USGS Water-Year Summary 2021
08206910 Choke Canyon Reservoir (Outlet Works Channel) near Three Rivers, TX
LOCATION - Lat 28°29'09", long 98°14'29" referenced to North American Datum of 1927, Live Oak County, TX, Hydrologic Unit 12110108, 0.2 mi downstream from Choke Canyon Dam on Frio River, 3.7 mi upstream from Atascosa River, and 3.8 mi west of Three Rivers.
DRAINAGE AREA - 5,490 mi².
PERIOD OF RECORD - Nov. 1991 to Sept. 1999 (daily mean discharges less than 73 ft³/s), Oct. 1999 to current year (daily mean discharges less than 1,130 ft³/s).
GAGE - Water-stage recorder. Datum of gage is 124.06 ft above NGVD of 1929. Satellite telemeter at station.
EXTREMES FOR PERIOD OF RECORD - Maximum gage height, about 38 ft (backwater), Sept. 11, 2002 (discharge not determined); no flow many days.