USGS Water-Year Summary 2024
09419800 Las Vegas Wash Below Lake Las Vegas Near Boulder City, NV
LOCATION - Lat 36°07'20", long 114°54'15" referenced to North American Datum of 1927, in NE 1/4 SE 1/4 sec.14, T.21 S., R.63 E., Clark County, NV, Hydrologic Unit 15010015, in Lake Mead Recreation Area, on right bank, under bridge at North Shore Road, and 11.0 mi north-northwest of Boulder City.
DRAINAGE AREA - 2,193 mi² of which 607 mi² probably is noncontributing.
REVISIONS HISTORY - Discharge measurement number 582, made on Aug. 1, 2019 was revised based on a reanalysis of the extrapolation for the measurement on Aug. 22, 2019. Maximum discharge for water year 2020 was revised on Nov 10, 2020, based on changes to the stage discharge rating and new information at the upstream site.
SURFACE-WATER RECORDS
PERIOD OF RECORD - Aug. 1969 to Sep. 1984, Jul. 2002 to current year.
GAGE - Datum of gage is 1249.45 ft above NAVD of 1988. The NAVD of 1988 datum was determined by a level 2 GNSS survey (Reference Frame NAD_83 (2011) (EPOCH:2010.0000), GEOID18) by USGS on February 10, 2020 and tied to TRM. Prior to February 10, 2020, the gage datum was 1280 ft above NGVD of 1929 as determined via topographic map by USGS on August 6, 1969. Prior to June 5, 1978, water-stage recorder at site 50 ft upstream at different datum.
EXTREMES FOR PERIOD OF RECORD - Maximum discharge, 10,900 ft³/s, Mar. 12, 2020, gage height, 12.52 ft, from slope-area measurement of peak flow; minimum daily, 17 ft³/s, Jul. 8, 30, 1971.
WATER-QUALITY RECORDS
PERIOD OF RECORD - Jan. 1964 to Jan. 1965, Sep. 1966 to Feb. 1986, Nov. 2001 to Aug. 2002, May to Sep. 2004.
PERIOD OF DAILY RECORD -
SPECIFIC CONDUCTANCE: Jun. 1975 to Mar. 1976, Nov. 1976 to Apr. 1978, and Aug. 1979 to Feb. 1986.
WATER TEMPERATURE:Nov. 1979 to February 1986.
EXTREMES FOR PERIOD OF DAILY RECORD -
SPECIFIC CONDUCTANCE: Maximum daily, 6,140 microsiemens/cm Feb. 7, 1976; minimum daily, 1,390 microsiemens/cm Jul. 7, 1985.
WATER TEMPERATURE: Maximum, 30.5°C Jul. 11, 12, 1985; minimum, 7.5°C February 8, 1982, Jan. 19, 21, 1984.