 20.00 ft, present datum, from floodmark, discharge not determined: information supplied by local farmer.
EXTREMES FOR PERIOD OF RECORD - Maximum discharge, 9,000 ft³/s (estimated), July 25, 1993, gage height, 17.24 ft; minimum daily discharge, 0.00 ft³/s, Oct. 1, 1987, no flow for some days in most years.