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Water-Year Summary for Site 09474000

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Available Parameters
00060 Discharge(Mean)  

Water year 2021: 2020-10-01 to 2021-09-30

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USGS Water-Year Summary 2021
LOCATION - Lat 33°06'10", long 110°58'33" referenced to North American Datum of 1927, in NE 1/4 NW 1/4 sec.12, T.4 S., R.13 E., Pinal County, AZ, Hydrologic Unit 15050100, on left bank at Kelvin, 500 ft downstream from Mineral Creek, 18 mi downstream from San Pedro River, and 19 mi upstream from Ashurst-Hayden Dam.
DRAINAGE AREA - 18,011 mi², 12,866 mi² being above Coolidge Dam, and 5,125 mi² below Coolidge Dam (696 mi² of this area are in Mexico)
PERIOD OF RECORD - Jan. 1911 to current year.
REVISED RECORDS - WSP 329: 1911. WSP 609: 1916(M). WSP 629: 1914-17. WSP 1119: 1913, 1915, 1917(M), 1921(M), 1922-23, 1927(M). WSP 1283: Drainage Area.
GAGE - Water-stage recorder. Datum of gage is 1,745.02 ft above sea level. Prior to June 15, 1914, and Dec. 1, 1914, to Aug. 31, 1915, nonrecording gages at several sites within 2 mi of present site at different datums. Sept. 1, 1915, to Sept. 30, 1963, water-stage recorder at site 900 ft downstream at datum 1.80 ft lower. Jan. 16, 1985, to June 1990, supplementary water-stage recorder at same site and datum.
REMARKS - Records fair. Large diversions above station for irrigation, of which about 90 percent is above Coolidge Dam. About 82,000 acres irrigated, a considerable portion by pumping from ground water. Flow regulated by San Carlos Reservoir 49 mi upstream since Nov. 15, 1928. (See sta 09469000.) San Pedro River contributes major portion of unregulated inflow.
EXTREMES FOR PERIOD OF RECORD - 1911-28: Maximum discharge, about 132,000 ft³/s, Jan. 20, 1916, gage height, 19.5 ft, site and datum then in use, from rating curve extended above slope-area measurement at gage height, 16.2 ft for flood of Sept. 28, 1926; minimum, no flow, Feb. 25, 1913. 1929-Current year: Maximum discharge, 100,000 ft³/s, Oct. 2, 1983, gage height, 33.0 ft from floodmark, from rating curve extended above 12,000 ft³/s on basis of peak discharge computed by step-backwater method at Hayden Railroad Bridge, 17.8 mi upstream, and by flood-routing; minimum daily, no flow for many days in most years.
AVERAGE DISCHARGE FOR PERIOD OF RECORD - (adjusted for storage in San Carlos Reservoir) 103 years, 490 ft³/s, 354,700 acre-ft/yr; median of yearly mean discharges, 296 ft³/s, 214,000 acre-ft/yr.
PERIOD OF RECORD - Dec. 1950 to Sept. 1994, Feb. 1996 to Feb. 1998, Sept. 2001 to June 2006 (discontinued).
PERIOD OF DAILY RECORD - SPECIFIC CONDUCTANCE:Oct. 1964 to Sept. 1976, Oct. 1996 to Feb. 1998. WATER TEMPERATURE:Dec. 1950 to Sept. 1976, Oct. 1996 to Feb. 1998. SUSPENDED-SEDIMENT DISCHARGE:Jan. 1958 to Sept. 1976.
REMARKS - No inflow from Mineral Creek between sampling point and gaging station except during infrequent periods of heavy local rains. Unpublished daily specific conductance measurements for period December 1950 to September 1964 available from the Arizona Water Science Center in Tucson, AZ.