11417500 SOUTH YUBA RIVER AT JONES BAR, NEAR GRASS VALLEY, CA

LOCATION.-Lat 39°17'32", long 121°06'13", in NW 1/4 SE 1/4 sec.32, T.17 N., R.8 E., Nevada County, Hydrologic Unit 18020125, on left bank at Jones Bar, 
100 ft upstream from Rush Creek, 0.9 mi downstream from bridge on State Highway 49, and 5 mi northwest of Grass Valley. 
DRAINAGE AREA.-308 mi2. 
PERIOD OF RECORD.-October 1940 to September 1948, April 1959 to current year. Published as South Fork Yuba River at Jones Bar         1940-48, and as South Yuba 
River at Jones Bar 1959-63. Yearly discharge for the 1947 water year published in WSP 1315-A. 
  SEDIMENT DATA: Water years 1966-74. 
  WATER TEMPERATURE: Water years 1965-79 (daily records). 
  REVISED RECORDS.-WSP 1315-A: 1942-43(M), drainage area at former site. WSP 1931: Drainage area. 
GAGE.-Water-stage recorder and crest-stage gage. Elevation of gage is 1,060 ft above sea level, from river-profile map. Oct. 1, 1940, to Sept. 30, 1948, at site 
150 ft upstream at datum 2.00 ft higher. 
REMARKS.-Records good. Flow regulated by Lake Spaulding, Fordyce Lake, and Bowman Lake (stations 11414140, 11414090, and 11415500) and many smaller reservoirs. 
Diversions into and out of basin for several powerplants and for irrigation. See schematic diagram of Yuba River Basin. 
EXTREMES FOR PERIOD OF RECORD.-Maximum discharge, 53,600 ft3/s, Dec. 22, 1964, gage height, 25.0 ft, from floodmarks, from rating curve extended above 
23,000 ft3/s on basis of slope-area measurement of peak flow; minimum daily, 1.0 ft3/s, Sept. 10-13, 1944. 
EXTREMES OUTSIDE PERIOD OF RECORD.-Flood of Dec. 23, 1955, reached a stage of 30.7 ft, from floodmarks, present datum, at site 100 ft upstream. 

                  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        47       43       77       68      499      614      694      958     1330     1190       92       65
  2        45       43       70       97     1680      588      638     1400     2030     1260       90       65
  3        48       42       66      343     5640      615      834     1390     2050     1260       87       64
  4        41       42       63      778     2150      587      808     1190     1780     1080       85       64
  5        40       42       63      307     1420      553      802     1220     1900     1100       83       65
 
  6        40       42       80      196     2360      562      834     1230     1900     1060       82       72
  7        42       45      803      190     2880      501      764     1380     2220      812       81       73
  8        43       46      509      206     2440      481      697     1830     2330      871       79       70
  9        86       44      229      182     1420      454      640     2120     2160      661       78       73
 10        84       44      152      293     1090      425      626     1840     2280      640       78       72
 
 11        71       48      121     1370     1130      416      638     1290     2410      588       78       69
 12        59       50      105     3100     1000      440      650      913     2570      500       76       68
 13        50       49       96     1480     1040      449      788      941     3320      330       76       67
 14        48       57      100      734     2130      468      719      863     3850      267       75       66
 15        46       60      121     2820     1570      484      658      768     4170      255       73       64
 
 16        44       70       99     1970     1100      546      625      749     4160      237       72       64
 17        43       78       98     2790      954      580      633      792     3630      232       72       65
 18        43       73      115     1990      794      595      630      719     3120      226       72       63
 19        42      119      101     1590      929      534      637      692     3360      220       74       63
 20        43      160       89      943      924      551      653      768     3380      215       73       63
 
 21        42       80       85      689     1500      594      755      945     3160      151       84       64
 22        42       63       78      551     1510     1010      792      900     3110      114       73       63
 23        42       69       74      477     1360     1300      926      859     2580      113       71       65
 24        42       86       71      420     1360     3030     1040      860     1790      108       70       66
 25        41       82       69      371     1060     1800      947     1770     1110      106       69       70
 
 26        42      655       67      334      868     1270      846     2130     1390      103       69       70
 27        68      327       66      324      714     1090      827     1550     1620       99       69       87
 28        43      149       65      313      650     1010      836     1470     1790       97       69       87
 29        42      104       67      596      ---      879      883     1520     1750       95       68       74
 30        42       89       68      526      ---      782      920     1130     1610       94       68       71
 31        43      ---       68      418      ---      739      ---     1020      ---       93       66      ---
 
TOTAL    1494     2901     3935    26466    42172    23947    22740    37207    73860    14177     2352     2052
MEAN     48.2     96.7      127      854     1506      772      758     1200     2462      457     75.9     68.4
MAX        86      655      803     3100     5640     3030     1040     2130     4170     1260       92       87
MIN        40       42       63       68      499      416      625      692     1110       93       66       63
AC-FT    2960     5750     7810    52500    83650    47500    45100    73800   146500    28120     4670     4070
 


STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1941 - 1998, BY WATER YEAR (WY)                                 
 
          OCT      NOV      DEC      JAN      FEB      MAR      APR      MAY      JUN      JUL      AUG      SEP
MEAN     81.2      203      489      797      789      774      699      906      691      127     39.1     39.1
MAX      1197     1350     3756     4865     4078     3029     2804     3323     3618      996     84.9      132
(WY)     1963     1984     1965     1997     1986     1986     1982     1963     1967     1983     1983     1965
MIN      11.7     24.2     37.4     45.0     64.0     67.2     51.1     68.3     31.8     11.6     3.05     1.42
(WY)     1945     1960     1960     1991     1977     1977     1977     1992     1977     1947     1947     1947
 
SUMMARY STATISTICS           FOR 1997 CALENDAR YEAR        FOR 1998 WATER YEAR           WATER YEARS 1941 - 1998
 
ANNUAL TOTAL                      280795                     253303                                             
ANNUAL MEAN                          769                        694                        474                  
HIGHEST ANNUAL MEAN                                                                       1135              1995
LOWEST ANNUAL MEAN                                                                          42.6            1977
  HIGHEST DAILY MEAN                 30300     Jan  1            5640     Feb  3           30300       Jan  1 1997
  LOWEST DAILY MEAN                     38     Aug  9              40     Oct  5               1.0     Sep 10 1944
  ANNUAL SEVEN-DAY MINIMUM              39     Aug 12              42     Oct 19               1.0     Sep  9 1944
  INSTANTANEOUS PEAK FLOW                                        8740     Feb  3           53600       Dec 22 1964
  INSTANTANEOUS PEAK STAGE                                         12.93  Feb  3              25.00    Dec 22 1964
ANNUAL RUNOFF (AC-FT)             557000                     502400                     343600                  
10 PERCENT EXCEEDS                  1470                       1830                       1170                  
50 PERCENT EXCEEDS                    96                        416                        124                  
90 PERCENT EXCEEDS                    40                         49                         28