10263500 BIG ROCK CREEK NEAR VALYERMO, CA

LOCATION.-Lat 34°25'15", long 117°50'19", in SE 1/4 NE 1/4 sec.20, T.4 N., R.9 W., Los Angeles County, Hydrologic Unit 18090206, on left bank, 0.1 mi upstream from Punchbowl Canyon, and 1.9 mi southeast of Valyermo. 
DRAINAGE AREA.-22.9 mi2. 
PERIOD OF RECORD.-January 1923 to current year. Monthly discharge only for June 1938 to January 1939, published in WSP 1314. Prior to October 1954, published as Rock Creek near Valyermo. 
REVISED RECORDS.-WSP 1314: 1938-39. WSP 1564: 1932, 1937, 1939(M). WSP 1927: Drainage area. 
GAGE.-Water-stage recorder and concrete control. Elevation of gage is 4,050 ft above sea level, from topographic map. Prior to May 4, 1938, at same site at different datums. May 4, 1938, to Jan. 26, 1939, at site 0.2 mi downstream (below Punchbowl Canyon) at different datum. 
REMARKS.-Records good except those for estimated daily discharges, which are poor. No regulation or diversion upstream from station. 
EXTREMES FOR PERIOD OF RECORD.-Maximum discharge, 8,300 ft3/s, Mar. 2, 1938, gage height unknown, on basis of slope-area measurement of peak flow; maximum gage height, 7.70 ft Jan. 25, 1969; minimum daily, 0.70 ft3/s, Nov. 5, 1951. 
EXTREMES FOR CURRENT YEAR.-Peak discharges greater than base discharge of 50 ft3/s, or maximum: 
  			Discharge	Gage height			Discharge	Gage height
  	Date	Time	(ft3/s)	(ft)	Date	Time	(ft3/s)	(ft)
  	Dec. 6	0500	169	2.88	Feb. 23	1930	1,660	5.07
  	Feb. 7	2300	162	2.87	Mar. 25	1300	207	3.07
  	Feb. 14	1830	77	2.54	May 5	1615	320	3.35

                  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       1.4      1.7      2.3      4.8      6.6       57       56       66       87       45       26       16
  2       1.7      1.6      2.4      4.9      6.7       54       54       65       88       44       24       16
  3       1.9      1.7      2.4      5.0     14         52       54       71       88       42       23       15
  4       1.7      1.7      2.6      5.0     11         51       52       78       84       43       24       15
  5       1.6      1.7      3.3      5.1      9.5       50       51      202       84       42       23       15
 
  6       1.6      1.8     74        4.9     46         50       50      188       86       41       23       15
  7       1.8      1.8     29        4.8     68         45       48      134       83       39       24       15
  8       1.7      1.8     17        4.8     93         42       46      113       82       39       24       15
  9       1.7      1.8     11        6.0     53         40       46      105       81       38       22       14
 10       1.7      2.0      8.4      9.0     38         38       48       96       80       36       21       14
 
 11       1.8      2.0      7.2      8.5     31         37       50       95       81       36       26       13
 12       1.8      2.0      6.6      7.4     27         36       49      105       79       36       27       13
 13       1.8      2.1      6.1      6.9     25         38       48      100       75       35       27       13
 14       1.7      2.0      5.6      6.6     45         45       47       95       74       34       24       13
 15       1.7      2.0      5.4      6.4     60         43       45      100       76       32       22       12
 
 16       1.6      2.0      5.2      6.3     47         45       43      105       78       32       22       12
 17       1.6      2.0      5.1      6.5     41         46       42      103       78       30       21       12
 18       1.6      2.1      5.1      6.5     33         48       42       98       73       29       21       12
 19       1.7      2.1      5.1      6.6     30         48       43       92       70       27       20       12
 20       1.7      2.1      5.1      6.4     27         47       48       91       68       28       20       11
 
 21       1.7      2.1      5.0      6.4     24         46       55       87       66       29      e19       11
 22       1.7      2.1      4.8      6.3     48         49       65       85       64       29      e18       11
 23       1.6      2.1      4.8      6.3    730         58       67       86       62       28       18       11
 24       1.7      2.1      4.8      6.0    341         63       61       87       59       28       17       11
 25       1.7      2.1      4.8      5.9    136        115       57       91       56      e27       17       11
 
 26       1.7      2.5      4.8      5.9     90        109       55       94       51      e26       17       11
 27       1.7      2.3      4.8      5.9     71         94       54       89       49      e25       16       11
 28       1.7      2.3      4.8      5.9     61         84       55       88       47      e24       16       11
 29       1.7      2.3      4.8      6.2      ---       71       58       90       47       23       16       11
 30       1.7      2.3      4.8      6.3      ---       63       63       88       46       24       16       11
 31       1.7      ---      4.8      6.5      ---       59      ---       88      ---       26       16      ---
 
TOTAL    52.4     60.2    261.9    190.0   2212.8     1723     1552     3075     2142     1017      650      383
MEAN     1.69     2.01     8.45     6.13     79.0     55.6     51.7     99.2     71.4     32.8     21.0     12.8
MAX       1.9      2.5       74      9.0      730      115       67      202       88       45       27       16
MIN       1.4      1.6      2.3      4.8      6.6       36       42       65       46       23       16       11
AC-FT     104      119      519      377     4390     3420     3080     6100     4250     2020     1290      760
 
    e  Estimated.


STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1923 - 1998, BY WATER YEAR (WY)                                 
  
          OCT      NOV      DEC      JAN      FEB      MAR      APR      MAY      JUN      JUL      AUG      SEP
 
MEAN     5.12     7.41     10.5     18.8     31.7     38.6     31.4     28.5     19.4     11.2     8.02     6.36
MAX      19.0      116     67.0      245      303      432      144      120     91.4     42.2     26.5     19.7
(WY)     1984     1966     1947     1969     1980     1978     1978     1941     1978     1983     1983     1983
MIN      1.05     1.09     1.80     2.10     2.39     2.40     2.67     2.35     1.61     1.15     1.09     1.01
(WY)     1952     1952     1991     1951     1951     1951     1951     1951     1961     1961     1961     1961
 
SUMMARY STATISTICS           FOR 1997 CALENDAR YEAR        FOR 1998 WATER YEAR           WATER YEARS 1923 - 1998
 
ANNUAL TOTAL                        2386.2                    13319.3                                           
ANNUAL MEAN                            6.54                      36.5                       18.1                
HIGHEST ANNUAL MEAN                                                                         90.9            1978
LOWEST ANNUAL MEAN                                                                           1.91           1951
  HIGHEST DAILY MEAN                    74     Dec  6             730     Feb 23            3300       Mar  2 1938
  LOWEST DAILY MEAN                      1.4   Oct  1               1.4   Oct  1                .70    Nov  5 1951
  ANNUAL SEVEN-DAY MINIMUM               1.5   Sep 25               1.7   Oct 14                .87    Nov  3 1951
  INSTANTANEOUS PEAK FLOW                                        1660     Feb 23            8300       Mar  2 1938
  INSTANTANEOUS PEAK STAGE                                          5.07  Feb 23               7.70    Jan 25 1969
ANNUAL RUNOFF (AC-FT)               4730                      26420                      13090                  
10 PERCENT EXCEEDS                    12                         86                         38                  
50 PERCENT EXCEEDS                     3.9                       24                          7.5                
90 PERCENT EXCEEDS                     1.7                        1.8                        2.6