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 1994-2002. | |
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 March 26 to June 14, which are fair, and those for estimated daily discharges, which are poor. Effluent from sewage-treatment plant averaged about 3.5 ft3/s. | |
| 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 | 24 | 18 | 17 | e3.7 | 19 | 9.2 | 12 | 34 | 11 | 4.6 | 2.9 | 3.0 |
| 2 | 9.8 | 14 | 12 | e3.7 | 13 | 14 | 15 | 76 | 8.1 | 5.0 | 2.7 | 65 |
| 3 | 8.8 | 7.4 | 9.6 | e3.8 | 10 | 17 | 11 | 28 | 32 | 4.9 | 2.5 | 30 |
| 4 | 17 | 6.9 | 8.2 | e3.9 | 8.9 | e21 | 10 | 16 | 209 | 3.9 | 6.9 | 20 |
| 5 | 23 | 15 | 7.4 | 4.0 | 8.2 | e14 | 9.2 | 14 | 88 | 4.0 | 7.4 | 12 |
| 6 | 9.5 | 12 | 8.3 | 4.2 | 6.8 | e13 | 8.2 | 13 | 36 | 6.4 | 3.3 | 6.9 |
| 7 | 6.8 | 11 | 6.9 | 4.4 | 8.3 | 17 | 16 | 12 | 24 | 4.6 | 2.7 | 5.7 |
| 8 | 6.7 | 11 | 6.2 | 4.3 | 11 | 88 | 60 | 12 | 25 | 4.9 | 2.6 | 5.0 |
| 9 | 16 | 11 | 5.4 | 4.3 | 16 | 107 | 103 | 17 | 24 | 20 | 2.7 | 5.2 |
| 10 | 9.5 | 11 | 5.4 | 4.4 | 32 | e45 | 39 | 16 | 16 | 6.2 | 2.7 | 5.2 |
| 11 | 9.7 | 9.7 | 5.0 | 4.3 | 23 | 25 | 26 | 42 | 18 | 4.8 | 2.7 | 5.1 |
| 12 | 55 | 6.7 | 6.4 | 4.3 | 17 | 22 | 21 | 138 | 23 | 4.2 | 3.0 | 4.7 |
| 13 | 275 | 6.6 | 32 | 4.2 | 14 | 20 | 17 | 48 | 22 | 3.7 | 73 | 4.5 |
| 14 | 167 | 6.7 | 15 | 4.8 | 12 | 17 | 15 | 31 | 19 | 3.4 | 24 | 4.3 |
| 15 | 84 | 5.2 | 11 | 4.8 | 12 | 12 | 14 | 29 | 13 | 3.5 | 8.3 | 4.4 |
| 16 | 53 | 4.8 | 13 | 5.1 | 12 | 9.6 | 12 | 75 | 9.3 | 4.0 | 5.7 | 4.5 |
| 17 | 61 | 4.3 | 13 | 5.7 | 10 | 8.6 | 15 | 64 | 8.7 | 4.0 | 4.0 | 4.6 |
| 18 | 75 | 4.4 | 11 | 4.8 | 9.2 | 8.3 | 13 | 37 | 6.0 | 4.2 | 3.1 | 11 |
| 19 | 75 | 6.8 | 15 | 4.6 | 23 | 7.5 | 12 | 36 | 4.3 | 5.2 | 7.9 | 47 |
| 20 | 45 | 4.8 | 12 | 4.1 | 55 | 8.4 | 12 | 26 | 4.9 | 3.1 | 4.2 | 30 |
| 21 | 41 | 4.6 | 9.7 | 4.6 | 36 | 7.9 | 13 | 23 | 4.4 | 3.1 | 25 | 14 |
| 22 | 51 | 4.3 | 10 | 4.3 | 23 | 7.2 | 18 | 18 | 4.3 | 5.6 | 306 | 38 |
| 23 | 205 | 4.2 | 12 | 5.0 | 17 | 6.4 | 15 | 16 | 3.7 | 3.2 | 44 | 13 |
| 24 | 145 | 11 | 8.6 | 5.8 | 14 | 6.1 | 14 | 15 | 3.3 | e12 | 19 | 8.4 |
| 25 | 104 | 14 | 6.9 | 5.3 | 13 | 5.8 | 14 | 15 | 3.6 | 3.4 | 11 | 6.8 |
