Observed and urbanization-adjusted annual maximum peak discharge and associated urban fraction and precipitation values at USGS streamgage:
05536255 BUTTERFIELD CREEK AT FLOSSMOOR, 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
1948 1 -- 0 0.124 1.870 970 1590 0.057
1949 1 -- 0 0.130 0.749 465 843 0.395
1950 1 -- 0 0.136 1.194 555 961 0.283
1951 1 -- 0 0.156 2.065 525 908 0.332
1952 1 -- 0 0.175 0.957 339 621 0.658
1953 1 -- 0 0.195 2.051 810 1280 0.121
1954 1 -- 0 0.215 1.420 450 758 0.489
1955 1 -- 0 0.235 4.253 1380 2000 0.025
1956 1 -- 0 0.255 1.273 510 814 0.428
1957 1 -- 0 0.275 2.396 2000 2750 0.010
1958 1 -- 0 0.295 1.288 311 514 0.784
1959 1 E 0 0.315 1.481 375 587 0.702
1960 1 -- 0 0.335 1.228 318 502 0.798
1961 1 -- 0 0.348 2.123 935 1280 0.119
1962 1 -- 0 0.361 0.231 297 459 0.840
1963 1 E 0 0.375 1.801 187 311 0.949
1964 1 E 0 0.388 1.033 251 388 0.905
1965 1 -- 0 0.401 1.125 405 572 0.720
1966 1 -- 0 0.415 2.325 888 1150 0.169
1967 1 -- 0 0.428 1.329 424 578 0.713
1968 1 -- 0 0.441 2.598 1680 2070 0.022
1969 0 -- 539 0.455 0.591 432 553 0.743
1970 2 -- 539 0.468 1.308 666 787 0.458
1971 2 -- 539 0.478 1.174 376 459 0.840
1972 2 -- 539 0.488 1.245 399 479 0.822
1973 2 2 539 0.498 1.093 820 927 0.310
1974 2 -- 539 0.508 2.140 1480 1630 0.051
1975 2 -- 539 0.518 1.519 548 619 0.661
1976 2 D 592 0.528 1.505 586 653 0.620
1977 2 -- 592 0.538 1.396 964 1040 0.222
1978 2 -- 592 0.548 1.279 932 999 0.249
1979 2 -- 592 0.557 0.566 730 782 0.464
1980 2 -- 592 0.567 1.340 448 481 0.819
1981 2 -- 592 0.570 2.350 1980 2060 0.023
1982 2 -- 592 0.572 3.169 2160 2240 0.018
1983 2 -- 592 0.575 2.697 1700 1760 0.040
1984 2 -- 592 0.577 1.243 1020 1060 0.209
1985 2 -- 592 0.579 1.070 816 852 0.388
1986 2 -- 592 0.582 1.494 713 744 0.508
1987 2 -- 592 0.584 1.617 711 740 0.513
1988 2 -- 592 0.586 0.423 512 535 0.763
1989 2 -- 592 0.589 2.117 870 898 0.339
1990 2 -- 592 0.591 2.121 829 854 0.385
1991 2 -- 592 0.593 3.365 2090 2130 0.020
1992 2 C 592 0.595 2.275 465 481 0.819
1993 2 C 592 0.596 2.504 1070 1090 0.193
1994 2 CE 592 0.598 1.780 909 929 0.307
1995 2 C 592 0.600 1.136 575 589 0.702
1996 2 C 592 0.601 5.241 2220 2250 0.018
1997 2 CE 592 0.603 2.255 1070 1090 0.196
1998 2 C 592 0.605 1.535 707 719 0.538
1999 2 C 592 0.606 1.272 710 720 0.536
2000 2 C 592 0.608 1.261 497 505 0.795
2001 2 C 592 0.609 0.535 544 551 0.745
2002 2 C 592 0.610 1.432 949 957 0.282
2003 2 C 592 0.611 2.399 634 640 0.635
2004 2 C 592 0.613 3.408 931 937 0.299
2005 2 CE 592 0.614 1.020 774 779 0.468
2006 2 C 592 0.615 3.021 2640 2650 0.012
2007 2 C 592 0.616 2.006 840 843 0.398
2008 2 C 592 0.617 4.801 2020 2020 0.024
2009 2 C 592 0.618 1.198 788 789 0.456