05443500 DATA: Discharge Tables, 2003

Station list Available data
ROCK RIVER BASIN

05443500 ROCK RIVER AT COMO, IL


LOCATION.-- Lat 41°46'58", long 89°44'59" (NAD of 1927), in NE1/4NE1/4 sec.25, T.21 N., R.6 E., Whiteside County, Hydrologic Unit 07090005, on left bank, 1 mi upstream from Como, 3 mi downstream from Rock Falls, 3.5 mi upstream from Elkhorn Creek, and at mile 69.2.

DRAINAGE AREA.-- 8,753 mi².

PERIOD OF RECORD.--
SURFACE-WATER DISCHARGE AND STAGE
	DISCHARGE: March to December 1905, October 1914 to September 1971, October 1977 to September 1986. Water years 1987-90, seven-month period (March to September). October 1990 to current year. Published as "at Sterling" 1905-6 and as "at Lyndon" 1914-34. Records published for both sites December 1933 to September 1934. Monthly discharge only for some periods, published in WSP 1308.
	STAGE: Water years 1994 to current year.
	PARTIAL RECORD: Annual maximum, water years 1972-77.
SURFACE-WATER QUALITY
	CHEMICAL: Water years 1978-91.

REVISED RECORDS.-- WSP 1308: 1915(M), 1917-18(M), 1922(M), 1924(M), 1926(M), 1928(M), 1931-32(M), 1934(M). WDR IL-79-1: Drainage area. WDR IL-97-l: 1996 (Dec. 12-23).

GAGE.-- Water-stage recorder, U.S. Army Corps of Engineers satellite telemeter and rain gage, and crest-stage gage. Datum of gage is 606.83 ft above NGVD of 1929. Jan. 6, 1905, to Feb. 17, 1906, nonrecording gage at Sterling, 3 mi upstream, at different datum. Nov. 24, 1914, to Sept. 30, 1934, nonrecording gage at Lyndon, 16.5 mi downstream at datum 22.46 ft lower.

REMARKS.-- Some diurnal fluctuation caused by powerplants upstream from station.

EXTREMES FOR PERIOD OF RECORD.--
SURFACE-WATER DISCHARGE AND STAGE: Maximum discharge, 59,700 ft³/s, Apr. 21, 1973, gage height, 15.66 ft, from rating curve extended above 41,200 ft³/s; maximum gage height, 17.51 ft, Feb. 7, 1938, ice jam; minimum discharge, 390 ft³/s, July 27, 2003, as a result of regulation.

REMARKS FOR CURRENT YEAR.-- Records good except those for estimated daily discharges, which are poor.

Discharge, cubic feet per second, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES
DAY	OCT	NOV	DEC	JAN	FEB	MAR	APR	MAY	JUN	JUL	AUG	SEP

1	4200	4240	3800	3440	e2400	2710	3940	3220	6300	2470	2290	1360
2	3310	4110	3490	3360	e2500	2660	3930	4260	6350	2340	2740	1260
3	5770	4200	3730	3140	e2700	2960	3920	5040	6050	2280	2530	1240
4	5440	4160	3180	2870	3220	2800	4060	6260	5420	2280	2380	1300
5	6330	4240	2920	2790	3720	2630	3140	6780	5190	2690	2350	1310

6	6840	3960	3180	2840	3570	2330	4090	7890	5120	1990	2410	1260
7	6860	4010	2830	2930	3490	2820	3960	8390	5070	2750	2270	1210
8	6170	4070	3370	3040	e3400	2840	3780	7960	4660	3540	2120	1230
9	6140	3490	3890	2880	e3300	2770	3750	7870	4510	3560	2170	1150
10	6140	3620	2820	3110	e3200	2610	3860	8720	4550	4540	2150	1070

11	5280	3940	3080	3360	e3100	2490	3520	9230	4640	4330	2170	1190
12	5240	4130	3360	3180	e3100	2490	3740	10500	4490	4600	2080	1160
13	4440	3980	3780	2620	e3000	2530	3630	9830	4350	3960	1970	1370
14	4440	3860	3270	2590	e3000	2630	3440	10200	4110	3660	1910	1480
15	4110	3720	3310	e2700	3300	2640	3600	10400	4130	3720	1950	1860

