LOCATION.-- Lat 39°49'52", long 88°58'35" (NAD of 1927), 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. |
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DRAINAGE AREA.-- 938 mi2. |
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PERIOD OF RECORD.-- |
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SURFACE-WATER DISCHARGE AND STAGE |
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DISCHARGE: October 1982 to current year. |
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STAGE: Water years 1994-2002. |
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SURFACE-WATER QUALITY |
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CHEMICAL: Water years 1979-91. |
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REVISED RECORDS.-- WDR IL-94-2: 1992 |
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GAGE.-- Water-stage recorder, phone telemeter, and crest-stage gage. Datum of gage is 583.43 ft above NGVD of 1929. |
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REMARKS.-- Flow regulated by Lake Decatur Dam, 1.2 mi upstream. |
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EXTREMES FOR PERIOD OF RECORD.-- |
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SURFACE-WATER DISCHARGE AND STAGE: Maximum discharge, 31,800 ft3/s, May 12, 2002, gage height, 24.33 ft; no flow in some years. |
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REMARKS FOR CURRENT YEAR.-- Records fair except those for Oct. 19 to Nov. 28, July 3 to Sept. 5, and estimated daily discharges, which are poor. |
DISCHARGE, in CFS, WATER YEAR OCTOBER 2001 TO SEPTEMBER 2002 DAILY MEAN VALUES |
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DAY | OCT | NOV | DEC | JAN | FEB | MAR | APR | MAY | JUN | JUL | AUG | SEP |
1 | 1.4 | 901 | 328 | 191 | 3010 | 818 | 1670 | 2990 | 1110 | 276 | e0.10 | 130 |
2 | 1.1 | 73 | 595 | 308 | 3150 | 1290 | 1410 | 2690 | 923 | 150 | e0.10 | 88 |
3 | 2.0 | 17 | 707 | 360 | 2870 | 1370 | 1450 | 2590 | 583 | 198 | 0.19 | 17 |
4 | 1.8 | 15 | 647 | 243 | 2820 | 1580 | 1150 | 2440 | 319 | 202 | 0.18 | 4.5 |
5 | 14 | 17 | 623 | 186 | 2930 | 1840 | 786 | 1770 | e500 | 253 | e0.10 | 2.2 |
6 | 8.3 | 15 | 626 | 185 | 2790 | 1660 | 556 | 927 | 848 | e240 | e0.10 | 1.7 |
7 | 7.4 | 16 | 341 | 258 | 1770 | 1690 | 561 | 4670 | 809 | e180 | e0.10 | 0.99 |
8 | 6.4 | 12 | 152 | 285 | 1190 | 1390 | 1050 | 3180 | 788 | e60 | e0.10 | 1.2 |
9 | 6.8 | 14 | 142 | 187 | 1360 | 1480 | 1320 | 4030 | 759 | e7.0 | e0.10 | 1.0 |
10 | 22 | 10 | 193 | 152 | 1090 | 2320 | 1140 | 3420 | 550 | 9.2 | e0.10 | 0.25 |
11 | 44 | 9.8 | 305 | 201 | 487 | 1960 | 1120 | 3350 | 861 | 4.5 | 0.46 | e0.10 |
12 | 94 | 10 | 374 | 228 | 92 | 1510 | 1050 | 19600 | 2720 | 0.99 | 0.90 | e0.10 |
13 | 38 | 9.2 | 397 | 228 | 949 | 1560 | 966 | 11700 | 2850 | 0.37 | 1.6 | e0.10 |
14 | 34 | 10 | 423 | 205 | 978 | 1330 | 923 | 7010 | 2900 | 0.10 | 1.7 | e0.10 |
15 | 18 | 139 | 433 | 180 | 504 | 1420 | 778 | 5940 | 2730 | 0.22 | 1.5 | 0.17 |
16 | 55 | 214 | 503 | 142 | 259 | 1480 | 518 | 6020 | 2560 | 8.3 | 5.0 | e0.10 |
17 | 23 | 15 | 1250 | 104 | 781 | 929 | 608 | 5580 | 2170 | 1.6 | 0.94 | 3.8 |
