10263000 MOJAVE RIVER AT AFTON, CA

LOCATION.-Lat 35°02'14", long 116°23'00", in NW 1/4 SE 1/4 sec.18, T.11 N., R.6 E., San Bernardino County, Hydrologic Unit 18090208, on right bank side of right pier of Union Pacific Railroad bridge, 0.3 mi west of Afton, and 63 mi east of Barstow. 
DRAINAGE AREA.-2,121 mi2. 
PERIOD OF RECORD.-October 1929 to September 1932, October 1952 to current year. Records for water year 1930 incomplete; yearly estimate published in WSP 1314. Records for water years 1979 and 1980 incomplete; discharge measurements only were published at that time. 
REVISED RECORDS.-WSP 1564: 1931. 
GAGE.-Water-stage recorder. Datum of gage is 1,398.15 ft above sea level. Dec. 21, 1929, to Sept. 30, 1932, at site 1.7 mi downstream at different datum; October 1952 to May 1978, at datum 2 ft higher. 
REMARKS.-Records poor. Natural flow affected by ground-water withdrawals, diversions, municipal use, and storage in reservoirs 100 mi upstream. For description of upstream reservoirs see Mojave River at Barstow (station 10262500). See schematic diagram of Mojave River Basin.
EXTREMES FOR PERIOD OF RECORD.-Maximum discharge, 18,000 ft3/s, Jan. 26, 1969, gage height, 12.40 ft (present datum), from rating curve extended above 3,200 ft3/s on basis of slope-area measurement of peak flow; no flow at times during many years. 
EXTREMES FOR CURRENT YEAR.-Peak discharges greater than base discharge of 100 ft3/s, or maximum: 
  			Discharge	Gage height			Discharge	Gage height
  	Date	Time	(ft3/s)	(ft)	Date	Time	(ft3/s)	(ft)
  	Feb. 25	1245	743	4.24	Sept. 4	1515	642	4.12	

        DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998                   

                       DAILY MEAN VALUES                                                
 
DAY       OCT      NOV      DEC      JAN      FEB      MAR      APR      MAY      JUN      JUL      AUG      SEP
 
  1       .44      .67      .74      .87     1.0      1.2       .89      .30      .17      .03      .00      .06
  2       .39      .68      .73      .87     1.0      1.1       .69      .32      .15      .03      .00      .06
  3       .36      .66      .67      .84     1.6      1.1       .68      .33      .14      .02      .00      .07
  4       .38      .63      .65      .84     2.0       .98      .65      .33      .17      .01      .00   149   
  5       .35      .62      .74      .81      .96      .96      .66      .38      .20      .01      .00    10   
 
  6       .34      .63      .88      .80     1.0       .88      .66      .47      .17      .00      .00      .38
  7       .31      .64      .89      .80     1.1       .77      .61      .41      .15      .00      .00      .28
  8       .34      .63      .80      .84     1.3       .85      .59      .39      .18      .00      .00      .24
  9       .33      .63      .72      .85      .87      .87      .60      .34      .18      .00      .00      .21
 10       .34      .64      .70     1.0       .74      .88      .61      .34      .18      .00      .00      .19
 
 11       .36      .63      .70      .95      .76      .89      .57      .35      .19      .00     4.7       .18
 12       .39      .64      .70      .95      .74      .81      .55      .36      .17      .00      .20      .17
 13       .36      .74      .70      .92      .76      .85      .50      .49      .19      .00      .04      .20
 14       .39      .72      .64      .87      .95     1.2       .53      .52      .21      .00      .02      .20
 15       .42      .64      .66      .91     1.0      1.0       .55      .44      .18      .00      .03      .19
 
 16       .44      .64      .72      .88      .74      .90      .52      .39      .14      .00      .61      .16
 17       .44      .64      .76      .87     1.5       .89      .50      .33      .12      .00      .07      .13
 18       .44      .64      .77      .81      .86      .82      .51      .30      .16      .00      .04      .11
 19       .48      .64      .76      .80      .71      .85      .50      .27      .14      .00      .04      .13
 20       .51      .62      .74      .78      .98      .88      .47      .26      .11      .00      .05      .13
 
