11446500 AMERICAN RIVER AT FAIR OAKS, CA

LOCATION.-Lat 38°38'08", long 121°13'36", in SE 1/4 NE 1/4 sec.17, T.9 N., R.7 E., Sacramento County, Hydrologic Unit 18020111, on right bank 2,100 ft 
downstream from Nimbus Dam, 2.4 mi east of Fair Oaks, 8.1 mi downstream from South Fork, and at mile 22.2. 
DRAINAGE AREA.-1,888 mi2. 
PERIOD OF RECORD.-November 1904 to current year. Monthly discharge only for some periods, published in WSP 1315-A. 
  WATER TEMPERATURE: Water years 1961-65. 
  CHEMICAL DATA: Water years 1960-62. 
REVISED RECORDS.-WSP 1181: 1928(M). WSP 1515: 1907(M), 1910, 1931(M), 1943(M). WSP 1931: Drainage area. 
GAGE.-Water-stage recorder. Datum of gage is 71.53 ft above sea level. See WSP 2131 for history of changes prior to July 15, 1970. 
REMARKS.-Records good. Flow regulated by Folsom Lake beginning Feb. 25, 1955 (station 11446200). Some minor regulation of high flows by temporary pondage during 
period of construction January 1953 to February 1955. Diurnal fluctuations from Folsom Powerplant                re-regulated by Nimbus Reservoir, capacity, 
2,800 acre-ft between normal operating elevations 118.5 and 125.0 ft and by Nimbus Powerplant. Many diversions upstream from station for irrigation, municipal, 
and domestic water supply. Diversions for San Juan Suburban Water District, city of Folsom, city of Roseville, and State of California are made at Folsom Dam. 
Diversion to Folsom South Canal from Nimbus Reservoir started in June 1973. Some inflow from Bear and Yuba River Basins. See schematic diagram of lower 
Sacramento River Basin. 
EXTREMES FOR PERIOD OF RECORD.-Maximum discharge, 180,000 ft3/s, Nov. 21, 1950, gage height, 31.85 ft, site and datum then in use; minimum, 3.6 
ft3/s, Aug. 16, 1924. Maximum discharge since regulation by Folsom Lake in 1955, 134,000 ft3/s, Feb. 19, 1986, gage height, 27.96 ft; 
minimum daily, 160 ft3/s, Apr. 17, 1955. 

                  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      1750     2580     2380     2380     4570     5450     7100   e10100    e8980     7470     4030     4000
  2      1740     2600     2370     2420     5130     4980     7160   e10400    e8430     6590     4030     4000
  3      2190     2520     2380     2400    18700     4400     7170    e9750    e7020     5740     4020     4010
  4      2240     2570     2380     2350    33700     4310     7140    e9930    e6030     5240     4030     4020
  5      2240     2570     2380     2400    28600     4410     7180   e10600    e5370     4950     4020     4030
 
  6      2240     2560     2360     1470    17900     4370     7170   e10700    e5290     4900     4000     4020
  7      2240     2470     2380     2220    17000     4380     7210   e10800    e5720     4410     4000     4000
  8      2210     2400     2400     2170    18400     4390     7250   e10900    e5960     4000     4010     3510
  9      2200     2390     2390     2200    14300     4410     7280   e10700    e5960     3950     4000     2110
 10      2210     2400     2390     2230    11900     4410     7220    e9320    e6000     3970     4010     1940
 
 11      2220     2430     2370     2180    10000     4440     7260    e8920    e6030     3940     4000     3940
 12      2210     2480     2390     5530     9270     4410     7320    e8890    e6020     3940     4010     3950
 13      2220     2480     2370     9800     9290     4370     7350   e10100    e6020     3950     4000     3950
 14      2230     2370     2390     8710    10700     4360     7360   e11000    e6140     3960     4020     3970
 15      2230     2330     2400     7880    15300     4340     7290   e10900    e7700     3960     4020     3980
 
 16      2230     2330     2400     7670    14700     4320     7270   e10100    e9070     3970     4020     3990
 17      2340     2360     2390    10600    13400     4360     7300   e10900    e9980     3970     4030     4000
 18      2470     2370     2390    14800    12300     5150     7270   e10700    e9690     4000     4020     4030
 19      2480     2390     2390    13900    11100     7800     7260   e10200    e8750     3990     4010     4000
 20     e2600     2410     2380    11500     9980     9540     7160    e8890    e8000     3990     4020     3970
 
 21     e2940     2410     2410     9490     9160     9560    e7220    e7540    e8170     3990     4020     3980
 22     e3400     2370     2400     8170     9160     9610    e7220    e6560    e8900     4000     3990     4530
 23     e3360     2400     2400     7280     8850     9470    e7230    e5950     8820     3990     3980     4620
 24     e3600     2410     2410     6090     7830     9100    e7850    e5980     8810     3980     3980     4690
 25     e2800     2430     2380     5260     7240    10500    e8900    e5860     8870     4010     4010     4620
 
