LOCATION.-- Lat 40°06'40", long 88°13'35" (NAD of 1927), in NW1/4NE1/4 sec.18, T.19 N., R.9 E., Champaign County, Hydrologic Unit 05120109, on right bank 300 ft. upstream of Mathews Ave. on University of Illinois campus in Urbana, and at mile 1.2. | |
DRAINAGE AREA.-- 4.46 mi2, of which 0.88 mi2 is noncontributing. | |
PERIOD OF RECORD.-- | |
SURFACE-WATER DISCHARGE AND STAGE | |
DISCHARGE: July 1948 to current year. | |
STAGE: Water years 1994 to current year. | |
PRECIPITATION: September 2003 to current year. | |
REVISED RECORDS.-- WDR IL-75-1: Drainage area. WDR IL-83-1: 1982(M). WDR IL-98: 1979-96 (selected events). | |
GAGE.-- Water-stage recorder, phone telemeter, crest-stage gage, unheated tipping-bucket raingage, and concrete control. Datum of gage is 708.10 ft above NGVD of 1929. Prior to Oct. 1, 1974, at datum 0.15 ft higher. | |
REMARKS.-- Since Aug. 1, 1960, storm runoff from 0.88 mi2 at headwaters has been diverted to Saline Branch through the Northwest Diversion Conduit. Prior to the 1970's, effluent from sewage-treatment plant about 0.5 mi upstream from gage. Since July 1999, a retention basin 1.0 mi upstream temporarily detains water during periods of heavy runoff. Water enters the retention basin by gravity flow during periods of heavy runoff, and is pumped out during the recession, with a maximum rate of 20 ft3/s not to exceed a maximum in-stream rate of 60 ft3/s. Since Oct. 1999, some temporary storage occurs in underground conduits 0.6 mi upstream during runoff events. Channel construction near this gage (03337000) began Aug. 30, 2001. Streamflow diversion pumpage for channel construction began Sept. 1, 2001 causing frequent fluctuations in stage. Channel construction and pumpage for channel construction ended May 6, 2003. PRECIPITATION: Collection, computation, and publication of precipitation data do not necessarily conform to standards used by the National Weather Service. Precipitation data could be subject to error for days with freezing and/or thawing of precipitation. | |
EXTREMES FOR PERIOD OF RECORD.-- | |
SURFACE-WATER DISCHARGE AND STAGE: Maximum discharge, 946 ft3/s, from rating based on two indirect measurements, Aug. 12, 1993, gage height, 24.03 ft, present datum, from flood marks; minimum daily, 0.03 ft3/s, Feb. 12, 1981. | |
PRECIPITATION: Maximum daily total, 1.26 in, September 26, 2003. | |