18 | 141 | 7.5 | 1990 | 102 | 718 | 547 | 735 | 3720 | 1830 | 0.76 | 3.6 | 1.7 |
19 | 403 | 6.6 | 2150 | 101 | 528 | 604 | 510 | 3660 | 1740 | 0.47 | 8.5 | 5.9 |
20 | 780 | 55 | 1840 | 102 | 2310 | 940 | 564 | 3080 | 1250 | 0.21 | 0.96 | 0.27 |
21 | 229 | 175 | 1540 | 100 | 3230 | 1110 | 1980 | 2360 | 711 | e0.10 | 0.92 | e0.10 |
22 | 18 | 158 | 1280 | 99 | 3140 | 851 | 2690 | 2160 | 710 | 2.0 | 2.4 | e0.10 |
23 | 13 | 159 | 934 | 100 | 3180 | 282 | 1660 | 1840 | 650 | 0.58 | 12 | e0.10 |
24 | 617 | 171 | 498 | 136 | 3100 | 336 | 1540 | 1400 | 304 | 0.35 | 285 | e0.10 |
25 | 1990 | 161 | 769 | 155 | 2800 | 760 | 2790 | 1090 | 385 | 0.29 | 1430 | e0.10 |
26 | 1310 | 157 | 733 | 137 | 2260 | 1230 | 1890 | 1120 | 557 | 0.54 | 1500 | e0.10 |
27 | 1040 | 156 | 577 | 136 | 1720 | 1050 | 2150 | 1050 | 477 | 8.4 | 1610 | e0.10 |
28 | 505 | 162 | 416 | 120 | 1140 | 774 | 4450 | 849 | 529 | 0.34 | 1240 | e0.10 |
29 | 55 | 176 | 357 | 85 | --- | 1420 | 3260 | 885 | 486 | 0.19 | 741 | e0.10 |
30 | 930 | 304 | 281 | 128 | --- | 2020 | 3030 | 1120 | 455 | 0.10 | 267 | e0.10 |
31 | 1740 | --- | 268 | 1470 | --- | 1890 | --- | 883 | --- | 0.11 | 125 | --- |
TOTAL | 10148.2 | 3345.1 | 21672 | 6614 | 51156 | 39441 | 44305 | 113124 | 34064 | 1605.72 | 7239.65 | 260.18 |
MEAN | 327.4 | 111.5 | 699.1 | 213.4 | 1827 | 1272 | 1477 | 3649 | 1135 | 51.80 | 233.5 | 8.673 |
MAX | 1990 | 901 | 2150 | 1470 | 3230 | 2320 | 4450 | 19600 | 2900 | 276 | 1610 | 130 |
MIN | 1.1 | 6.6 | 142 | 85 | 92 | 282 | 510 | 849 | 304 | 0.10 | 0.10 | 0.10 |
e Estimated |
STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1983 - 2002, BY WATER YEAR (WY) | ||||||||||||
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MEAN | 231.6 | 544.7 | 780.2 | 639.3 | 977.7 | 1140 | 1114 | 1514 | 936.1 | 362.2 | 116.8 | 112.5 |
MAX | 2217 | 4041 | 2294 | 3087 | 2803 | 2802 | 3674 | 4027 | 3131 | 1947 | 515 | 1736 |
(WY) | 1994 | 1986 | 1991 | 1993 | 2001 | 1998 | 1994 | 1995 | 1998 | 1993 | 1985 | 1993 |
MIN | 0.24 | 3.67 | 2.21 | 1.79 | 21.9 | 165 | 83.8 | 108 | 17.3 | 2.69 | 0.33 | 0.18 |
(WY) | 1995 | 1983 | 1990 | 2000 | 2000 | 2000 | 1986 | 2001 | 1988 | 1989 | 1996 | 1998 |
SUMMARY STATISTICS | FOR 2001 CALENDAR YEAR | FOR 2002 WATER YEAR | WATER YEARS 1983 - 2002 | |||
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ANNUAL TOTAL | 201722.94 | 332974.85 | ||||
ANNUAL MEAN | 552.7 | 912.3 | 704.0 | |||
HIGHEST ANNUAL MEAN | 1511 | 1993 | ||||
LOWEST ANNUAL MEAN | 164 | 2000 | ||||
HIGHEST DAILY MEAN | 7840 | Feb 26 | 19600 | May 12 | 19600 | May 12 2002 |
LOWEST DAILY MEAN | 0.41 | May 8 | 0.10 | A | 0.00 | B |
ANNUAL SEVEN-DAY MINIMUM | 1.2 | May 2 | 0.10 A | Sep 21 | 0.00 | Oct 8 1988 |
MAXIMUM PEAK FLOW | 31800 C | May 12 | 31800 C | May 12 2002 | ||
MAXIMUM PEAK STAGE | 24.33 | May 12 | 24.33 | May 12 2002 | ||
INSTANTANEOUS LOW FLOW | D | |||||
10 PERCENT EXCEEDS | 1620 | 2630 | 2050 | |||
50 PERCENT EXCEEDS | 158 | 360 | 221 | |||
90 PERCENT EXCEEDS | 3.3 | 0.32 | 1.5 |
D - Minimum unknown, may have occured many days during July-Sept. |
Table of Contents |
Introduction |
Station Descriptions |
Surface-Water Data |
Ground-Water Data |
Meteorological Data |
Biological Data |