USGS Water-Year Summary 2018
13039500 HENRYS FORK NEAR LAKE, ID
LOCATION - Lat 44°35'40", long 111°20'59" referenced to North American Datum of 1983, in NE 1/4 SW 1/4 sec.26, T.15 N., R.43 E., Fremont County, ID, Hydrologic Unit 17040202, Big Springs quad., on left bank 0.2 mi downstream from Henrys Lake Dam, 5.4 mi south of former Lake Post Office, and at mile 117.1. Beware of grizzly bear activity at this site.
DRAINAGE AREA - 94.6 mi². including 6.2 mi² of Dry Creek basin.
PERIOD OF RECORD - May 1920 to current year (prior to October 1929, irrigation seasons only). Monthly discharge only for some periods, published in WSP 1317.
GAGE - Water-stage recorder and crest-stage gage. Elevation of gage datum is 6,437.06 ft above NGVD of 1929, U.S. Army Corps of Engineers benchmark (levels by Bureau of Reclamation). May 1920 to September 1922, non recording gage at site 3 mi downstream and below mouth of Dry Creek at different datum. September 1922 to July 30, 1978, recording gage at site 140 ft upstream at different datum. July 31, 1978 to July 27, 1989, at present site at datum 4.0 ft higher.
EXTREMES OUTSIDE PERIOD OF RECORD - Outflow from Henrys Lake was reported to have ceased entirely in late summer of 1889.
EXTREMES FOR PERIOD OF RECORD - Maximum discharge, 907 ft³/s June 13, 1926, gage height, 5.40 ft, site and datum then in use; maximum gage height, 6.35 ft, Aug. 2, 2014; no flow for part of each day Sept. 17, 18, 1952, Sept. 5, 7-30, Oct. 1, 2, 1966, Sept. 18 to Oct. 6, 1977, Mar. 17, 2005.