 21       .53      .62      .81      .79      .64      .89      .44      .25      .09     1.7       .05      .14
 22       .52      .64      .81      .80      .71      .79      .43      .25      .08      .13      .04      .17
 23       .53      .63      .72      .84      .63      .75      .39      .25      .09      .08      .03      .18
 24       .57      .64      .67      .84   118         .73      .34      .25      .09      .06      .02      .19
 25       .59      .64      .67      .85   162         .85      .43      .25      .09      .03      .02      .20
 
 26       .58      .67      .65      .89    30        1.0       .40      .23      .08      .01      .01      .17
 27       .63      .71      .67      .94     2.0       .88      .36      .25      .08      .00      .00      .18
 28       .66      .70      .70      .93     1.3       .91      .36      .26      .07      .00      .00      .20
 29       .68      .74      .72      .96      ---      .80      .35      .24      .05      .00      .00      .19
 30       .63      .74      .74      .96      ---      .73      .33      .22      .03      .00      .00      .20
 31       .63      ---      .82      .96      ---      .75      ---      .20      ---      .00      .02      ---
 
TOTAL   14.36    19.71    22.65    27.02   335.85    27.76    15.67     9.97     4.05     2.11     5.99   163.91
MEAN      .46      .66      .73      .87     12.0      .90      .52      .32      .14     .068      .19     5.46
MAX       .68      .74      .89      1.0      162      1.2      .89      .52      .21      1.7      4.7      149
MIN       .31      .62      .64      .78      .63      .73      .33      .20      .03      .00      .00      .06
AC-FT      28       39       45       54      666       55       31       20      8.0      4.2       12      325
 


STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1930 - 1998, BY WATER YEAR (WY)                                 
 DAY       OCT      NOV      DEC      JAN      FEB      MAR      APR      MAY      JUN      JUL      AUG      SEP
MEAN      .77      .96     2.80     13.9     45.2     18.2     2.92      .68      .41      .62     1.38      .90
MAX      2.97     2.29     63.9      347      876      415     56.4     1.80     1.58     3.81     18.0     5.46
(WY)     1993     1981     1966     1969     1993     1978     1969     1931     1981     1997     1984     1998
MIN      .000     .000      .21      .34      .59      .22      .20     .099     .000     .000     .000     .000
(WY)     1967     1969     1978     1976     1975     1975     1977     1977     1976     1966     1966     1966
 
SUMMARY STATISTICS           FOR 1997 CALENDAR YEAR        FOR 1998 WATER YEAR           WATER YEARS 1930 - 1998
 
ANNUAL TOTAL                         312.42                     649.05                                          
ANNUAL MEAN                             .86                       1.78                       7.17               
HIGHEST ANNUAL MEAN                                                                        100              1969
LOWEST ANNUAL MEAN                                                                            .22           1975
  HIGHEST DAILY MEAN                   105     Jul 23             162     Feb 25           10000       Feb 20 1993
  LOWEST DAILY MEAN                       .00  Jun 28                .00  Jul  6                .00    Jun 28 1961
  ANNUAL SEVEN-DAY MINIMUM                .00  Jul  6                .00  Jul  6                .00    Jul 14 1961
  INSTANTANEOUS PEAK FLOW                                         743     Feb 25           18000       Jan 26 1969
  INSTANTANEOUS PEAK STAGE                                          4.24  Feb 25              12.40    Jan 26 1969
ANNUAL RUNOFF (AC-FT)                620                       1290                       5190                  
10 PERCENT EXCEEDS                     1.1                         .93                       1.6                
50 PERCENT EXCEEDS                      .62                        .52                        .79               
90 PERCENT EXCEEDS                      .00                        .01                        .05