Station list     Available data
ILLINOIS RIVER BASIN


05573540       SANGAMON RIVER AT ROUTE 48 AT DECATUR, IL



LOCATION.-- Lat 39°49'52", long 88°58'35", in NE1/4NE1/4 sec.21, T.16 N., R.2 E., Macon County, Hydrologic Unit 07130006, on right upstream side of bridge on State Highway 48 in Decatur, 1.2 mi downstream from Lake Decatur Dam, 2.5 mi upstream from Stevens Creek, and at mile 129.0.

DRAINAGE AREA.-- 938 mi2.

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

DISCHARGE: October 1982 to current year.
 

STAGE: Water years 1994-2000.
SURFACE-WATER QUALITY
 

CHEMICAL: Water years 1979-91.

REVISED RECORDS.-- WDR IL-94-2: 1992

GAGE.-- Water-stage recorder, phone telemeter, and crest-stage gage. Datum of gage is 583.43 ft above sea level.

REMARKS.-- Flow regulated by Lake Decatur Dam, 1.2 mi upstream.

EXTREMES FOR PERIOD OF RECORD.--
SURFACE-WATER DISCHARGE AND STAGE: Maximum discharge, 17,100 ft3/s, Apr. 15, 1994, gage height, 21.12 ft; maximum gage height, 23.04 ft, May 2, 1983, discharge, 12,400 ft3/s; no flow in some years.

REMARKS FOR CURRENT YEAR.-- Records fair except those for estimated daily discharges, which are poor.
DISCHARGE, IN CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000
DAILY MEAN VALUES
DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP
 
1 3.4   3.3 5.3 1.3   e1.2 192    5.7   339    913  516  7.2 2.9
2 2.5   3.5 5.4 1.5   1.3 188    1.2   426    788  517  13    2.9
3 5.2   3.5 5.6 7.4   1.4 188    .42 271    616  543  11    3.1
4 4.1   16    6.0 6.7   1.5 188    e.10 73    398  543  5.5 2.8
5 2.9   20    41    4.3   1.3 188    e.10 3.9 476  2360  103    2.7
 
6 2.6   13    24    3.2   1.3 118    15      10    577  1930  193    2.7
7 2.9   9.2 9.0 2.4   1.3 20    163      38    529  1120  146    2.7
8 33      7.8 4.5 1.9   1.3 5.9 248      74    334  1030  73    2.5
9 14      6.9 3.1 1.9   1.4 2.9 146      128    357  585  15    2.4
10 5.2   6.0 3.2 2.0   2.3 1.5 13      246    400  475  6.3 4.9
 
11 1.8   4.9 2.0 1.7   2.4 1.9 2.2   277    366  710  4.4 2.0
12 .92 4.4 1.7 1.4   2.4 1.6 .36 229    256  1100  3.5 5.4
13 1.2   4.2 1.3 1.4   2.4 163    e.10 293    404  786  3.2 1.8
14 1.2   4.1 2.3 1.1   2.4 253    e.10 505    670  380  2.9 3.5
15 1.3   3.6 2.6 1.1   2.4 37    e.10 565    857  325  2.9 1.7
 
16 1.6   3.4 2.6 .99 2.5 181    18      304    638  343  2.9 1.7
17 2.0   3.2 2.3 .78 2.4 195    331      167    480  351  17    1.7
18 1.8   3.2 1.8 .76 67    21    338      203    566  244  18    1.6
19 1.7   3.3 1.7 .96 35    136    144      347    277  61  3.3 1.7
20 1.6   3.1 1.7 1.1   16    405    42      372    130  106  2.7 2.1
 
21 1.6   3.1 1.3 .95 8.6 590    72      215    909  137  2.7 1.8
22 1.8   3.4 1.1 1.0   6.1 554    171      106    1260  40  3.9 2.4
23 1.7   7.5 1.0 1.1   5.4 67    295      211    1490  209  4.4 2.0
24 1.6   11    1.2 1.1   6.5 11    552      256    1530  199  3.2 24   
25 1.5   9.2 1.2 1.1   7.3 64    694      200    1440  36  2.8 15   
 
26 1.5   8.1 1.3 1.1   13    392    652      94    1520  19  4.0 5.1
27 1.5   7.1 1.1 1.0   20    371    277      323    1240  15  2.9 3.0
28 1.8   6.4 1.2 .96 170    310    123      1520    1010  12  2.8 2.4
29 2.0   6.0 1.2 e1.0   248    171    217      1730    683  53  2.9 2.1
30 2.3   5.5 1.3 e1.1   ---    55    226      973    494  42  2.7 2.1
 
31 2.8   ---    1.3 e1.2   ---    57    ---      1180    ---  17  2.8 ---   

TOTAL 111.02 193.9 140.3 55.50 634.1 5128.8 4747.38 11678.9 21608 14804 668.9 112.7
MEAN 3.58 6.46 4.53 1.79 21.9 165 158 377 720 478 21.6 3.76
MAX 33 20 41 7.4 248 590 694 1730 1530 2360 193 24
MIN .92 3.1 1.0 .76 1.2 1.5 .10 3.9 130 12 2.7 1.6

e Estimated
STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1983 - 2000, BY WATER YEAR (WY)
MEAN 234 575 817 682 831 1130 1127 1473 935 399 116 124
MAX 2217 4041 2294 3087 2230 2802 3674 4027 3131 1947 515 1736
(WY) 1994 1986 1991 1993 1984 1998 1994 1995 1998 1993 1985 1993
MIN .24 3.67 2.21 1.79 21.9 165 83.8 129 17.3 2.69 .33 .18
(WY) 1995 1983 1990 2000 2000 2000 1986 1988 1988 1989 1996 1998

SUMMARY STATISTICS FOR 1999 CALENDAR YEAR FOR 2000 WATER YEAR WATER YEARS 1983 - 2000
ANNUAL TOTAL 174855.02 59883.50    
ANNUAL MEAN 479      164          703         
HIGHEST ANNUAL MEAN 1511          1993
LOWEST ANNUAL MEAN 164          2000
HIGHEST DAILY MEAN 4040          Apr 21 2360              Jul 5 16400          Apr 15 1994
LOWEST DAILY MEAN .92     Oct 12 .10         A .00     B
ANNUAL SEVEN-DAY MINIMUM 1.1       Jan 10 .93         Jan 16 .00     Oct 8 1988
INSTANTANEOUS PEAK FLOW 3980              Jul 5 17100      C Apr 15 1994
INSTANTANEOUS PEAK STAGE 14.10         Jul 5 23.04 D May 2 1983
INSTANTANEOUS LOW FLOW  E
10 PERCENT EXCEEDS 1310      543          2050         
50 PERCENT EXCEEDS 40      5.9       222         
90 PERCENT EXCEEDS 1.7   1.2       1.5      
A - Estimated, Apr. 4-5 and 13-15.
B - Many days in some years.
 C - Gage height, 21.12 ft.
 D - Discharge, 12,400 ft3/s.
 E - Minimum unknown, probably occurred during periods when Lake Decatur Dam was closed Apr. 4-6 and 12-16.


Table of Contents

Introduction

Station Descriptions

Surface-Water Data

Ground-Water Data

Meteorological Data

Biological Data