USGS CD-ROM: Current Year Discharge

05525000 IROQUOIS RIVER AT IROQUOIS, IL

LOCATION.--Lat 40°49'25", long 87°34'55", in NE¼ SE¼ sec.15, T.27 N., R.11 W., Iroquois County, Hydrologic Unit 07120002, on left bank at upstream side of bridge on U.S. Highway 52 in Iroquois, 500 ft upstream from a railroad bridge, 4.5 mi downstream from Indiana-Illinois State line, and at mile 50.4.

DRAINAGE AREA.--686 mi².

PERIOD OF RECORD.--October 1944 to current year.

GAGE.--Water-stage recorder and crest-stage gage. Datum of gage is 614.34 ft above sea level. Prior to Aug. 5, 1945, nonrecording gage at same site and datum.

REMARKS.--Records good except those for Dec. 2 - Mar. 27, which are fair, and those for estimated daily discharges, which are poor. Recording raingage and gage-height telemeter at station.

DISCHARGE, IN 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	75	140	431	284	728	462	2420	1260	360	2290	222	67
2	75	129	400	263	734	430	2300	1350	341	2380	196	62
3	75	129	337	286	709	409	2120	1350	317	2200	175	61
4	75	135	287	476	669	395	1950	1870	299	2460	167	60
5	75	136	257	1030	627	377	1760	2150	288	2710	387	61

6	75	134	235	1530	564	360	1550	2180	278	2300	847	60
7	73	127	215	e2000	512	352	1350	2500	265	2690	1130	63
8	70	122	198	2400	465	393	1330	4530	254	4040	1260	63
9	68	120	187	3100	432	1280	1400	5050	308	3740	1240	70
10	68	120	184	3370	408	2240	1800	4830	468	3140	1100	68

11	69	116	187	3330	408	2750	1900	4450	760	2460	879	61
12	73	112	195	3070	554	3080	1820	3960	1570	1800	611	57
13	74	108	195	2680	735	3110	1670	3390	1930	1210	405	54
14	73	108	196	2270	790	2920	1570	2770	2060	809	298	50
15	74	108	191	1880	758	2630	1510	2220	2050	577	247	48

16	78	111	188	1510	690	2340	1610	1750	1950	460	212	47
17	79	117	190	1170	648	2370	1660	1350	2120	394	182	49
18	77	118	206	908	752	3950	1570	1030	2160	348	162	55
19	75	112	224	711	872	4860	1450	816	2220	314	146	59
20	72	111	226	590	906	5120	1270	701	2200	290	132	56

21	70	117	225	517	881	5580	1190	661	2000	271	119	54
22	69	123	221	474	809	5680	1240	613	1750	353	108	52
23	68	128	223	e445	736	5340	1300	567	1440	802	100	51
24	67	130	261	e415	672	4830	1310	559	1130	1000	95	50
25	66	131	368	e400	613	4260	1230	555	869	1040	91	48

26	69	128	496	e385	566	3700	1140	520	663	909	85	47
27	80	125	524	363	540	3100	1060	477	525	656	83	47
28	114	138	488	374	506	2860	983	439	439	458	80	48
29	171	190	428	465	---	3030	932	414	512	353	78	46
30	174	366	378	607	---	2820	1070	399	1700	293	75	45

31	156	---	333	695	---	2580	---	380	---	251	73	---

TOTAL	2577	3989	8674	37998	18284	83608	45465	55091	33226	42998	10985	1659
MEAN	83.1	133	280	1226	653	2697	1516	1777	1108	1387	354	55.3
MAX	174	366	524	3370	906	5680	2420	5050	2220	4040	1260	70
MIN	66	108	184	263	408	352	932	380	254	251	73	45
CFSM	.12	.19	.41	1.79	.95	3.93	2.21	2.59	1.61	2.02	.52	.08
IN.	.14	.22	.47	2.06	.99	4.53	2.47	2.99	1.80	2.33	.60	.09

e Estimated

STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1945 - 1998, BY WATER YEAR (WY)
MEAN	253	352	553	640	807	1097	1104	859	742	424	143	191
MAX	2556	1878	1794	3030	2213	3462	3116	1944	3496	1958	595	2020
(WY)	1994	1986	1968	1950	1950	1982	1950	1981	1958	1951	1990	1993
MIN	10.6	18.0	16.9	20.6	27.7	94.8	249	141	53.7	23.4	11.4	11.7
(WY)	1957	1957	1964	1945	1963	1957	1946	1958	1988	1988	1988	1964

SUMMARY STATISTICS	FOR 1997 CALENDAR YEAR		FOR 1998 WATER YEAR		WATER YEARS 1945 - 1998
ANNUAL TOTAL	289460		344554
ANNUAL MEAN	793		944		595
HIGHEST ANNUAL MEAN					1323	1993
LOWEST ANNUAL MEAN					121	1964
HIGHEST DAILY MEAN	5990	Feb 28	5680	Mar 22	10200	Jun 14 1958
LOWEST DAILY MEAN	66	Oct 25	45	Sep 30	5.5	Sep 13 1964
ANNUAL SEVEN-DAY MINIMUM	69	Oct 20	47	Sep 24	6.6	Sep 8 1964
INSTANTANEOUS PEAK FLOW			5740 A	Mar 22	10400	Jun 13 1958
INSTANTANEOUS PEAK STAGE			21.96 B	May 9	26.31	Jun 13 1958
INSTANTANEOUS LOW FLOW			45	Sep 29-30	5.2	Sep 13 1964
ANNUAL RUNOFF (CFSM)	1.16		1.38		.87
ANNUAL RUNOFF (INCHES)	15.70		18.68		11.79
10 PERCENT EXCEEDS	1950		2530		1630
50 PERCENT EXCEEDS	366		439		270
90 PERCENT EXCEEDS	85		69		32

A - Gage height, 21.60 ft.
B - Discharge, 5,110 ft³/s.