 26     e2370     2480     2370     4820     7090    11800    e8540    e6050     8780     4010     4000     4520
 27     e2120     2400     2380     4550     6630    11600    e8360    e6520     8890     4020     4000     4500
 28     e2560     2370     2370     4580     6030    10600    e9280    e8770     8990     4010     3980     4490
 29     e2400     2390     2380     4610      ---     9080    e9630    e8890     8800     4010     3990     4500
 30     e2460     2400     2390     4620      ---     7670    e9770    e8860     8360     4010     3990     4540
 31     e2390      ---     2380     4590      ---     7030      ---    e8580      ---     4020     4000      ---
 
TOTAL   74890    73070    73950   178870   348230   204620   228720   283360   229550   134940   124240   120410
MEAN     2416     2436     2385     5770    12440     6601     7624     9141     7652     4353     4008     4014
MAX      3600     2600     2410    14800    33700    11800     9770    11000     9980     7470     4030     4690
MIN      1740     2330     2360     1470     4570     4310     7100     5860     5290     3940     3980     1940
AC-FT  148500   144900   146700   354800   690700   405900   453700   562000   455300   267700   246400   238800
  
    e  Estimated.


STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1905 - 1954, BY WATER YEAR (WY)
 
          OCT      NOV      DEC      JAN      FEB      MAR      APR      MAY      JUN      JUL      AUG      SEP
MEAN      455     1327     2504     4483     5831     6647     8258     8656     5149     1293      342      269
MAX      1430    16450    17360    24290    15540    24710    15640    18200    17720     6336     1497      813
(WY)     1905     1951     1951     1909     1909     1907     1907     1952     1911     1906     1907     1907
MIN       100     85.0      254      284      650      879     1998     1488      206     26.8     15.8     24.4
(WY)     1930     1930     1906     1918     1920     1924     1924     1924     1924     1924     1924     1924
 
 
SUMMARY STATISTICS                      WATER YEARS 1905 - 1954
 
ANNUAL MEAN                              3752
HIGHEST ANNUAL MEAN                      7896              1907
LOWEST ANNUAL MEAN                        731              1924
  HIGHEST DAILY MEAN                     132000       Nov 21 1950
  LOWEST DAILY MEAN                           4.6     Jul 29 1924
  ANNUAL SEVEN-DAY MINIMUM                    4.8     Jul 29 1924
  INSTANTANEOUS PEAK FLOW                180000       Nov 21 1950
  INSTANTANEOUS PEAK STAGE                   31.85    Nov 21 1950
ANNUAL RUNOFF (AC-FT)                 2718000
10 PERCENT EXCEEDS                       9980
50 PERCENT EXCEEDS                       1420
90 PERCENT EXCEEDS                        216
 
 
 


STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1956 - 1998, BY WATER YEAR (WY)                                 
 
          OCT      NOV      DEC      JAN      FEB      MAR      APR      MAY      JUN      JUL      AUG      SEP
MEAN     1922     2424     3994     5579     5644     5203     4296     4358     3820     3654     2795     2291
MAX      4102    11700    19360    31780    31140    19340    17760    14270     9828    10710     4500     4014
(WY)     1970     1984     1965     1997     1986     1983     1982     1995     1983     1995     1983     1998
MIN       284      272      252      350      408      273      258      520     1135      869      855      602
(WY)     1978     1978     1978     1962     1991     1977     1977     1977     1977     1977     1977     1977
 
SUMMARY STATISTICS           FOR 1997 CALENDAR YEAR        FOR 1998 WATER YEAR           WATER YEARS 1956 - 1998
 
ANNUAL TOTAL                     1946090                    2074850                                             
ANNUAL MEAN                         5332                       5685                       3825                  
HIGHEST ANNUAL MEAN                                                                       8854              1983
LOWEST ANNUAL MEAN                                                                         778              1977
  HIGHEST DAILY MEAN                106000     Jan  2           33700     Feb  4          131000       Feb 19 1986
  LOWEST DAILY MEAN                    629     Sep 18            1470     Jan  6             215       Apr 20 1977
  ANNUAL SEVEN-DAY MINIMUM            1030     Sep 13            2090     Oct  1             237       Jan  7 1978
  INSTANTANEOUS PEAK FLOW                                       33800     Feb  4          134000       Feb 19 1986
  INSTANTANEOUS PEAK STAGE                                         15.74  Feb  4              27.96    Feb 19 1986
ANNUAL RUNOFF (AC-FT)            3860000                    4115000                    2771000                  
10 PERCENT EXCEEDS                  8030                      10000                       7680                  
50 PERCENT EXCEEDS                  2410                       4360                       2520                  
90 PERCENT EXCEEDS                  1930                       2370                        918