USGS Water-Year Summary for Site 09213700

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	Available Parameters
	00054 Reservoir storage(Obs.)
	62614 Elevation, lake/res, NGVD29(Obs.)

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Water year 2023: 2022-10-01 to 2023-09-30

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USGS Water-Year Summary 2023

09213700 BIG SANDY RESERVOIR NEAR FARSON, WY

LOCATION - Lat 42°14'57", long 109°25'43" referenced to North American Datum of 1927, in NE 1/4 NW 1/4 NW 1/4 sec.11, T.26 N., R.106 W., Sweetwater County, WY, Hydrologic Unit 14040104, 20.5 mi upstream from Little Sandy Creek, and 10.1 mi north of Farson.

DRAINAGE AREA - 386 mi².

REVISIONS HISTORY - WDR WY-98-1: 1996, 1997.

SURFACE-WATER RECORDS

PERIOD OF RECORD - May 1987 to current year.

GAGE - Water-stage recorder. Elevation of gage is 6,770.00 ft above NGVD of 1929 (levels by U.S. Bureau of Reclamation). U.S. Geological Survey data collection platform with satellite telemetry at station.

REMARKS -

The reservoir is formed by an earth fill dam, with lowest elevation of the reservoir at 6,700.0
ft, storage began in April 1953. Total capacity, 64,692 acre-ft at elevation 6,767.5 ft, not
including 1,400 acre-ft of dead storage in a permanent pool at elevation 6,720.0 ft, trash rack sill. Concrete spillway
begins to release water when lake elevation reaches 6,762.5 ft. Spillway elevation was increased 5 feet during 2023
per US Bureau of Reclamation (USBR).  Old spillway elevation was 6,757.7 ft as modified in 2017 from previously reported elevations. 
Reservoir is used for storage of irrigation water and for recreation.

A capacity table (elevation, in feet, and contents, in acre-feet) follows:

Reservoir Elevation-Capacity Table

Elevation, in ft   Capacity, in acre-ft     Elevation, in ft   Capacity, in acre-ft
6,720.0            0                        6,750.0            22,175
6,730.0            2,695                    6,760.0            42,901
6,740.0            8,647                    6,767.5            64,692

EXTREMES FOR PERIOD OF RECORD - Maximum contents, 41,400 acre-ft, June 12, 1997 and July 2, 2011, at elevation 6,758.71 ft, June 12, 1997; Maximum elevation, 6758.91 ft. June 9, 2017, contents 40,120 acre-ft. Minimum contents, 12.6 acre-ft estimated, August 18, 2021, elevation 6,720.00 ft, from manual measurement during spillway repair operations.