Water-Data Report 2007 11313500 Salt Springs Reservoir near West Point, CA San Joaquin River Basin

LOCATION.--Lat 38°29′55″, long 120°12′52″ referenced to North American Datum of 1927, in NW ¼ SE ¼ sec.33, T.8 N., R.16 E., Calaveras County, CA, Hydrologic Unit 18040012, in , near center of Salt Springs on North Fork , 1.8 mi upstream from Cole Creek, and 18 mi northeast of West Point. DRAINAGE AREA.--169 mi². SURFACE-WATER RECORDS PERIOD OF RECORD.--March 1931 to current year. Prior to October 1964, records published as usable contents. REVISED RECORDS.--WSP 1930: Drainage area, WDR CA-00-3: 1999 (month-end gage heights). GAGE.--Water-stage recorder. Prior to Oct. 1, 1991, nonrecording gage read once daily. Datum of gage is NGVD of 1929 (levels by Pacific Gas and Electric Company). COOPERATION.--Records were collected by Pacific Gas and Electric Company, under general supervision of the U.S. Geological Survey, in connection with Federal Energy Regulatory Commission project no. 137. REMARKS.--Reservoir is formed by concrete-faced rock-fill dam, completed in 1931; storage began in March 1931. Capacity, 141,857 acre-ft, between elevations 3,667.75 ft, outlet drain, and 3,958.0 ft, top of radial gates. Storage of 1,860 acre-ft available for release to river only. Water is released through Salt Springs Powerplant (station 11313510) just downstream from dam and discharged into Tiger Creek Powerplant Conduit (station 11314000). Figures given, including extremes, represent total contents. See schematic diagram of Mokelumne River Basin available from the Water Science Center. EXTREMES FOR PERIOD OF RECORD.--Maximum contents, 142,208 acre-ft, June 22, 1999, elevation, 3,958.36 ft; no contents at times in 1932-33, 1945, 1962. EXTREMES FOR CURRENT YEAR.--Maximum contents, 120,000 acre-ft, May 30 to June 2, maximum elevation, 3,934.66 ft, May 31; minimum, 6,680 acre-ft, Feb. 3, elevation, 3737.08.

Capacity table (elevation, in feet, and contents, in acre-feet) (Based on table provided by Pacific Gas and Electric Company, dated October 1964) (REVISED) Elevation Contents Elevation Contents Elevation Contents Elevation Contents 3,700 1,251 3,735 6,230 3,760 12,690 3,850 54,852 3,710 2,199 3,740 7,324 3,780 19,632 3,900 90,786 3,720 3,519 3,750 9,799 3,800 28,017 3,960 143,788 3,730 5,229

U.S. Department of the Interior U.S. Geological Survey Water-Data Report 2007 11313500 Salt Springs Reservoir near West Point, CA—Continued

RESERVOIR STORAGE, ACRE FEET WATER YEAR OCTOBER 2006 TO SEPTEMBER 2007 DAILY OBSERVATION AT 2400 HOURS Day Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep

1 73,000 48,300 27,200 12,000 6,770 9,580 33,800 76,600 120,000 109,000 95,500 78,600 2 72,100 48,200 26,400 11,500 6,740 9,640 35,000 79,000 120,000 109,000 94,800 78,100 3 71,200 48,200 25,600 10,800 6,680 9,710 36,600 80,500 119,000 108,000 94,100 77,600 4 70,200 48,200 24,800 11,300 6,700 9,770 38,000 81,800 119,000 108,000 93,500 77,200 5 69,400 48,200 24,000 11,200 6,760 9,830 39,600 82,900 119,000 108,000 92,900 76,700 6 68,500 47,800 23,400 10,700 6,820 10,000 41,400 83,700 119,000 107,000 92,300 76,200 7 67,500 46,800 22,800 10,400 6,830 10,200 43,400 84,900 119,000 107,000 91,700 75,700 8 66,600 45,800 22,100 10,100 6,810 10,600 45,600 86,700 118,000 106,000 91,100 75,100 9 65,700 44,800 21,600 10,000 7,020 11,100 47,400 88,900 117,000 106,000 90,300 74,500 10 64,800 43,800 21,100 9,830 7,980 11,500 49,300 91,800 117,000 106,000 89,700 74,100 11 63,800 42,900 20,500 9,770 9,200 11,900 50,700 94,600 117,000 105,000 89,200 73,600 12 63,000 41,900 20,000 9,570 9,580 12,600 51,900 97,200 117,000 105,000 88,600 73,300 13 62,100 41,100 19,700 9,400 9,750 13,400 52,800 99,400 116,000 105,000 88,000 72,600 14 61,200 41,800 19,400 9,290 9,960 14,400 53,800 101,000 116,000 104,000 87,400 72,000 15 60,200 41,000 19,200 9,100 10,100 15,500 54,600 104,000 116,000 104,000 86,900 71,300 16 59,300 40,200 19,100 8,920 10,400 16,600 55,500 106,000 116,000 103,000 86,300 70,700 17 58,500 39,300 18,800 9,050 10,500 17,900 56,200 109,000 115,000 103,000 85,700 70,000 18 57,600 38,400 18,400 8,870 10,800 19,400 57,100 110,000 115,000 103,000 85,200 69,700 19 56,800 37,700 17,800 8,320 11,100 20,800 57,800 111,000 115,000 103,000 84,700 69,400 20 55,900 36,800 17,200 8,070 11,100 22,000 58,300 113,000 114,000 103,000 84,100 69,000 21 55,000 35,800 16,900 7,800 11,000 23,000 58,700 114,000 114,000 102,000 83,500 68,200 22 54,000 34,800 16,500 7,440 10,500 23,800 59,800 115,000 113,000 102,000 83,000 67,100 23 53,100 34,100 16,000 7,120 9,970 24,700 60,400 116,000 113,000 101,000 82,600 66,300 24 52,200 33,100 15,500 7,090 9,540 25,700 61,500 117,000 113,000 100,000 81,900 65,600 25 51,300 32,200 15,000 7,060 9,330 27,000 62,600 117,000 112,000 99,900 81,300 65,000 26 50,400 31,400 14,700 7,030 9,280 28,500 64,000 118,000 112,000 99,300 80,800 64,300 27 49,600 30,600 14,500 7,000 9,370 29,600 65,800 117,000 111,000 98,900 80,200 64,100 28 48,600 29,800 14,300 6,960 9,590 30,300 68,200 118,000 111,000 98,300 80,100 63,400 29 48,500 28,900 13,900 6,920 --- 31,100 70,900 119,000 110,000 97,700 79,900 63,400 30 48,500 28,100 13,300 6,880 --- 31,800 73,700 120,000 110,000 97,100 79,400 63,400 31 48,400 --- 12,800 6,830 --- 32,700 --- 120,000 --- 96,300 79,000 --- Max 73,000 48,300 27,200 12,000 11,100 32,700 73,700 120,000 120,000 109,000 95,500 78,600 Min 48,400 28,100 12,800 6,830 6,680 9,580 33,800 76,600 110,000 96,300 79,000 63,400 Elevation, in feet, at end of month 3,839.45 3,800.27 3,760.20 3,737.75 3,749.19 3,809.97 3,877.63 3,934.66 3,922.87 3,906.86 3,884.80 3,863.08 Change in contents, in acre-feet -25,600 -20,300 -15,300 -5,970 +2,760 +23,110 +41,000 +46,300 -10,000 -13,700 -17,300 -15,600 Release, in acre-feet, through Salt Springs Powerplant 123 3,160 12,240 6,630 111 123 119 7,450 371 12,140 9,400 7,620

Calendar Year 2006 Water Year 2007 Max 141,000 120,000 Min 12,800 6,680 Change in contents, in acre-feet -52,000 -10,600 Release, in acre-feet, through Salt Springs Powerplant 123,700 59,490

— 2 — Water-Data Report 2007 11313500 Salt Springs Reservoir near West Point, CA—Continued

120,000

100,000

80,000

60,000

40,000 OBSERVATION AT 2400 HOURS RESERVOIR STORAGE, ACRE FEET, RESERVOIR STORAGE, ACRE

20,000

0 O N D J F M A M J J A S 2006 2007

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