Station list     Available data
ILLINOIS RIVER BASIN


05586100       ILLINOIS RIVER AT VALLEY CITY, IL



LOCATION.-- Lat 39°42'12", long 90°38'43", in SE1/4NW1/4 sec.34, T.15 N., R.14 W., Scott County, Hydrologic Unit 07130011, on upstream side of Norfolk & Southern Corporation Railroad bridge at Flints Creek, 0.4 mi east of Valley City, 1.8 mi downstream from Mauvaise Terre Creek, and at mile 61.3.

DRAINAGE AREA.-- 26,743 mi2, does not include diversion from Lake Michigan through the Chicago Sanitary and Ship Canal, which has occurred since Jan. 17, 1900.

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

DISCHARGE: October 1938 to current year. Prior to October 1960, at site 0.2 mi upstream at same datum. Prior to October 1989, published as "at Meredosia." Records are considered equivalent.
 

STAGE: Water years 1995-2001.
SURFACE-WATER QUALITY
 

CHEMICAL: Water years 1975-93 and 1996 to current.
 

SEDIMENT: Water years 1980 to current.
 

SPECIFIC CONDUCTANCE: Water years 1975-81.
 

WATER TEMPERATURE: Water years 1975-81.
 

MISCELLANEOUS: Contaminants in streambed sediments, October 1996; contaminants in fish tissue, October 1996.
BIOLOGICAL
 

ALGAE: Water years 1980-81.
 

BENTHIC MACROINVERTEBRATES: Water years 1997-98.
 

FISH: Water year 1998.
 

HABITAT: Water years 1997 and 1998.

GAGE.-- U.S. Army Corps of Engineer's water-stage recorder, satellite telemeter and rain gage, crest-stage gage, and water-quality monitor. Datum of gage is 418.00 ft above sea level (levels by U.S. Army Corps of Engineers).

REMARKS.-- Occasional regulation at low flow by navigation dam at La Grange. Since Jan. 17, 1900, flow has included diversion from Lake Michigan through Chicago Sanitary and Ship Canal. Suspended-sediment samples were collected by a local observer twice weekly with additional samples collected during high runoff periods. Since February 1994, samples used to compute sediment record have been collected at upstream side Rt. 106 bridge at Florence at mile 56.

EXTREMES FOR PERIOD OF RECORD.--
SURFACE-WATER DISCHARGE AND STAGE: Maximum discharge, 123,000 ft3/s, May 26-28, 1943; maximum gage height, 28.61 ft, May 26, 1943; minimum daily discharge, 1,330 ft3/s, Sept. 2, 1984.
SUSPENDED-SEDIMENT CONCENTRATIONS: Maximum daily, 3,720 mg/L, Apr. 14, 1981; minimum daily, 14 mg/L, Dec. 26, 1984, July 21, 1993.
SUSPENDED-SEDIMENT LOADS: Maximum daily, 410,000 tons, June 4, 1980; minimum daily, 172 tons, Sept. 2, 1984.

EXTREMES FOR CURRENT YEAR.--
SUSPENDED-SEDIMENT CONCENTRATIONS: Maximum daily, 1,300 mg/L, June 6; minimum daily, 36 mg/L, May 16.
SUSPENDED-SEDIMENT LOADS: Maximum daily, 140,000 tons, June 6; minimum daily, 925 tons, Nov. 1.
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 11300  8910  13600  e7100  32400  70200  36900  25500  27500  21300  11200  10700 
2 10100  8200  13300  e7100  37500  72500  35500  23400  28600  19800  9860  10600 
3 9090  7450  13500  e7100  39800  73000  34200  20600  29300  17200  9920  10600 
4 11200  8280  12900  e7100  41000  73300  32600  18900  e31000  15800  10800  9530 
5 13700  9120  11000  e7000  41000  72500  31200  18600  e34000  15000  12200  9860 
 
6 14000  10700  11000  e7000  41100  71100  29600  e18200  e40000  16200  12900  10200 
7 14500  9650  10700  e7000  40500  69300  27700  e18000  e46000  16300  12100  8430 
8 14600  9230  9790  e6900  39800  66800  24900  e17600  e49000  15500  10200  7010 
9 14400  11200  10200  e6900  42600  63800  21900  e17200  e51000  14900  9370  7400 
10 14100  14600  10200  e6800  45200  61100  23800  e17200  e52000  14800  8220  8860 
 
