05437500 DATA: Discharge Tables, 2002

ROCK RIVER BASIN

05437500 ROCK RIVER AT ROCKTON, IL


LOCATION.-- Lat 42°26'55", long 89°04'11" (NAD of 1927), 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 November 1907, January 1908 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 1994-2002.
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 NGVD of 1929 (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 estimated daily discharges, which are poor.

DISCHARGE, in CFS, WATER YEAR OCTOBER 2001 TO SEPTEMBER 2002 DAILY MEAN VALUES
DAY	OCT	NOV	DEC	JAN	FEB	MAR	APR	MAY	JUN	JUL	AUG	SEP

1	6030	6540	5620	e4100	4170	5890	5980	6940	4750	4700	2540	2900
2	5740	6460	5450	e4050	3990	5870	6050	6950	4630	4200	2520	3050
3	5410	6300	5430	e4000	3950	5550	5970	6740	4800	4040	2430	2820
4	5240	6160	5410	e4000	3800	4970	5860	6680	7150	3690	2550	2960
5	5070	6030	5310	e4000	3400	5000	5710	6550	9730	3500	2520	3160

6	4900	5830	5150	e4000	3520	5350	5560	6470	9980	3400	2540	3050
7	4720	5600	5270	e4000	3770	5640	5530	6410	10400	3420	2470	2850
8	4600	5440	5300	e3950	3800	5720	6190	6360	11000	3280	2430	2670
9	4380	5350	5240	e3900	3840	6930	8220	6210	11800	3050	2360	2510
10	4500	5200	5150	e3800	4470	7700	9090	5890	11800	3310	2190	2490

11	4700	5100	5110	3690	4390	7820	9340	6170	11500	3110	2140	2460
12	4780	5010	5060	e3750	4490	8630	9880	6420	11000	3110	2280	2410
13	4940	5070	5290	3840	4540	8650	9970	6490	10600	2780	2440	2370
14	4960	5300	5340	3900	4380	8770	9700	6350	10300	2620	2490	2280
15	4750	5340	5370	4100	4300	8510	9100	6330	9850	2800	2900	2270

16	4750	5560	5500	4050	4280	8060	8560	6240	9370	2770	2860	2290
17	4670	5490	5580	3930	4140	7920	8190	6270	8730	2660	2480	2270
18	4570	5310	5550	3690	4040	7830	7920	6170	8170	2630	2160	2210
19	4600	5160	5520	3610	4150	7630	7820	6120	7810	2750	2210	2230
20	4500	5010	5400	3750	4710	7340	7770	5960	7320	2650	2290	2680

21	4450	4880	5610	3790	5530	7080	7710	5800	7040	2550	2230	2680
22	4570	4830	5550	3900	6080	6830	7600	5580	6880	2720	4010	2640
23	5840	4770	5400	4000	6460	6740	7390	5430	6450	2650	5940	2560
24	7340	5090	5240	4020	6590	6820	7360	5320	6140	2750	6090	2440
25	7880	5500	4770	3940	6660	6900	7080	5400	5830	2640	6250	2420

26	7770	5590	4340	3890	6380	6620	6950	5300	5700	2650	6410	2430
27	8240	6030	4510	3920	6290	6370	7000	4940	5480	2630	6540	2420
28	8040	5980	4670	3960	5980	6270	7200	5370	5280	2480	6670	2420
29	7620	5930	4590	3980	---	6180	7150	5160	5060	2630	6270	2580
30	7260	5820	e4250	3860	---	6160	6880	5030	4910	2620	4670	2730

31	6860	---	e4150	3970	---	6010	---	4820	---	2550	3420	---

TOTAL	173680	165680	160130	121340	132100	211760	224730	185870	239460	93340	107300	77250
MEAN	5603	5523	5165	3914	4718	6831	7491	5996	7982	3011	3461	2575
MAX	8240	6540	5620	4100	6660	8770	9970	6950	11800	4700	6670	3160
MIN	4380	4770	4150	3610	3400	4970	5530	4820	4630	2480	2140	2210
CFSM	0.88	0.87	0.81	0.62	0.74	1.07	1.18	0.94	1.25	0.47	0.54	0.40
IN.	1.02	0.97	0.94	0.71	0.77	1.24	1.31	1.09	1.40	0.55	0.63	0.45

e Estimated

STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1940 - 2002, BY WATER YEAR (WY)
MEAN	3127	3530	3290	3222	3900	7266	7367	5378	4578	3705	2908	2907
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 2001 CALENDAR YEAR		FOR 2002 WATER YEAR		WATER YEARS 1940 - 2002
ANNUAL TOTAL	2198990		1892640
ANNUAL MEAN	6025		5185		4264
HIGHEST ANNUAL MEAN					9484	1993
LOWEST ANNUAL MEAN					1568	1958
HIGHEST DAILY MEAN	10500	Apr 14,15	11800	Jun 9,10	29700	Mar 25 1975
LOWEST DAILY MEAN	2590	Aug 15	2140	Aug 11	501	Sep 14 1958
ANNUAL SEVEN-DAY MINIMUM	2990	Jan 1	2270	Sep 13	622	Oct 2 1958
MAXIMUM PEAK FLOW			12700	Jun 9	30000	Mar 25 1975
MAXIMUM PEAK STAGE			8.52	Jun 9	15.54	Mar 25 1975
INSTANTANEOUS LOW FLOW			1980	Aug 18
ANNUAL RUNOFF (CFSM)	0.95		0.81		0.67
ANNUAL RUNOFF (INCHES)	12.86		11.06		9.11
10 PERCENT EXCEEDS	8800		7810		8400
50 PERCENT EXCEEDS	5820		5150		3240
90 PERCENT EXCEEDS	3350		2550		1310

Table of Contents

Introduction

Station Descriptions

Surface-Water Data

Ground-Water Data

Meteorological Data

Biological Data