11234700  MAMMOTH POOL RESERVOIR NEAR BIG CREEK, CA

LOCATION.--Lat 37°19'40", long 119°19'38", in SE 1/4 SE 1/4 sec.10, T.7 S., R.24 E., Madera County, Hydrologic
   Unit 18040006, Sierra National Forest, in gatehouse of power tunnel intake 0.7 mi northwest of dam on San
   Joaquin River, 9.0 mi northwest of town of Big Creek.
DRAINAGE AREA.--995 mi2.

PERIOD OF RECORD.--October 1959 to current year.
GAGE.--Water-stage recorder.  Datum of gage is sea level (levels by Southern California Edison Co.).

REMARKS.--Reservoir is formed by an earthfill 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 basin through Ward Tunnel
   (stations 11229500 and 11235500).  Water is diverted from Mammoth Pool through tunnel for power development
   and returned to river 8.5 mi downstream from dam.  Records, including extremes, represent usable contents
   at 2400 hours.  See schematic diagram of lower San Joaquin River basin.
COOPERATION.--Records were collected by Southern California Edison Co., under general supervision of the
   U.S. Geological Survey, in connection with a Federal Energy Regulatory Commission project.  Records not
   rounded to U.S. Geological Survey standards.

EXTREMES FOR PERIOD OF RECORD.--Maximum contents, 126,503 acre-ft, June 2, 3, 1969; maximum elevation,
   3,335.86 ft, June 3, 1969; 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, 124,695 acre-ft, May 16, elevation, 3,334.26 ft; minimum,
   20,247 acre-ft, Sept. 30, elevation, 3,197.24 ft.

                         Capacity table (elevation, in feet, and contents, in acre-feet)
                 (Based on table provided by Southern California Edison Co., dated Nov. 6, 1959)

          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          3,336    126,661

                    RESERVOIR STORAGE (ACRE-FEET), WATER YEAR OCTOBER 1995 TO SEPTEMBER 1996
                                        DAILY OBSERVATION AT 2400 HOURS

DAY       OCT      NOV      DEC      JAN      FEB      MAR      APR      MAY      JUN      JUL      AUG      SEP

  1     90219    66686    43697    36163    45923    76380    37760    86831   121448   117962    98598    55413
  2     89216    65318    42870    36037    47196    72706    38017    93902   121837   119995    97737    53956
  3     88421    64758    42059    36413    48486    69826    37415    99576   122171   120903    96795    52674
  4     87822    64439    41250    36793    52210    69645    36338   104152   122160   120494    95830    50993
  5     87023    63530    40450    36163    62906    69120    35327   108955   122194   120250    95011    49371

  6     86237    62743    39530    35790    67561    69448    34936   113549   122529   120195    93959    48057
  7     85446    61864    38876    35418    70214    64918    35475   118297   123133   120150    92646    46699
  8     84666    60918    38101    34930    71926    62705    36882   121437   122887   120471    91256    45422
  9     84077    60138    37071    34689    73280    61214    38840   121592   122674   120471    90107    44061
 10     83103    59488    36309    34203    74381    59745    40218   121848   122328   120372    88780    42523

 11     82322    57661    36060    33846    75301    58766    41009   122384   121949   120228    87372    40947
 12     81356    57023    39664    33484    75848    57958    41797   122663   121793   120516    85773    39257
 13     80397    56388    41114    33361    76594    56676    41816   122596   121793   120494    84367    37534
 14     79641    55616    41785    33245    77333    54951    42147   122350   121303   119929    83301    36315
 15     78880    55283    42059    33123    77892    53098    43257   124019   121559   119066    82206    35270

 16     77944    54664    42190    34203    79020    51432    45988   124695   121503   117649    80627    34013
 17     77384    53735    42059    35418    81883    50079    48372   122440   121570   115846    79081    32681
 18     76646    52971    41785    36037    83626    49632    50349   122708   121570   113845    77961    31310
 19     75720    52365    41386    36663    88947    50044    50501   122026   121492   111772    76345    29768
 20     74977    51453    40984    37047    96269    50355    49955   121681   121537   109523    74661    28140

 21     74423    50556    40450    37302    99398    50632    48978   121459   121481   107939    73018    27680
 22     73694    49811    39913    37302    99398    50847    48097   121437   121247   106582    71234    27268
 23     72958    49073    39664    37302    97303    50058    47924   121236   121225   105994    69226    26368
 24     72235    48198    39136    37564    95239    48674    49025   121737   121069   105267    67293    24606
 25     71509    47334    38749    38077    93400    47170    52013   121581   120615   104644    65422    22686

 26     70968    46771    37969    38334    90760    45441    56765   121080   119962   103520    64638    21995
 27     70255    45923    37326    38858    87363    43882    62449   121181   119143   102969    62922    21465
 28     69366    45085    36816    40169    83824    42914    67895   120981   117756   102320    62210    21018
 29     68653    44640    36309    41362    80920    41294    73204   120947   116410   101394    60501    20647
 30     67074    44575    36187    42172      ---    39664    79755   120936   116815   100522    58668    20247
 31     66370      ---    36524    43812      ---    38179      ---   121136      ---    99398    56883      ---

MAX     90219    66686    43697    43812    99398    76380    79755   124695   123133   120903    98598    55413
MIN     66370    44575    36060    33123    45923    38179    34936    86831   116410    99398    56883    20247
 a    3273.01  3242.80  3229.70  3241.61  3290.25  3232.49  3288.93  3331.08  3330.90  3310.12  3260.68  3197.24
 b     -25298   -21795    -8051    +7288   +37108   -42741   +41576   +41381    -4321   -17417   -42515   -36636

CAL YR 1995  b  -6873
WTR YR 1996  b -71421

  a Elevation, in feet, at end of month.
  b Change in contents, in acre-feet.