11 13100  17500  10600  e6900  47100  58600  28100  e17600  e53000  14700  8320  9820 
12 13500  18900  9880  e7100  50200  56400  32000  e17800  e54000  14300  8290  10200 
13 12700  19900  e9500  e7300  53500  54000  34000  e18000  e54000  13900  8330  9810 
14 11300  20100  e8500  e7600  57500  51900  35500  e18300  54100  12900  7870  9700 
15 11300  20500  e7000  e8200  60600  50400  36300  e19000  53500  11900  6920  9720 
 
16 12000  20500  e6200  e9000  62600  49900  36000  e19800  52600  10200  6720  9020 
17 11700  20100  e7200  e10000  62900  50200  35600  e21000  51800  8600  6230  7560 
18 11200  20300  e7500  e11400  63200  49600  35200  e22600  49900  8880  6360  6910 
19 9810  20000  e7400  e12500  62900  48600  34400  e24500  47600  8910  5950  8080 
20 9440  18500  e7000  e14000  61900  48300  33700  e26500  45400  9530  6160  8270 
 
21 8900  17800  e6400  e15200  60800  48200  32800  e28000  43900  8860  7460  12500 
22 8930  16500  e7200  e17600  59500  47900  31900  e27500  42300  8620  7090  13800 
23 9560  14700  e8000  e17000  57900  47500  32000  e26500  40700  8480  14700  14200 
24 9700  12400  e8800  16500  57000  46800  31200  e25500  38600  8360  19200  14600 
25 9310  12300  e9600  13200  59400  45700  30500  e24000  36500  9210  18000  15700 
 
26 8720  12800  e9500  12600  61200  44500  29400  21700  34400  11400  17000  15800 
27 9020  12200  e9200  10300  63200  43200  28900  21200  32400  13400  16900  15300 
28 9440  12100  e8300  10500  66600  42000  28100  21300  30400  14100  15600  14100 
29 10500  11900  e7700  16900  ---  40700  27200  21700  28900  13000  13900  12800 
30 10500  12600  e7400  28700  ---  39500  26700  23500  24900  12000  13900  11600 
 
31 10200  ---  e7200  29000  ---  38400  ---  25800  ---  11800  13000  --- 

TOTAL 347820 428940 286270 351500 1468900 1695900 937800 667000 1257300 399850 334670 322680
MEAN 11220 14300 9235 11340 52460 54710 31260 21520 41910 12900 10800 10760
MAX 14600 20500 13600 29000 66600 73300 36900 28000 54100 21300 19200 15800
MIN 8720 7450 6200 6800 32400 38400 21900 17200 24900 8360 5950 6910
e Estimated
STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1939 - 2001, BY WATER YEAR (WY)
MEAN 12710 14330 17730 19750 24730 33800 37460 36240 30130 21600 13780 11440
MAX 54840 48900 78130 59540 67060 94940 93800 78160 87690 60820 50850 62870
(WY) 1994 1986 1983 1993 1974 1985 1979 1970 1974 1993 1981 1993
MIN 4258 5519 5923 4808 4144 10870 10010 11170 6207 6649 5709 5164
(WY) 1965 1957 1963 1963 1963 1964 1956 1988 1988 1988 1941 1976

SUMMARY STATISTICS FOR 2000 CALENDAR YEAR FOR 2001 WATER YEAR WATER YEARS 1939 - 2001
ANNUAL TOTAL 5324110      8498630         
ANNUAL MEAN 14550      23280          22790         
HIGHEST ANNUAL MEAN 46810          1993
LOWEST ANNUAL MEAN 8977          1940
HIGHEST DAILY MEAN 43000          Jul 1 73300              Mar 4 123000          May 27 1943
LOWEST DAILY MEAN 4400  A     Jan 29 5950              Aug 19 1330          Sep 2 1984
ANNUAL SEVEN-DAY MINIMUM 4570          Jan 28 6540              Aug 15 2290          Oct 8 1964
MAXIMUM PEAK FLOW 74600      B     Mar 4 123000      C D
MAXIMUM PEAK STAGE 18.49 E     Mar 2 28.61 C May 26 1943
INSTANTANEOUS LOW FLOW 5710              Aug 19
10 PERCENT EXCEEDS 26800      51900          47900         
50 PERCENT EXCEEDS 11200      15300          16100         
90 PERCENT EXCEEDS 6220      7580          6520         

A- Estimated due to backwater from ice.
B- Gage height, 18.33 ft.
C- At Meredosia .
D- May 26-28, 1943.
E- Discharge, 72,300 ft3/s.


Table of Contents

Introduction

Station Descriptions

Surface-Water Data

Ground-Water Data

Meteorological Data

Biological Data