USGS Water-Year Summary 2021
10260855 Grass Valley Lake Tunnel Outlet at Lake Arrowhead, CA
LOCATION - Lat 34°15'36", long 117°12'16" referenced to North American Datum of 1983, in SW 1/4 NW 1/4 sec.16, T.2 N., R.3 W., San Bernardino County, CA, Hydrologic Unit 18090208, on left bank, 20 ft below outlet of tunnel connecting Grass Valley Lake and Lake Arrowhead, and 0.2 mi above Lake Arrowhead, in the town of Lake Arrowhead.
DRAINAGE AREA - Indeterminate.
PERIOD OF RECORD - October 2008 to current year.
GAGE - Water-stage recorder, crest-stage gage, and concrete control. Elevation of gage is 5,150 ft above NGVD of 1929, from topographic map.
EXTREMES FOR PERIOD OF RECORD - Maximum discharge, 82.1 ft³/s, Feb. 14, 2019, gage height, 3.38 ft, from rating curve extended above 19 ft³/s, on basis of critical-depth computations; no flow for some days each year.