REMARKS FOR CURRENT YEAR.-- Records fair except those for estimated daily discharges, which are poor. | |
| Discharge, cubic feet per second, WATER YEAR OCTOBER 2001 TO SEPTEMBER 2002
DAILY MEAN VALUES | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| DAY | OCT | NOV | DEC | JAN | FEB | MAR | APR | MAY | JUN | JUL | AUG | SEP |
| 1 | 2.0 | e3.6 | e3.3 | 2.4 | e8.9 | e4.0 | e4.9 | e6.0 | e4.4 | e3.1 | e2.8 | e3.0 |
| 2 | 2.0 | e7.5 | e2.8 | 2.4 | e5.2 | e12 | e5.0 | e5.4 | e3.6 | e2.9 | e2.7 | e3.0 |
| 3 | 2.0 | e3.2 | e2.7 | 2.5 | e3.9 | e6.6 | e4.9 | e4.6 | e3.9 | e3.3 | e2.6 | e3.1 |
| 4 | 2.5 | e3.0 | e2.6 | 2.5 | e3.9 | e5.1 | e4.3 | e4.4 | e18 | e3.6 | e2.6 | e2.9 |
| 5 | 21 | e3.0 | e3.3 | 2.4 | e3.5 | e4.8 | e4.4 | e4.2 | e8.5 | e2.9 | e2.6 | e2.9 |
| 6 | 2.7 | e3.2 | e3.6 | 2.6 | e3.4 | e4.8 | e4.1 | e20 | e4.8 | e2.7 | e2.6 | e2.8 |
| 7 | 2.0 | e3.2 | e2.9 | 2.4 | e3.4 | e4.4 | e4.1 | e16 | e4.2 | e2.7 | e2.4 | e2.7 |
| 8 | 2.2 | e3.4 | e2.7 | 2.4 | e3.2 | e3.4 | e14 | e6.0 | e3.4 | e2.9 | e2.4 | e2.6 |
| 9 | 2.1 | e3.2 | e2.5 | 2.4 | e3.0 | e17 | e4.1 | e20 | e2.8 | e3.0 | e2.5 | e2.6 |
| 10 | 12 | e3.1 | 2.2 | 2.4 | e5.1 | e3.2 | e3.4 | e5.4 | e3.2 | e2.8 | e2.4 | e2.6 |
| 11 | 8.7 | e3.1 | 2.3 | 2.4 | e5.0 | e2.8 | e3.0 | e21 | e31 | e2.8 | e2.4 | e2.5 |
| 12 | 18 | e3.1 | 6.7 | 2.4 | e3.4 | e2.7 | e3.3 | e44 | e5.5 | e2.8 | e2.4 | e2.6 |
| 13 | 49 | e3.1 | 5.5 | 2.3 | e2.5 | e2.7 | e3.1 | e11 | e9.5 | e2.8 | e2.4 | e2.7 |
| 14 | 9.2 | e3.0 | 9.6 | 2.0 | e2.4 | e2.7 | e3.2 | e7.3 | e5.4 | e2.8 | e4.6 | e2.6 |
| 15 | 8.4 | e3.0 | 3.3 | 2.0 | e2.4 | e4.7 | e3.3 | e6.4 | e4.4 | e2.8 | e15 | e3.6 |
| 16 | 12 | e3.0 | 8.3 | 2.1 | e2.4 | e5.3 | e2.9 | e25 | e3.6 | e2.8 | e33 | e2.6 |
| 17 | 3.9 | e2.9 | 15 | 2.3 | e2.3 | e5.3 | e3.3 | e9.7 | e3.5 | e2.8 | e4.1 | e6.9 |
| 18 | 3.4 | e3.0 | 4.2 | 2.3 | e2.3 | e4.2 | e3.6 | e6.5 | e3.4 | e3.6 | e3.6 | e3.1 |
| 19 | 3.0 | e2.6 | 3.6 | 2.3 | e49 | e3.7 | e4.0 | e5.8 | e3.3 | e5.9 | e78 | e5.1 |
| 20 | 2.9 | e2.7 | 2.9 | 2.3 | e13 | e3.9 | e4.0 | e5.5 | e3.1 | e3.8 | e13 | e23 |
| 21 | 2.8 | e2.8 | 2.9 | 2.3 | e6.3 | e3.5 | e22 | e5.1 | e3.1 | e2.8 | e3.6 | e2.9 |
| 22 | 2.9 | e2.8 | 4.8 | 2.2 | e5.1 | e3.3 | e4.0 | e4.7 | e3.0 | e5.6 | e44 | e2.7 |
| 23 | 12 | e3.0 | 3.7 | 2.5 | e5.1 | e2.9 | e5.7 | e4.4 | e2.9 | e4.3 | e27 | e2.7 |
| 24 | 29 | e8.8 | 2.7 | 2.9 | e4.8 | e3.2 | e12 | e5.2 | e3.0 | e2.8 | e5.6 | e2.8 |
