LOCATION.-- Lat 42°08'18", long 87°50'04" (NAD of 1927), in SW1/4SE1/4 sec.4, T.42 N., R.12 E., Cook County, Hydrologic Unit 07120003, on left bank at upstream side of bridge on State Highway 68 at Northbrook, and at mile 7.9. | |
DRAINAGE AREA.-- 11.5 mi2. | |
PERIOD OF RECORD.-- | |
SURFACE-WATER DISCHARGE AND STAGE | |
DISCHARGE: August 1952 to current year. | |
STAGE: Water years 1994 to current year. | |
GAGE.-- Water-stage recorder, and phone telemeter. Datum of gage is 637.98 ft above NGVD of 1929 (Cook County Highway Department bench mark). | |
REMARKS.-- Effluent from sewage-treatment plant 1.7 mi upstream. | |
EXTREMES FOR PERIOD OF RECORD.-- | |
SURFACE-WATER DISCHARGE AND STAGE: Maximum discharge, 1,190 ft3/s, Aug. 14, 1987, gage height, 10.10 ft; no flow at times in several years. | |
REMARKS FOR CURRENT YEAR.-- Records good except those for estimated daily discharges, which are poor. Effluent from sewage-treatment plant averaged about 4.4 ft3/s. | |
| 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 | 8.4 | 6.5 | 4.7 | 3.4 | 4.0 | e3.3 | 6.5 | 144 | 20 | 5.8 | 9.6 | 8.7 |
| 2 | 19 | 8.2 | 5.8 | 3.6 | 4.0 | 3.3 | 5.7 | 82 | 14 | 5.7 | 7.2 | 7.0 |
| 3 | 9.5 | 7.4 | 5.6 | 3.6 | 4.7 | 3.5 | 8.5 | 37 | 12 | 5.8 | 14 | 5.9 |
| 4 | 35 | 8.2 | 6.1 | 3.5 | 4.6 | 3.8 | 76 | 48 | 9.8 | 15 | 8.3 | 5.4 |
| 5 | 17 | 9.7 | 5.7 | 3.5 | 4.1 | 4.0 | 87 | 140 | 8.1 | 42 | 6.1 | 5.3 |
| 6 | 11 | 7.0 | 5.1 | 3.5 | 3.5 | 4.2 | 25 | 52 | 7.7 | 108 | 4.6 | 4.8 |
| 7 | 8.4 | 6.6 | 4.6 | 3.8 | 3.3 | 4.4 | 21 | 30 | 7.2 | 66 | 4.0 | 4.8 |
| 8 | 7.3 | 7.4 | 4.2 | 3.9 | e3.1 | 5.2 | 25 | 28 | 31 | 39 | 8.0 | 5.8 |
| 9 | 6.2 | 7.0 | 4.9 | 3.8 | 3.0 | 4.4 | 27 | 124 | 15 | 25 | 4.1 | 5.4 |
| 10 | 5.7 | 6.4 | 4.3 | 3.6 | 3.0 | e4.6 | 31 | 83 | 10 | 18 | 3.2 | 5.0 |
| 11 | 5.6 | 8.9 | 3.9 | 3.5 | e2.9 | 4.8 | 22 | 141 | 7.7 | 18 | 3.1 | 5.7 |
| 12 | 5.9 | 5.6 | 3.6 | 3.2 | e2.9 | 8.2 | 17 | 93 | 6.4 | 7.8 | 3.3 | 7.8 |
| 13 | 5.9 | 5.0 | 4.0 | e3.3 | e2.8 | 9.3 | 13 | 66 | 5.9 | 8.4 | 3.2 | 6.3 |
| 14 | 5.4 | 8.1 | 4.0 | 3.3 | e2.8 | 11 | 11 | 54 | 5.4 | 10 | 3.2 | 42 |
| 15 | 5.8 | 9.2 | 3.8 | e3.3 | 2.8 | 13 | 9.6 | 42 | 5.0 | 58 | 3.3 | 12 |
| 16 | 5.2 | 5.8 | 3.8 | e3.3 | e2.8 | 12 | 8.9 | 29 | 4.5 | 16 | 3.0 | 6.1 |
| 17 | 6.4 | 6.5 | 3.7 | e3.2 | e2.8 | 10 | 7.7 | 24 | 4.6 | 33 | 2.8 | 3.5 |
| 18 | 7.4 | 7.8 | 29 | e3.1 | e2.7 | 8.4 | 6.7 | 19 | 10 | 23 | 3.0 | 3.0 |
| 19 | 5.9 | 13 | 15 | e3.0 | 2.7 | 10 | 6.3 | 13 | 9.0 | 11 | 2.6 | 2.8 |
| 20 | 5.3 | 7.5 | 9.0 | 3.0 | e2.7 | 15 | 7.4 | 16 | 6.6 | 15 | 2.5 | 2.2 |
| 21 | 5.3 | 12 | 6.6 | e3.0 | e2.8 | 13 | 7.1 | 14 | 5.9 | 20 | 2.5 | 2.3 |
| 22 | 4.8 | 7.6 | 5.2 | e3.2 | e2.9 | 9.5 | 7.0 | 13 | 5.5 | 8.2 | e2.3 | 7.0 |
