05437500 DATA: Discharge Tables, 2000

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 1994-2000.

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 fair except those for estimated daily discharges, which are poor.

DISCHARGE, IN CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1999 TO SEPTEMBER 2000 DAILY MEAN VALUES
DAY	OCT	NOV	DEC	JAN	FEB	MAR	APR	MAY	JUN	JUL	AUG	SEP

1	4550	2960	2800	e2400	e2200	8920	3770	4750	14000	8440	4850	3350
2	4370	2920	2720	e2500	e2100	8820	3710	4560	18200	8110	4670	3320
3	4240	2920	2980	e2600	e2050	8450	3700	4410	19900	10100	4530	3300
4	4230	2880	3160	e2650	e2000	7610	3550	4360	20600	9620	4450	3280
5	4100	2860	3660	e2700	e2050	6930	3460	4050	20900	9240	4360	3270

6	3950	2740	3710	2740	e2100	6490	3570	4050	20800	8960	4870	3160
7	4010	2520	3620	2920	e2300	6260	3690	3910	20400	8650	4720	3080
8	3880	2550	3660	2880	2560	6100	3440	3820	20200	8170	5120	3040
9	3530	2930	3670	2890	2630	5900	3250	4100	20000	7790	5430	2990
10	3460	2870	3760	2990	2660	5870	3270	4590	19600	8450	5230	3000

11	3370	2910	3700	3110	2680	5730	3360	4810	18800	8840	5130	3100
12	3260	2880	3720	3220	2650	5560	3210	4860	19400	8430	4620	4630
13	3250	2860	3640	3230	2600	5380	2970	4660	21500	8270	4270	5320
14	3300	2900	3880	2930	2610	5270	3000	4400	22200	8010	4170	5480
15	3130	2970	3990	2900	2600	5280	2980	4240	22000	7610	4050	5700

16	3490	3050	3860	3100	2580	5260	3130	4450	21400	7150	3940	5400
17	3450	2930	3770	3120	2590	5200	3190	4450	20200	6760	3830	4910
18	3480	2510	3440	3050	2600	4920	3070	5200	18900	6410	3720	4490
19	3510	2510	3340	3070	2620	4700	3250	7900	17500	6190	3710	4190
20	3400	2310	3150	2840	2730	4660	4770	9430	16200	5980	3750	3870

21	3300	2570	2570	2800	2760	4570	7110	9980	14900	5770	3760	3750
22	3290	2580	e2600	3100	2830	4550	6750	10600	13600	5420	3690	4080
23	3200	2700	e2500	e2900	3500	4480	6700	10900	12900	5180	3650	6150
24	3170	2790	e2400	e2800	5150	4590	6570	10900	12300	4990	3660	7110
25	3100	2910	e2300	e2700	6470	4540	6560	10100	11800	4910	3600	6930

26	3070	2960	e2250	e2600	7480	4290	6140	9770	11200	4510	3560	6990
27	3050	2980	e2200	e2500	8150	4280	5570	9820	10600	4230	3560	6100
28	3040	2970	e2200	e2450	8440	4190	5210	10200	10100	4350	3490	5290
29	3010	2930	e2200	e2400	8770	4140	5120	10200	9570	4230	3310	4750
30	2990	2890	e2300	e2300	---	4110	4840	9850	9020	4210	3430	4400

31	3000	---	e2350	e2250	---	3970	---	10100	---	4310	3400	---

TOTAL	108180	84260	96100	86640	102460	171020	128910	209420	508690	213290	128530	134430
MEAN	3490	2809	3100	2795	3533	5517	4297	6755	16960	6880	4146	4481
MAX	4550	3050	3990	3230	8770	8920	7110	10900	22200	10100	5430	7110
MIN	2990	2310	2200	2250	2000	3970	2970	3820	9020	4210	3310	2990
CFSM	.55	.44	.49	.44	.56	.87	.68	1.06	2.66	1.08	.65	.70
IN.	.63	.49	.56	.51	.60	1.00	.75	1.22	2.97	1.25	.75	.79

e Estimated

STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1940 - 2000, BY WATER YEAR (WY)
MEAN	3081	3491	3262	3210	3844	7256	7344	5331	4469	3701	2884	2870
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 1999 CALENDAR YEAR		FOR 2000 WATER YEAR		WATER YEARS 1940 - 2000
ANNUAL TOTAL	2067230		1971930
ANNUAL MEAN	5664		5388		4228
HIGHEST ANNUAL MEAN					9484	1993
LOWEST ANNUAL MEAN					1568	1958
HIGHEST DAILY MEAN	15600	Apr 29	22200	Jun 14	29700	Mar 25 1975
LOWEST DAILY MEAN	1900 A	Jan 17-19	2000 A	Feb 4	501	Sep 14 1958
ANNUAL SEVEN-DAY MINIMUM	1970 A	Jan 13	2110 A	Jan 31	622	Oct 2 1958
INSTANTANEOUS PEAK FLOW			22500	Jun 14	30000	Mar 25 1975
INSTANTANEOUS PEAK STAGE			12.66	Jun 14	15.54	Mar 25 1975
INSTANTANEOUS LOW FLOW			1860	Nov 18
ANNUAL RUNOFF (CFSM)	.89		.85		.66
ANNUAL RUNOFF (INCHES)	12.09		11.53		9.03
10 PERCENT EXCEEDS	10400		10000		8400
50 PERCENT EXCEEDS	4910		3860		3180
90 PERCENT EXCEEDS	2500		2600		1300

A - Estimated due to backwater from ice.

Table of Contents

Introduction

Station Descriptions

Surface-Water Data

Ground-Water Data

Meteorological Data

Biological Data