16	4380	3810	3520	e2800	3660	2720	3530	10700	4160	5030	2010	2430
17	4050	3890	3370	e3000	3590	3050	3260	10300	4220	5240	1960	2190
18	4120	3710	3320	e3000	3260	3840	3090	9970	4140	4390	1830	1950
19	4200	3800	3580	e3000	2910	4130	2870	9130	4370	3730	1750	2020
20	4190	3840	3550	e2800	2700	4060	2660	9740	4300	3570	1670	2270

21	4030	3710	3870	e2650	2630	4130	2500	9230	4350	3980	1640	2040
22	4100	3720	3830	e2550	2570	4280	2830	8930	4090	3310	1700	1830
23	4070	3710	3750	e2400	3000	3830	3050	8690	3770	3280	1450	1800
24	4180	3760	3640	e2320	2840	3810	3130	8430	4050	3290	1390	1970
25	e4500	3990	3600	e2300	2970	3960	3120	8030	4650	3200	1670	1780

26	e3900	3630	3850	e2200	2900	3530	3410	7560	2160	2860	1360	1660
27	4280	3670	3400	e2200	2860	3890	3460	7040	3010	2570	1420	1710
28	4280	3460	3210	e2250	2790	4080	3480	6700	2530	2800	1470	1800
29	3700	3120	3210	e2150	---	4150	3600	6530	2380	1820	1280	1660
30	3950	3730	3260	e2300	---	4060	3740	6090	2580	2280	1250	1680

31	4430	---	3540	e2300	---	4070	---	6170	---	2250	1320	---

TOTAL	147070	115280	106510	85070	85680	101500	104090	249790	129700	102310	58660	48240
MEAN	4744	3843	3436	2744	3060	3274	3470	8058	4323	3300	1892	1608
MAX	6860	4240	3890	3440	3720	4280	4090	10700	6350	5240	2740	2430
MIN	3310	3120	2820	2150	2400	2330	2500	3220	2160	1820	1250	1070
CFSM	0.54	0.44	0.39	0.31	0.35	0.37	0.40	0.92	0.49	0.38	0.22	0.18
IN.	0.63	0.49	0.45	0.36	0.36	0.43	0.44	1.06	0.55	0.43	0.25	0.21

e Estimated

STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1935 - 2003, BY WATER YEAR (WY)
MEAN	3872	4611	4272	4431	5965	9533	9151	6926	6374	5078	3839	3833
MAX	9633	15900	14120	13200	18020	19970	25070	16660	24500	22030	10820	15630
(WY)	1955	1986	1983	1946	1938	1948	1993	1960	2000	1993	1993	1938
MIN	1210	1408	1411	1047	1353	2432	3305	1652	1848	885	1147	999
(WY)	1964	1950	1964	1940	1940	1968	1958	1958	1936	1936	1936	1958

SUMMARY STATISTICS	FOR 2002 CALENDAR YEAR		FOR 2003 WATER YEAR		WATER YEARS 1935 - 2003
ANNUAL TOTAL	2383470		1333900
ANNUAL MEAN	6530		3655		5690
HIGHEST ANNUAL MEAN					12990	1993
LOWEST ANNUAL MEAN					2187	1964
HIGHEST DAILY MEAN	45200	Jun 5	10700	May 16	45200	A
LOWEST DAILY MEAN	2150	Aug 21	1070	Sep 10	524	Aug 9 1936
ANNUAL SEVEN-DAY MINIMUM	2860	Aug 6	1180	Sep 6	673	Aug 3 1936
MAXIMUM PEAK FLOW			11400	May 12	59700 B	Apr 21 1973
MAXIMUM PEAK STAGE			5.43	May 12	17.51 C	Feb 7 1938
INSTANTANEOUS LOW FLOW			390 D	Jul 27	390 D	Jul 27 2003
ANNUAL RUNOFF (CFSM)	0.75		0.42		0.65
ANNUAL RUNOFF (INCHES)	10.13		5.67		8.83
10 PERCENT EXCEEDS	11000		6070		11000
50 PERCENT EXCEEDS	4940		3410		4300
90 PERCENT EXCEEDS	3310		1830		1700

	A - June 15, 2000 and June 5, 2002.
	B - Gage height, 15.66 ft, from rating curve extended above 41,200 ft/3s.
	C - Ice jam.
	D - As a result of regulation.