05437500 DATA: Discharge Tables, 2001

ROCK RIVER BASIN

05437500 ROCK RIVER AT ROCKTON, IL

LOCATION.-- Lat 42°26'55", long 89°04'11", in SW1/4NE1/4 sec.24, T.46 N., R.1 E., Winnebago County, Hydrologic Unit 07090005, on right bank 750 ft downstream from State Highway 75 in Rockton, 1.0 mi downstream from Pecatonica River, and at mile 156.1.

DRAINAGE AREA.-- 6,363 mi².

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

DISCHARGE: June 1903 to July 1906, October 1906 to March 1909, July 1914 to September 1919, October 1939 to current year. Published as "below mouth of Pecatonica River at Rockton" 1903-9; as "at Rockford" 1914-19. Monthly discharge only for some periods for 1903-1950, published in WSP 1308.

STAGE: Water years 1994-2001.

SURFACE-WATER QUALITY

CHEMICAL: Water years 1978-91.

REVISED RECORDS.-- WSP 325: 1903-9. WSP 895: 1904(M). WSP 1508: 1915, 1916-17(M). WDR IL-75-1: Drainage area. WDR IL-97-1: 1996 (Dec. 10-23).

GAGE.-- Water-stage recorder, U.S. Army Corps of Engineers satellite telemeter and raingage, and crest-stage gage. Datum of gage is 707.94 ft above sea level (levels by U.S. Army Corps of Engineers). Prior to Oct. 1, 1906, nonrecording gage at site 800 ft upstream at datum about 1 ft higher. Oct. 1, 1906, to Mar. 31, 1909, nonrecording gage at site 800 ft upstream at datum about 2 ft higher. July 30, 1914, to Apr. 30, 1919, nonrecording gage at site at Rockford about 21 mi downstream, at different datum. Oct. 1, 1939, to Aug. 10, 1973, at site 800 ft upstream at same datum.

REMARKS.-- Low flow regulated by power-plant upstream from station.

EXTREMES FOR PERIOD OF RECORD.--
SURFACE-WATER DISCHARGE AND STAGE: Maximum discharge, 32,500 ft³/s, Mar. 30, 1916, gage height, 13.06 ft, site and datum then in use; minimum daily, 501 ft³/s, Sept. 14, 1958.

EXTREMES OUTSIDE PERIOD OF RECORD.--
SURFACE-WATER DISCHARGE AND STAGE: Flood in February 1937 reached a stage of 14.6 ft (backwater from ice), from floodmark.

REMARKS FOR CURRENT YEAR.-- Records good except those for October 1 to August 30, which are fair and those for estimated daily discharges, which are poor.

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	4170	3490	3850	e2860	e3220	8840	7460	7610	6260	7470	2970	3490
2	3970	3320	3830	e2940	e3400	8650	7190	7390	6570	7430	3820	3310
3	3880	3160	3750	e3000	e3550	9150	7200	7520	6640	7170	4350	3170
4	4210	3080	3730	e3000	e3580	9280	7210	8320	6570	7010	4440	3340
5	4300	3050	3610	e3000	e3580	7900	7130	8950	6970	6760	4940	3490

6	3690	3160	3060	e3000	e3700	7280	7160	9200	7540	6520	4730	3180
7	3230	3810	3000	e3100	4040	6890	7130	9060	7600	6300	4570	3410
8	3240	3770	3390	e3250	4390	6600	6660	8660	7700	6140	4480	4330
9	3110	4340	3070	e3350	6240	6350	7560	8270	7500	5990	3890	5060
10	3070	4630	3270	e3450	7590	6180	8140	8200	7240	5590	3670	5580

11	2950	4680	2800	e3280	7970	6390	8470	8750	6910	4940	3770	5820
12	2870	4580	2960	e3260	8240	6920	9720	8770	7700	4680	3430	6050
13	2810	4440	e3800	e3260	8190	7530	10200	8120	8310	4630	3520	5880
14	2850	4400	e3800	e3280	8540	7870	10500	8050	7830	4250	3200	5570
15	2790	4300	e3600	e3300	8530	8370	10500	7920	8370	4040	2590	5250

