Observed and urbanization-adjusted annual maximum peak discharge and associated urban fraction and precipitation values at USGS streamgage:
05533400 SAWMILL CREEK NEAR LEMONT, IL
| Water year | Segment | Discharge code | Cumulative reservoir storage (acre-feet) | Urban fraction | Precipitation (inches) | Observed peak discharge (ft3/s) | Adjusted peak discharge (ft3/s) | Exceedance probability |
| 1961 | 1 | -- | 0 | 0.336 | 2.618 | 924 | 1340 | 0.039 |
| 1962 | 1 | -- | 0 | 0.359 | 0.414 | 195 | 367 | 0.864 |
| 1963 | 1 | -- | 0 | 0.382 | 1.376 | 59 | 148 | 1.000 |
| 1964 | 1 | 4B | 0 | 0.405 | 0.214 | 156 | 300 | 0.933 |
| 1965 | 1 | 4B | 0 | 0.428 | 0.214 | 395 | 593 | 0.504 |
| 1966 | 1 | -- | 0 | 0.451 | 3.992 | 984 | 1300 | 0.043 |
| 1967 | 1 | -- | 0 | 0.474 | 1.180 | 725 | 967 | 0.127 |
| 1968 | 1 | -- | 0 | 0.497 | 2.979 | 472 | 649 | 0.420 |
| 1969 | 1 | -- | 0 | 0.520 | 1.690 | 541 | 713 | 0.323 |
| 1970 | 1 | -- | 0 | 0.543 | 1.198 | 279 | 394 | 0.827 |
| 1971 | 1 | 4B | 0 | 0.555 | 0.214 | 385 | 510 | 0.643 |
| 1972 | 1 | -- | 0 | 0.567 | 3.178 | 883 | 1080 | 0.084 |
| 1973 | 1 | -- | 0 | 0.580 | 0.793 | 718 | 872 | 0.176 |
| 1974 | 1 | -- | 0 | 0.592 | 1.567 | 654 | 790 | 0.233 |
| 1975 | 1 | -- | 0 | 0.604 | 2.244 | 984 | 1160 | 0.065 |
| 1976 | 1 | -- | 0 | 0.617 | 0.940 | 970 | 1130 | 0.070 |
| 1977 | 1 | -- | 0 | 0.629 | 2.422 | 535 | 638 | 0.437 |
| 1978 | 1 | -- | 0 | 0.642 | 1.962 | 835 | 956 | 0.133 |
| 1979 | 1 | -- | 0 | 0.654 | 1.101 | 916 | 1040 | 0.097 |
| 1986 | 1 | -- | 0 | 0.693 | 1.513 | 494 | 553 | 0.569 |
| 1987 | 1 | -- | 0 | 0.697 | 3.726 | 560 | 621 | 0.463 |
| 1988 | 1 | -- | 0 | 0.701 | 0.873 | 396 | 444 | 0.754 |
| 1989 | 1 | -- | 0 | 0.706 | 2.066 | 912 | 985 | 0.120 |
| 1990 | 1 | -- | 0 | 0.710 | 3.153 | 1730 | 1840 | 0.015 |
| 1991 | 1 | -- | 0 | 0.712 | 3.446 | 1260 | 1340 | 0.038 |
| 1992 | 1 | DE | 0 | 0.715 | 0.214 | 241 | 276 | 0.949 |
| 1993 | 1 | -- | 0 | 0.717 | 3.031 | 1600 | 1690 | 0.018 |
| 1994 | 1 | -- | 0 | 0.719 | 1.599 | 526 | 570 | 0.541 |
| 1995 | 1 | -- | 0 | 0.721 | 0.999 | 456 | 496 | 0.669 |
| 1996 | 1 | C | 0 | 0.723 | 5.870 | 3070 | 3210 | 0.000 |
| 1997 | 1 | C | 0 | 0.726 | 2.798 | 1360 | 1430 | 0.030 |
| 1998 | 1 | C | 0 | 0.728 | 3.939 | 968 | 1020 | 0.102 |
| 1999 | 1 | CD | 0 | 0.730 | 1.553 | 576 | 616 | 0.471 |
| 2000 | 1 | C | 0 | 0.732 | 2.118 | 655 | 696 | 0.348 |
| 2001 | 1 | CE | 0 | 0.738 | 0.773 | 479 | 510 | 0.644 |
| 2002 | 1 | C | 0 | 0.744 | 2.712 | 1060 | 1100 | 0.075 |
| 2003 | 1 | CE | 0 | 0.750 | 0.837 | 387 | 409 | 0.806 |
| 2004 | 1 | C | 0 | 0.756 | 2.696 | 615 | 639 | 0.436 |
| 2005 | 1 | C | 0 | 0.761 | 0.846 | 522 | 540 | 0.590 |
| 2006 | 1 | CE | 0 | 0.767 | 2.040 | 493 | 507 | 0.649 |
| 2007 | 1 | C | 0 | 0.773 | 2.625 | 821 | 834 | 0.198 |
| 2008 | 1 | C | 0 | 0.779 | 3.564 | 832 | 841 | 0.194 |
| 2009 | 1 | C | 0 | 0.784 | 2.062 | 1020 | 1030 | 0.101 |