Water-Data Report 2013 11234700 Mammoth Pool Reservoir near Big Creek, CA Basin

LOCATION.--Lat 37°19′40″, long 119°19′38″ referenced to North American Datum of 1927, in SE ¼ SE ¼ sec.10, T.7 S., R.24 E., Madera County, CA, Hydrologic Unit 18040006, in , in gatehouse of power tunnel intake, 0.7 mi northwest of dam on San Joaquin River, and 9.0 mi northwest of town of Big Creek. DRAINAGE AREA.--995 mi².

SURFACE-WATER RECORDS PERIOD OF RECORD.--October 1959 to current year. GAGE.--Water-stage recorder. Elevation of gage is 3,354.28 ft above NGVD of 1929 (levels by Southern Edison Co.). COOPERATION.--Records were collected by Southern California Edison Co., under general supervision of the U.S. Geological Survey, in connection with Federal Energy Regulatory Commission project no. 2085. Records not rounded to U.S. Geological Survey standards. REMARKS.--Reservoir is formed by an earth-fill dam; storage began Oct. 8, 1959. Usable capacity, 119,940 acre-ft, between elevations 3,100.00 ft, invert of power tunnel, and 3,330.00 ft, crest of spillway. Additional storage of 2,780 acre-ft is not available for release. Water is diverted from Mammoth Pool through tunnel for power development and returned to river 8.5 mi downstream from dam. Records, excluding extremes, represent usable contents at 2400 hours. See schematic diagram of lower San Joaquin River Basin available from the California Water Science Center. EXTREMES FOR PERIOD OF RECORD.--Maximum contents, 128,944 acre-ft, Jan. 2, 1997, elevation, 3,338.00 ft; minimum contents since appreciable storage was attained, 1,134 acre-ft, Sept. 25, 1992, elevation, 3,112.82 ft. EXTREMES FOR CURRENT YEAR.--Maximum contents, 121,328 acre-ft, May 4, elevation, 3,331.25; minimum, 4,972 acre-ft, Sept. 29, elevation, 3,142.20 ft.

Capacity table (elevation, in feet, and contents, in acre-feet) (Based on table provided by Southern California Edison Co., dated Nov. 6, 1959) Elevation Contents Elevation Contents Elevation Contents Elevation Contents 3,100 0 3,130 3,114 3,180 14,060 3,260 56,381 3,105 417 3,140 4,605 3,190 17,414 3,280 72,109 3,110 861 3,150 6,402 3,200 21,400 3,300 89,781 3,115 1,355 3,160 8,618 3,220 31,109 3,320 109,336 3,120 1,900 3,170 11,165 3,240 42,787 3,340 131,255

U.S. Department of the Interior Suggested citation: U.S. Geological Survey, 2014, Water-resources data for the United States, Water U.S. Geological Survey Year 2013: U.S. Geological Survey Water-Data Report WDR-US-2013, site 11234700, accessed at http://wdr.water.usgs.gov/wy2013/pdfs/11234700.2013.pdf Water-Data Report 2013 11234700 Mammoth Pool Reservoir near Big Creek, CA—Continued

RESERVOIR STORAGE, ACRE FEET WATER YEAR OCTOBER 2012 TO SEPTEMBER 2013 DAILY OBSERVATION AT 2400 HOURS [e, estimated] Day Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep

