11481000 MAD RIVER NEAR ARCATA, CA 

LOCATION.-Lat 40°54'35", 1ong 12403'35", in NW 1/4 NW 1/4 sec.15, T.6 N., R.1 E., Humboldt County, Hydrologic Unit 18010102, on right bank 100 ft upstream 
from bridge on U.S. Highway 299, 1.0 mi downstream from Warren Creek, and 2.8 mi northeast of Arcata. 
DRAINAGE AREA.-485 mi2. 
PERIOD OF RECORD.-October 1910 to September 1913, August 1950 to current year. Monthly discharge only for some periods, published in WSP 1315-B. 
REVISED RECORDS.-WSP 2129: 1965(M). 
GAGE.-Water-stage recorder and crest-stage gage. Datum of gage is 10.79 ft above sea level. December 1910 to September 1913, nonrecording gage at site 0.1 mi 
upstream at different datum. Aug. 15, 1950, to July 23, 1956, water-stage recorder at site 0.6 mi upstream at datum 11.00 ft higher. July 24, 1956, to Aug. 10, 
1992, water-stage recorder at different datums, at present site. 
REMARKS.-Records fair. Flow regulated by Ruth Reservoir (station 11480400), 68 mi upstream, beginning in July 1961. Water is diverted 0.5 mi upstream from 
station for municipal supply and industrial use in Humboldt Bay area. 
EXTREMES FOR PERIOD OF RECORD.-Maximum discharge, 81,000 ft3/s, Dec. 22, 1964, gage height, 30.7 ft, prior datum, from high-water profile and 
flood-routing study; minimum daily, 0.10 ft3/s, Aug. 29, 1977. 

                  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        68     1170     1590      673     5420     2990     2830      953     1100      130       57       41
  2       268      460     1100     2260     6590     2980     2430     1000     1010      128       56       38
  3       207      285      840     3220    11600     3230     2220      934      941      127       54       38
  4       141      207      737     5060     8560     2850     2160      926      879      123       52       37
  5       116      159      622     3290     7090     2580     2140      857      799      120       51       37
 
  6        97      196      546     2610     9190     2360     2290      770      720      114       50       37
  7        92      624     2330    e2470     9800     2140     2540      743      687      109       48       38
  8        95      469     3890    e2310    12400     2030     2170     e735      669      106       47       39
  9       553      294     2820    e2190     8950     1880     2010     e731      641      102       45       39
 10       525      229     1940    e1870     6480     1770     2190     e725      587      100       45       40
 
 11       348      295     1450    e4730     5950     1750     2530     e721      550       98       44       40
 12       235      337     1230    e9900     5420     2080     2360     e719      521       97       42       40
 13       149      291      996   e12300     6080     4520     2770      717      474       95       42       38
 14       120      308     2370   e10100     6880     3580     2690      716      504       92       42       36
 15       106      348     4270   e13400     7790     3070     2400      793      532       90       40       36
 
 16        97     1060     2910   e22800     6060     2830     2150      858      418       87       40       36
 17        90     2580     4100   e24500     5390     2590     1950      897      456       83       40       37
 18        86     1110     3370    14800     4670     2340     1800      809      475      103       38       38
 19        82     1170     2390    14400     8560     2150     1660      801      462      100       38       38
 20        81     1630     2150     9240     9120     2040     1560     1260      398       78       38       39
 
 21        79     1030     2320     6380    13200     1950     1450     1290      352       74       38       38
 22        77      718     1740     5510    12100     7980     1380     1030      342       72       42       37
 23        76      973     1450     5300     8060    17300     1350      910      286       70       42       38
 24        74     1450     1250     5150     6000    13600     1520      947     e219       68       40       39
 25        73     2660     1110     4550     4600     9890     1290     1450      199       67       40       40
 
 26        72     3150      988     8630     3850     6290     1180     1280      177       65       41       40
 27        72     2590      861    11400     3350     4830     1100     1250      160       64       41       39
 28        74     1480      771     7460     3180     4020     1050     1600      145       61       41       39
 29        89     1420      719     8610      ---     3320     1000     2000      134       59       41       41
 30       109     2640      701     7810      ---     2780      957     1430      132       59       40       41
 31      1680      ---      673     5990      ---     3040      ---     1220      ---       59       40      ---
 
TOTAL    6031    31333    54234   238913   206340   126760    57127    31072    14969     2800     1355     1154
MEAN      195     1044     1749     7707     7369     4089     1904     1002      499     90.3     43.7     38.5
MAX      1680     3150     4270    24500    13200    17300     2830     2000     1100      130       57       41
MIN        68      159      546      673     3180     1750      957      716      132       59       38       36
AC-FT   11960    62150   107600   473900   409300   251400   113300    61630    29690     5550     2690     2290
 
   e  Estimated.
 