| 23 | 5.6 | 7.3 | 5.0 | 3.2 | e2.9 | 8.0 | 6.1 | 14 | 5.6 | 5.4 | e2.3 | 2.9 |
| 24 | 7.7 | 5.8 | 4.7 | e3.2 | e3.0 | 7.8 | 6.4 | 13 | 6.3 | 4.1 | e2.2 | 3.1 |
| 25 | 14 | 6.0 | 4.5 | e3.1 | e3.1 | 13 | 6.3 | 13 | 8.0 | 3.6 | e2.1 | 2.1 |
| 26 | 7.0 | 6.2 | 4.0 | 3.1 | e3.1 | 8.5 | 5.9 | 13 | 6.0 | 3.3 | e5.1 | 14 |
| 27 | 5.6 | 6.8 | 3.8 | e3.1 | e3.1 | 7.4 | 5.9 | 11 | 5.8 | 3.1 | 5.5 | 7.2 |
| 28 | 5.8 | 5.1 | 3.8 | e3.1 | e3.2 | 15 | 5.8 | 57 | 7.7 | 3.6 | 5.6 | 3.9 |
| 29 | 5.6 | 6.8 | 3.8 | e3.0 | --- | 12 | 5.6 | 50 | 8.8 | 3.6 | 5.3 | 3.9 |
| 30 | 5.5 | 5.3 | 3.9 | 3.0 | --- | 8.3 | 24 | 29 | 6.8 | 3.5 | 5.9 | 4.0 |
| 31 | 5.4 | --- | 4.1 | e3.5 | --- | 6.9 | --- | 35 | --- | 3.8 | 6.8 | --- |
| TOTAL | 258.6 | 220.7 | 180.2 | 102.9 | 89.3 | 251.8 | 502.4 | 1527 | 266.3 | 592.7 | 144.7 | 199.9 |
| MEAN | 8.34 | 7.36 | 5.81 | 3.32 | 3.19 | 8.12 | 16.7 | 49.3 | 8.88 | 19.1 | 4.67 | 6.66 |
| MAX | 35 | 13 | 29 | 3.9 | 4.7 | 15 | 87 | 144 | 31 | 108 | 14 | 42 |
| MIN | 4.8 | 5.0 | 3.6 | 3.0 | 2.7 | 3.3 | 5.6 | 11 | 4.5 | 3.1 | 2.1 | 2.1 |
| CFSM | 0.73 | 0.64 | 0.51 | 0.29 | 0.28 | 0.71 | 1.46 | 4.28 | 0.77 | 1.66 | 0.41 | 0.58 |
| IN. | 0.84 | 0.71 | 0.58 | 0.33 | 0.29 | 0.81 | 1.63 | 4.94 | 0.86 | 1.92 | 0.47 | 0.65 |
| e Estimated |
| STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1952 - 2003, BY WATER YEAR (WY) | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| MEAN | 9.28 | 11.0 | 11.7 | 9.84 | 14.3 | 22.7 | 25.2 | 17.0 | 14.5 | 11.3 | 11.0 | 10.4 |
| MAX | 59.4 | 40.4 | 51.2 | 40.0 | 43.2 | 86.6 | 57.3 | 67.3 | 41.6 | 59.2 | 57.5 | 50.0 |
| (WY) | 2002 | 1986 | 1983 | 1974 | 1997 | 1979 | 1983 | 1996 | 1978 | 1982 | 1987 | 1986 |
| MIN | 0.24 | 0.34 | 0.54 | 0.38 | 1.04 | 3.01 | 6.58 | 4.61 | 1.51 | 0.50 | 0.47 | 0.24 |
| (WY) | 1954 | 1957 | 1954 | 1954 | 1963 | 1956 | 1953 | 1953 | 1956 | 1956 | 1955 | 1952 |
| SUMMARY STATISTICS | FOR 2002 CALENDAR YEAR | FOR 2003 WATER YEAR | WATER YEARS 1952 - 2003 | |||
|---|---|---|---|---|---|---|
| ANNUAL TOTAL | 5299.6 | 4336.5 | ||||
| ANNUAL MEAN | 14.5 | 11.9 | 14.0 | |||
| HIGHEST ANNUAL MEAN | 22.5 | 1993 | ||||
| LOWEST ANNUAL MEAN | 2.96 | 1953 | ||||
| HIGHEST DAILY MEAN | 306 | Aug 22 | 144 | May 1 | 753 | Aug 14 1987 |
| LOWEST DAILY MEAN | 2.5 | Aug 3 | 2.1 | A | 0.00 | B |
| ANNUAL SEVEN-DAY MINIMUM | 2.8 | Aug 6 | 2.4 | Aug 19 | 0.00 | Oct 27 1956 |
| MAXIMUM PEAK FLOW | 369 | Jul 6 | 1190 | Aug 14 1987 | ||
| MAXIMUM PEAK STAGE | 5.66 | Jul 6 | 10.10 | Aug 14 1987 | ||
| INSTANTANEOUS LOW FLOW | 1.1 | Sep 25 | ||||
| ANNUAL RUNOFF (CFSM) | 1.26 | 1.03 | 1.22 | |||
| ANNUAL RUNOFF (INCHES) | 17.14 | 14.03 | 16.56 | |||
| 10 PERCENT EXCEEDS | 28 | 25 | 29 | |||
| 50 PERCENT EXCEEDS | 7.5 | 5.9 | 6.1 | |||
| 90 PERCENT EXCEEDS | 3.9 | 3.0 | 2.0 | |||