Observed and urbanization-adjusted annual maximum peak discharge and associated urban fraction and precipitation values at USGS streamgage:
05540275 SPRING BROOK AT 87TH STREET NEAR NAPERVILLE, IL

Observed annual peak-flood magnitudes were adjusted to 2010 land-use conditions on the basis of panel data regression model with fixed effect analysis. The symbols presented in the figure are: "observed annual peaks", "adjusted annual peaks", and "fraction of urbanization in the watershed"

Legend for Graph

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
1988 1 -- 79 0.481 1.108 78 115 0.918
1989 1 -- 79 0.507 1.579 80 113 0.922
1990 1 D 79 0.534 1.808 694 793 0.010
1991 1 -- 79 0.545 1.478 267 314 0.195
1992 1 E 79 0.557 1.776 134 165 0.744
1993 1 -- 79 0.568 1.721 153 184 0.663
1994 1 E 79 0.579 0.712 147 175 0.704
1995 1 -- 79 0.590 1.270 107 130 0.876
1996 1 -- 79 0.602 3.675 1750 1890 0.000
1997 1 -- 144 0.613 2.517 465 507 0.039
1998 1 -- 144 0.624 1.251 391 425 0.071
1999 1 -- 144 0.635 0.599 218 239 0.429
2000 1 C 144 0.647 1.486 178 194 0.616
2001 1 C 144 0.654 0.694 208 224 0.489
2002 1 C 144 0.661 2.204 538 563 0.027
2003 1 C 144 0.668 0.902 129 139 0.843
2004 1 C 144 0.675 1.741 164 173 0.712
2005 1 C 144 0.683 1.191 195 203 0.574
2006 1 CE 144 0.690 1.625 66 70 0.981
2007 1 C 144 0.697 2.328 188 193 0.620
2008 1 C 144 0.704 2.736 422 427 0.069
2009 1 C 144 0.711 1.006 473 476 0.047