 


STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1911 - 1960, BY WATER YEAR (WY)
 
          OCT      NOV      DEC      JAN      FEB      MAR      APR      MAY      JUN      JUL      AUG      SEP
MEAN      313     1081     2997     4588     4164     2438     1716     1167      358     97.2     40.3     39.3
MAX      2303     2903     9335     9175     9830     5054     3450     2669     1311      210     68.2      128
(WY)     1951     1954     1956     1953     1958     1957     1958     1953     1953     1953     1953     1912
MIN      22.0     32.0      136      852     1232     1028      489      277      104     36.6     19.2     18.2
(WY)     1953     1960     1960     1960     1955     1955     1951     1954     1959     1959     1959     1951
 
 
SUMMARY STATISTICS                      WATER YEARS 1911 - 1960
 
ANNUAL MEAN                              1573
HIGHEST ANNUAL MEAN                      2377              1958
LOWEST ANNUAL MEAN                        943              1955
  HIGHEST DAILY MEAN                      63100       Dec 22 1955
  LOWEST DAILY MEAN                          17       Sep  8 1951
  ANNUAL SEVEN-DAY MINIMUM                   17       Sep  4 1959
  INSTANTANEOUS PEAK FLOW                 77800       Dec 22 1955
  INSTANTANEOUS PEAK STAGE                   27.30    Dec 22 1955
ANNUAL RUNOFF (AC-FT)                 1139000
10 PERCENT EXCEEDS                       4010
50 PERCENT EXCEEDS                        400
90 PERCENT EXCEEDS                         31
 
 


STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1963 - 1998, BY WATER YEAR (WY)                                 
 
          OCT      NOV      DEC      JAN      FEB      MAR      APR      MAY      JUN      JUL      AUG      SEP
MEAN      210     1280     2786     3646     2984     2887     1767      675      237     58.7     44.9     64.9
MAX      2255     6671    10400     8847     9796     7150     6253     1654     1721      152      123      392
(WY)     1963     1974     1965     1970     1986     1975     1963     1995     1993     1964     1983     1986
MIN      21.3     52.6     29.8      135      138      194      165      122     31.2     8.40     7.04     15.0
(WY)     1993     1994     1977     1977     1977     1988     1988     1968     1974     1977     1977     1992
 
SUMMARY STATISTICS           FOR 1997 CALENDAR YEAR        FOR 1998 WATER YEAR           WATER YEARS 1963 - 1998
 
ANNUAL TOTAL                      466454                     772088                                             
ANNUAL MEAN                         1278                       2115                       1381                  
HIGHEST ANNUAL MEAN                                                                       2478              1974
LOWEST ANNUAL MEAN                                                                         151              1977
  HIGHEST DAILY MEAN                 44700     Jan  1           24500     Jan 17           58000       Dec 22 1964
  LOWEST DAILY MEAN                     47     Sep  7              36     Sep 14                .10    Aug 29 1977
  ANNUAL SEVEN-DAY MINIMUM              49     Sep  2              37     Sep 13                .63    Aug 23 1977
  INSTANTANEOUS PEAK FLOW                                       27100     Jan 16           81000       Dec 22 1964
  INSTANTANEOUS PEAK STAGE                                         18.08  Jan 16              30.70    Dec 22 1964
ANNUAL RUNOFF (AC-FT)             925200                    1531000                    1000000                  
10 PERCENT EXCEEDS                  2780                       6160                       3800                  
50 PERCENT EXCEEDS                   480                        809                        277                  
90 PERCENT EXCEEDS                    57                         40                         31