1 7,582 13,418 23,226 30,272 42,392 42,467 86,072 120,875 116,503 98,402 49,728 8,948 2 7,646 13,633 30,940 30,821 42,361 42,838 87,517 120,657 117,619 96,404 48,426 8,540 3 7,727 13,828 36,040 31,664 42,474 43,658 88,585 121,071 118,367 94,295 47,453 8,198 4 7,833 14,031 38,391 32,468 42,429 44,267 90,692 120,820 118,262 92,221 46,764 7,829 5 8,013 14,188 39,983 33,274 42,768 44,826 92,718 120,170 118,050 90,286 46,712 7,763 6 8,198 13,418 41,494 34,076 42,586 45,466 94,486 119,537 117,494 89,016 e46,869 7,261 7 8,371 13,394 42,632 34,841 41,903 46,085 96,495 e118,575 116,695 88,207 46,673 6,740 8 8,549 13,313 43,469 35,676 41,355 46,587 98,468 117,390 116,081 87,006 45,396 6,161 9 8,731 13,182 44,256 36,518 40,621 47,234 99,052 116,188 115,490 84,851 44,498 6,084 10 8,881 12,822 44,757 37,534 40,131 47,637 99,374 115,638 114,847 82,670 43,972 6,251 11 9,065 12,445 45,338 38,286 40,522 48,256 99,718 116,131 113,910 81,312 43,282 6,406 12 9,237 11,749 45,898 39,063 39,595 49,037 100,487 117,105 112,659 79,405 42,335 6,565 13 9,423 10,704 46,328 39,803 38,669 50,049 102,274 118,248 111,550 77,393 40,947 6,721 14 9,601 10,478 46,869 39,080 38,886 51,359 104,035 119,741 109,649 76,063 39,439 6,871 15 9,780 10,334 47,242 38,881 39,109 53,391 105,351 120,528 108,015 75,156 37,195 7,020 16 9,932 10,540 47,559 38,736 39,467 55,780 105,714 120,643 106,377 74,483 34,740 7,166 17 10,074 11,122 48,204 38,597 39,850 58,343 104,456 119,829 105,693 e73,547 32,858 7,305 18 10,239 12,238 48,284 38,273 40,129 60,323 103,001 118,882 104,719 72,336 30,403 7,439 19 10,368 12,864 47,215 38,129 40,582 61,890 101,396 118,140 103,869 71,467 28,515 7,588 20 10,504 13,324 45,902 37,847 40,956 64,155 101,933 117,283 102,951 70,420 26,944 7,736 21 10,659 13,777 44,285 37,978 41,042 66,139 102,960 116,784 102,175 69,440 24,555 7,912 22 10,895 14,280 43,071 37,859 41,191 67,986 105,016 117,205 101,611 67,862 22,209 8,203 23 11,275 14,768 42,459 37,763 41,512 69,671 107,020 116,599 101,247 65,654 20,378 8,488 24 11,531 15,214 42,710 38,373 41,768 71,510 108,545 115,402 100,913 63,891 18,778 8,573 25 11,765 15,648 41,143 39,351 42,111 73,695 109,538 114,505 100,907 61,748 16,595 7,568 26 11,992 16,079 40,209 40,391 42,380 75,652 110,112 113,832 100,950 59,397 14,493 6,287 27 12,234 16,439 39,194 41,308 42,587 77,325 111,230 112,845 100,785 57,542 12,946 5,576 28 12,495 16,880 37,228 41,581 42,656 79,038 113,659 112,081 100,521 55,951 11,815 4,974 29 12,731 17,635 35,444 41,786 --- 80,724 116,248 113,368 100,247 54,176 10,826 5,151 30 12,954 20,937 33,776 42,023 --- 82,214 119,188 114,618 100,004 52,224 9,974 5,382 31 13,192 --- 32,205 42,067 --- 84,375 --- 115,596 --- 50,521 9,409 --- Max 13,192 20,937 48,284 42,067 42,768 84,375 119,188 121,071 118,367 98,402 49,728 8,948 Min 7,582 10,334 23,226 30,272 38,669 42,467 86,072 112,081 100,004 50,521 9,409 4,974 Elevation, in feet, at end of month 3,177.14 3,198.91 3,222.01 3,238.85 3,239.79 3,294.10 3,329.31 3,325.97 3,310.74 3,251.75 3,163.23 3,144.55 Change in contents, in acre-feet +5,590 +7,745 +11,268 +9,862 +589 +41,719 +34,813 -3,592 -15,592 -49,483 -41,112 -4,027

Calendar Year 2012 Water Year 2013 Change in contents, in acre-feet -13,979 -2,220

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140,000

120,000

100,000

80,000

STORAGE, ACRE , FEET ACRE STORAGE, 60,000 OBSERVATION AT 2400 HOURS RESERVOIR 40,000

20,000

0 O N D J F M A M J J A S 2012 2013

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