| 25 | 5.4 | e3.2 | 2.6 | 2.7 | e5.6 | e4.4 | e5.4 | e4.4 | e3.2 | e2.5 | e3.8 | e2.8 |
| 26 | e4.3 | e2.4 | 2.6 | 2.7 | e4.9 | e4.3 | e4.0 | e4.0 | e3.2 | e2.7 | e3.5 | e2.9 |
| 27 | e3.8 | e2.3 | 2.6 | 2.6 | e5.0 | e7.1 | e50 | e4.1 | e2.7 | e5.6 | e3.2 | e2.6 |
| 28 | e3.2 | e6.2 | 2.6 | 2.6 | e4.8 | e9.2 | e8.2 | e13 | e3.2 | e19 | e3.0 | e2.5 |
| 29 | e3.0 | e17 | 2.4 | e10 | --- | e8.0 | e6.6 | e5.3 | e3.2 | e6.4 | e2.9 | e2.5 |
| 30 | e3.4 | e8.8 | 2.4 | e19 | --- | e6.1 | e5.6 | e4.5 | e3.2 | e4.3 | e3.1 | e2.4 |
| 31 | e2.7 | --- | 2.4 | e43 | --- | e5.4 | --- | e4.3 | --- | e2.8 | e3.1 | --- |
| TOTAL | 241.5 | 123.2 | 121.7 | 139.3 | 169.8 | 160.7 | 210.4 | 293.2 | 160.2 | 121.6 | 286.9 | 109.7 |
| MEAN | 7.79 | 4.11 | 3.93 | 4.49 | 6.06 | 5.18 | 7.01 | 9.46 | 5.34 | 3.92 | 9.25 | 3.66 |
| MAX | 49 | 17 | 15 | 43 | 49 | 17 | 50 | 44 | 31 | 19 | 78 | 23 |
| MIN | 2.0 | 2.3 | 2.2 | 2.0 | 2.3 | 2.7 | 2.9 | 4.0 | 2.7 | 2.5 | 2.4 | 2.4 |
| e Estimated |
| STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1949 - 2002, BY WATER YEAR (WY) | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| MEAN | 3.28 | 3.47 | 3.56 | 3.57 | 4.11 | 4.95 | 6.08 | 6.01 | 5.14 | 5.32 | 4.55 | 3.64 |
| MAX | 10.8 | 11.7 | 11.5 | 18.6 | 13.9 | 10.9 | 18.3 | 15.2 | 15.6 | 14.6 | 12.1 | 9.97 |
| (WY) | 1956 | 1986 | 1967 | 1950 | 1982 | 1982 | 1964 | 1990 | 1983 | 1992 | 1993 | 1972 |
| MIN | 1.25 | 1.08 | 0.95 | 0.60 | 1.11 | 0.94 | 1.43 | 1.85 | 1.15 | 1.47 | 1.11 | 0.84 |
| (WY) | 1965 | 1972 | 1990 | 1981 | 1995 | 1981 | 1971 | 1972 | 1988 | 1994 | 1986 | 1983 |
| SUMMARY STATISTICS | FOR 2001 CALENDAR YEAR | FOR 2002 WATER YEAR | WATER YEARS 1949 - 2002 | |||
|---|---|---|---|---|---|---|
| ANNUAL TOTAL | 1711.0 | 2138.2 | ||||
| ANNUAL MEAN | 4.69 | 5.86 | 4.47 | |||
| HIGHEST ANNUAL MEAN | 6.96 | 1950 | ||||
| LOWEST ANNUAL MEAN | 3.00 | 1954 | ||||
| HIGHEST DAILY MEAN | 64 | Feb 24 | 78 A | Aug 19 | 241 | Jun 19 1983 |
| LOWEST DAILY MEAN | 1.3 | Sep 25, 26 | 2.0 | B | 0.03 | Feb 12 1981 |
| ANNUAL SEVEN-DAY MINIMUM | 1.4 | Sep 23 | 2.2 | Jan 13 | 0.05 | Feb 6 1981 |
| MAXIMUM PEAK FLOW | 660 A | Aug 19 | 946 C | Aug 12 1993 | ||
| MAXIMUM PEAK STAGE | 20.10 D | Aug 19 | 24.03 E | Aug 12 1993 | ||
| INSTANTANEOUS LOW FLOW | F | |||||
| 10 PERCENT EXCEEDS | 9.6 | 11 | 9.0 | |||
| 50 PERCENT EXCEEDS | 2.5 | 3.3 | 2.1 | |||
| 90 PERCENT EXCEEDS | 1.8 | 2.4 | 1.0 | |||
|