16	2800	4300	e3210	e3280	8340	9250	10300	7590	8680	3740	3410	5020
17	3010	3960	e3100	e3270	7930	9270	9990	7220	8670	3440	3440	4870
18	3540	3860	e3000	e3270	7610	9380	9820	6900	8680	3430	3300	4820
19	3670	3920	e3000	e3270	7200	9480	9410	6590	8540	3520	3440	5310
20	3600	3930	e2950	e3300	6860	9560	9360	6290	8670	3530	3520	5690

21	3460	3850	e2900	e3400	6450	9740	9310	6420	8690	3640	3220	6340
22	3350	3880	e2860	e3490	6190	9600	9270	6930	8550	3640	3180	7050
23	3380	3910	e2800	e3500	5990	9490	9480	7190	8490	3580	3380	7440
24	3370	4000	e2780	e3450	6070	9330	9130	7420	8330	3370	3580	8070
25	3750	4080	e2800	e3400	8050	9180	9240	7430	8160	3490	3640	7790

26	3870	4150	e2800	e3380	8870	9040	9020	7370	8050	3550	3950	7370
27	3800	4100	e2780	e3300	8970	8880	8750	7140	7980	3660	4140	7380
28	3760	3900	e2740	e3250	9020	8630	8580	6960	8000	3560	4380	7310
29	3720	3850	e2790	e3250	---	8060	8190	6780	7800	3150	4960	6990
30	3630	3820	e2810	e3220	---	8000	7780	6470	7660	3500	4470	6430

31	3560	---	e2820	e3180	---	7740	---	6260	---	2800	3840	---

TOTAL	107410	117720	97660	100540	182310	258830	259860	235750	234660	144520	118220	164810
MEAN	3465	3924	3150	3243	6511	8349	8662	7605	7822	4662	3814	5494
MAX	4300	4680	3850	3500	9020	9740	10500	9200	8690	7470	4960	8070
MIN	2790	3050	2740	2860	3220	6180	6660	6260	6260	2800	2590	3170
CFSM	.54	.62	.50	.51	1.02	1.31	1.36	1.20	1.23	.73	.60	.86
IN.	.63	.69	.57	.59	1.07	1.51	1.52	1.38	1.37	.84	.69	.96

e Estimated

STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1940 - 2001, BY WATER YEAR (WY)
MEAN	3088	3498	3260	3210	3887	7273	7365	5368	4523	3716	2899	2913
MAX	13340	11320	9049	9432	8365	13920	18530	17770	16960	17000	9039	7753
(WY)	1987	1986	1983	1960	1997	1974	1993	1973	2000	1993	1993	1972
MIN	857	1100	1004	800	1000	1692	2476	1103	1248	1056	793	780
(WY)	1965	1940	1959	1940	1940	1954	1958	1958	1977	1965	1958	1958

SUMMARY STATISTICS	FOR 2000 CALENDAR YEAR		FOR 2001 WATER YEAR		WATER YEARS 1940 - 2001
ANNUAL TOTAL	2006180		2022290
ANNUAL MEAN	5481		5541		4249
HIGHEST ANNUAL MEAN					9484	1993
LOWEST ANNUAL MEAN					1568	1958
HIGHEST DAILY MEAN	22200	Jun 14	10500	Apr 14,15	29700	Mar 25 1975
LOWEST DAILY MEAN	2000 A	Feb 4	2590	Aug 15	501	Sep 14 1958
ANNUAL SEVEN-DAY MINIMUM	2110 A	Jan 31	2780 A	Dec 23	622	Oct 2 1958
MAXIMUM PEAK FLOW			10700	Apr 12	30000	Mar 25 1975
MAXIMUM PEAK STAGE			7.62	Apr 12	15.54	Mar 25 1975
INSTANTANEOUS LOW FLOW			1900	Aug 15
ANNUAL RUNOFF (CFSM)	.86		.87		.67
ANNUAL RUNOFF (INCHES)	11.73		11.82		9.07
10 PERCENT EXCEEDS	10000		8800		8410
50 PERCENT EXCEEDS	4020		4580		3210
90 PERCENT EXCEEDS	2780		3070		1300

A - Estimated due to backwater from ice.

Table of Contents

Introduction

Station Descriptions

Surface-Water Data

Ground-Water Data

Meteorological Data

Biological Data