USGS Water-Year Summary 2023
08136600 O. H. Ivie Reservoir near Voss, TX
LOCATION - Lat 31°30'00", long 99°40'05" referenced to North American Datum of 1927, Coleman County, TX, Hydrologic Unit 12090106, on left bank, in outlet structure of Freese-Nichols Dam on Colorado River, 8.0 mi northeast of Millersview, 10.0 mi southwest of Voss, and at mile 615.1.
DRAINAGE AREA - 24,038 mi² of which 11,391 mi² probably is noncontributing.
- Datum of the gage has always been on a locally provided reservoir datum, but was previously referenced to NGVD of 1929 in error from 2015 to 2022 in NWIS web and possibly other data sources as well (e.g., Texas Water Development Board). Due to lack of information, a GNSS survey was completed at the station Feb. 25, 2021, and found the datum to be -0.03 ft. above NAVD88 and 0.28 ft. above NGVD29. To convert published elevation values to NAVD88, add 0.03 ft. To convert published elevation values to NGVD29 subtract 0.28 ft.
PERIOD OF RECORD - Sept. 1990 to Sept. 2003 (daily mean contents), Oct. 2003 to Sept. 2004 (daily mean elevation), Oct. 2004 to current year.
GAGE - Water-stage recorder. Datum of gage determined from Colorado River Municipal Water District survey point (local reservoir datum, vertical control unknown). Satellite telemeter at station. A GNSS RTK survey done on Feb. 25, 2021 found that to determine NAVD88 elevation values add 0.026 ft. to current elevations.
COOPERATION - Records of diversions may be obtained from the Colorado River Municipal Water District.
EXTREMES FOR PERIOD OF RECORD - Sept. 1990 to Sept. 2003, Oct. 2004 to current year: Maximum contents, 574,700 acre-ft, June 26, 1997; minimum contents after initial filling, 59,110 acre-ft, May 24, 2014; Sept. 1990 to current year: Maximum elevation, 1,552.55 ft, June 26, 1997; minimum elevation, 1,502.46 ft, May 24, 2014.