Station list     Available data
ROCK RIVER BASIN


05444000       ELKHORN CREEK NEAR PENROSE, IL



LOCATION.-- Lat 41°54'10", long 89°41'46", in SW1/4SE1/4 sec.9, T.22 N., R.7 E., Whiteside County, Hydrologic Unit 07090005, on left bank 50 ft upstream from bridge on County Road 2200 N, 2 mi northwest of Penrose, 2.2 mi downstream from Buffalo Creek, 5 mi upstream from Sugar Creek, and at mile 17.5.

DRAINAGE AREA.-- 146 mi2.

PERIOD OF RECORD.--
SURFACE-WATER DISCHARGE AND STAGE
 

DISCHARGE: October 1939 to current year.
 

STAGE: Water years 1994-2001.
SURFACE-WATER QUALITY
 

CHEMICAL: Water years 1979-91.

REVISED RECORDS.-- WSP 925: 1940. WSP 955: 1941. WSP 1175: 1941(P), 1948(P). WSP 1308: 1950(M). WDR IL-72-1: Drainage area.

GAGE.-- Water-stage recorder and phone telemeter. Datum of gage is 657.85 ft above sea level (levels by U.S. Army Corps of Engineers). Prior to Apr. 6, 1940, nonrecording gage at same site and datum.

EXTREMES FOR PERIOD OF RECORD.--
SURFACE-WATER DISCHARGE AND STAGE: Maximum discharge, 6,770 ft3/s, May 17, 1974, gage height, 16.53 ft; maximum gage height, 17.75 ft, Jan. 5, 1946; minimum discharge, 1.9 ft3/s, Jan. 3, 1976, result of freezeup.

EXTREMES OUTSIDE PERIOD OF RECORD.--
SURFACE-WATER DISCHARGE AND STAGE: Flood of June 1938 reached a stage of 19.6 ft, from U.S. Army Corps of Engineers high-water mark.

REMARKS FOR CURRENT YEAR.-- Records good except those for estimated daily discharges, which are poor.
DISCHARGE, IN CUBIC FEET PER SECOND, WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001
DAILY MEAN VALUES
DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP
 
1 87  76  65  e57  e116  224  139  116  152  86  67  52 
2 86  76  64  e57  e100  214  133  115  155  82  113  52 
3 85  74  63  e58  e90  281  129  113  143  110  93  52 
4 92  74  64  60  85  314  125  115  134  96  73  51 
5 90  74  60  60  80  230  129  113  198  86  68  50 
 
6 85  79  e61  59  75  196  170  113  232  82  66  55 
7 83  88  e62  58  69  188  174  111  178  82  65  73 
8 82  78  62  e60  75  189  156  107  161  83  63  80 
9 82  79  e62  e62  987  173  156  104  151  81  63  96 
10 82  85  e62  e60  589  175  150  106  145  78  73  107 
 
11 82  79  e61  56  308  223  159  125  137  75  64  73 
12 82  76  e60  60  195  227  206  119  132  74  61  64 
13 82  75  e59  62  159  234  181  109  129  74  60  59 
14 82  73  e59  63  145  206  169  110  122  72  58  56 
15 81  72  e58  64  134  244  163  109  121  70  59  55 
 
16 80  72  e58  62  122  295  154  104  117  69  76  55 
17 81  70  e58  58  117  241  144  100  112  69  70  55 
18 79  69  e58  55  e112  240  138  97  112  170  66  57 
19 79  69  e58  e54  e108  230  137  94  109  107  66  116 
20 79  67  e58  e54  e105  217  137  93  105  78  63  140 
 
21 79  67  e58  e53  103  208  136  180  105  203  59  100 
22 78  e66  e57  e52  101  198  143  185  104  92  59  91 
23 79  66  e57  e52  104  188  150  151  100  79  59  88 
24 79  66  e57  e51  694  177  135  140  97  76  60  126 
25 79  67  e57  e50  2170  166  133  132  95  74  63  102 
 
26 79  68  e57  e50  534  158  133  131  93  73  64  88 
27 78  67  e57  51  392  154  127  138  91  70  60  80 
28 77  66  e56  71  259  150  122  129  89  69  56  75 
29 76  67  e56  67  ---  147  119  123  88  69  55  71 
30 76  66  e56  186  ---  143  117  118  87  68  54  69 
 
31 76  ---  e57  177  ---  141  ---  121  ---  65  53  --- 

TOTAL 2517 2171 1837 2039 8128 6371 4364 3721 3794 2662 2029 2288
MEAN 81.2 72.4 59.3 65.8 290 206 145 120 126 85.9 65.5 76.3
MAX 92 88 65 186 2170 314 206 185 232 203 113 140
MIN 76 66 56 50 69 141 117 93 87 65 53 50
CFSM .56 .50 .41 .45 1.99 1.41 1.00 .82 .87 .59 .45 .52
IN. .64 .55 .47 .52 2.07 1.62 1.11 .95 .97 .68 .52 .58
e Estimated
STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1940 - 2001, BY WATER YEAR (WY)
MEAN 66.3 72.2 74.4 98.0 154 180 128 129 141 94.1 75.4 67.5
MAX 280 314 267 580 556 588 618 607 560 401 422 225
(WY) 1982 1986 1973 1969 1951 1993 1973 1974 1993 1951 1972 1972
MIN 15.6 17.6 15.4 14.6 22.3 33.6 34.7 25.7 25.8 19.2 23.0 14.7
(WY) 1958 1950 1959 1959 1964 1956 1957 1940 1957 1940 1963 1957

SUMMARY STATISTICS FOR 2000 CALENDAR YEAR FOR 2001 WATER YEAR WATER YEARS 1940 - 2001
ANNUAL TOTAL 55904          41921         
ANNUAL MEAN 153          115          106         
HIGHEST ANNUAL MEAN 275          1973
LOWEST ANNUAL MEAN 30.7       1940
HIGHEST DAILY MEAN 3610              Jun 13 2170              Feb 25 5430          Apr 21 1973
LOWEST DAILY MEAN 40      A     Jan 28 50              B 10          Dec 10 1958
ANNUAL SEVEN-DAY MINIMUM 42              Jan 26 51              Jan 21 10          Dec 9 1958
MAXIMUM PEAK FLOW 2820              Feb 25 6770      C May 17 1974
MAXIMUM PEAK STAGE 11.46         Feb 25 17.75 D Jan 5 1946
INSTANTANEOUS LOW FLOW  E 1.9   F Jan 3 1976
ANNUAL RUNOFF (CFSM) 1.05     .79     .73    
ANNUAL RUNOFF (INCHES) 14.24     10.68     9.89    
10 PERCENT EXCEEDS 272          183          179         
50 PERCENT EXCEEDS 88          82          64         
90 PERCENT EXCEEDS 53          57          26         

A - Estimated due to backwater from ice.
B - Jan. 25 and 26, estimated due to backwater from ice; and Sept. 5.
C - Gage height, 16.53 ft.
D - Discharge, 5,980 ft3/s.
E - Minimum not determined, occurred during periods of ice effect Nov. 22,
Dec. 6-7, Dec. 9-Jan. 3, Jan. 8-10, and Jan. 19-26.
F - Result of freezeup.


Table of Contents

Introduction

Station Descriptions

Surface-Water Data

Ground-Water Data

Meteorological Data

Biological Data