| 26 | 84 | 7.7 | 6.2 | 4.8 | 13 | 6.1 | 13 | 15 | 5.2 | 7.9 | 18 | 6.4 |
| 27 | 45 | 6.4 | e5.4 | 4.8 | 12 | 6.0 | 13 | 14 | 4.4 | 5.9 | 20 | 6.0 |
| 28 | 40 | 5.8 | e4.5 | 6.4 | 11 | 5.4 | 26 | 14 | 4.4 | 3.0 | 15 | 5.3 |
| 29 | 44 | 10 | e4.2 | 6.9 | --- | 29 | 25 | 14 | 3.9 | 6.5 | 14 | 31 |
| 30 | 34 | 32 | e3.9 | 5.1 | --- | 18 | 21 | 14 | 4.1 | 4.6 | 15 | 11 |
| 31 | 18 | --- | e3.8 | 10 | --- | 12 | --- | 13 | --- | 3.4 | 6.3 | --- |
| TOTAL | 1841.8 | 277.3 | 295.0 | 150.4 | 459.4 | 593.5 | 612.4 | 935 | 642.6 | 163.2 | 665.6 | 418.0 |
| MEAN | 59.41 | 9.243 | 9.516 | 4.852 | 16.41 | 19.15 | 20.41 | 30.16 | 21.42 | 5.265 | 21.47 | 13.93 |
| MAX | 275 | 32 | 32 | 10 | 55 | 107 | 103 | 138 | 209 | 20 | 306 | 65 |
| MIN | 6.7 | 4.2 | 3.8 | 3.7 | 6.8 | 5.4 | 8.2 | 12 | 3.3 | 3.0 | 2.5 | 3.0 |
| CFSM | 5.17 | 0.80 | 0.83 | 0.42 | 1.43 | 1.66 | 1.78 | 2.62 | 1.86 | 0.46 | 1.87 | 1.21 |
| IN. | 5.96 | 0.90 | 0.95 | 0.49 | 1.49 | 1.92 | 1.98 | 3.02 | 2.08 | 0.53 | 2.15 | 1.35 |
| e Estimated |
| STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1952 - 2002, BY WATER YEAR (WY) | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| MEAN | 9.301 | 11.08 | 11.86 | 9.973 | 14.52 | 22.97 | 25.38 | 16.33 | 14.57 | 11.14 | 11.11 | 10.51 |
| 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 2001 CALENDAR YEAR | FOR 2002 WATER YEAR | WATER YEARS 1952 - 2002 | |||
|---|---|---|---|---|---|---|
| ANNUAL TOTAL | 8133.6 | 7054.2 | ||||
| ANNUAL MEAN | 22.28 | 19.33 | 14.06 | |||
| HIGHEST ANNUAL MEAN | 22.5 | 1993 | ||||
| LOWEST ANNUAL MEAN | 2.96 | 1953 | ||||
| HIGHEST DAILY MEAN | 337 A | Sep 19 | 306 | Aug 22 | 753 | Aug 14 1987 |
| LOWEST DAILY MEAN | 2.7 | Jul 15 | 2.5 | Aug 3 | 0.00 | B |
| ANNUAL SEVEN-DAY MINIMUM | 3.3 | Jul 10 | 2.8 | Aug 6 | 0.00 | Oct 27 1956 |
| MAXIMUM PEAK FLOW | 848 | Oct 13 | 1190 | Aug 14 1987 | ||
| MAXIMUM PEAK STAGE | 8.77 | Oct 13 | 10.10 | Aug 14 1987 | ||
| INSTANTANEOUS LOW FLOW | 1.2 | Aug 3 | ||||
| ANNUAL RUNOFF (CFSM) | 1.94 | 1.68 | 1.22 | |||
| ANNUAL RUNOFF (INCHES) | 26.31 | 22.82 | 16.61 | |||
| 10 PERCENT EXCEEDS | 45 | 40 | 30 | |||
| 50 PERCENT EXCEEDS | 11 | 10 | 6.1 | |||
| 90 PERCENT EXCEEDS | 4.6 | 4.0 | 1.9 | |||