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USGS Water-Year Summary 2024
13333000 GRANDE RONDE RIVER AT TROY, OR
LOCATION - Lat 45°56'45", long 117°27'00" referenced to North American Datum of 1927, in NE 1/4 NW 1/4 sec.04, T.5 N., R.43 E., Wallowa County, OR, Hydrologic Unit 17060106, on left bank, on upstream side of bridge at Troy, 100 ft downstream from Wenaha River and at mile 45.3.
DRAINAGE AREA - 3,275 mi².
REVISIONS HISTORY - WSP 1397: 1946(M), 1948-50.
SURFACE-WATER RECORDS
PERIOD OF RECORD - August 1944 to current year. Monthly discharge only, August 1944, published in WSP 1317.
GAGE - Water-stage recorder and crest-stage gage. Datum of gage is 1,585.98 ft above NGVD of 1929. Aug. 17, 1944 to Sept. 30, 1949, nonrecording gage at datum 10.85 ft lower. Oct. 1, 1949 to Sept. 5, 1963, water-stage recorder at datum 1.15 ft higher. Sept. 6, 1963 to Oct. 19, 1994, water-stage recorder at site 500 ft downstream at present datum.
REMARKS - Flow slightly regulated by Wallowa Lake and small reservoirs. Diversions for irrigation upstream from station, mainly in vicinity of LaGrande, Enterprise and Wallowa; transbasin diversions for irrigation from Big Sheep Creek and tributaries in Imnaha River Basin to Wallowa River Basin and from South Fork Catherine Creek to the Powder River Basin.
EXTREMES FOR PERIOD OF RECORD - Maximum discharge, 51,800 ft³/s Feb. 9, 1996, gage height, 13.76 ft, from rating curve extended above 20,000 ft³/s; minimum discharge, 321 ft³/s Nov. 25, 1993, result of freezeup, but may have been less during period of ice effect that day.
