Observed and urbanization-adjusted annual maximum peak discharge and associated urban fraction and precipitation values at USGS streamgage:
05536275 THORN CREEK AT THORNTON, 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
1947 1 -- 976 0.185 2.851 4200 5680 0.030
1948 1 -- 976 0.192 2.072 4040 5460 0.035
1949 1 -- 976 0.200 0.815 1320 2040 0.578
1950 1 -- 976 0.207 1.518 2010 2880 0.276
1951 1 -- 976 0.220 2.365 2720 3740 0.129
1952 1 -- 976 0.233 1.048 1570 2290 0.472
1953 1 -- 976 0.246 1.743 2280 3100 0.220
1954 1 -- 976 0.260 1.468 1890 2620 0.356
1955 1 -- 976 0.273 3.955 3370 4370 0.073
1956 1 -- 976 0.286 1.325 2280 3000 0.244
1957 1 -- 976 0.299 2.412 4700 5790 0.028
1958 1 -- 976 0.312 1.330 1560 2110 0.548
1959 1 -- 976 0.325 1.408 1780 2340 0.455
1960 1 D 976 0.339 1.356 1220 1660 0.735
1961 1 -- 976 0.347 1.926 2420 3000 0.244
1962 1 -- 976 0.356 0.230 1100 1490 0.796
1963 1 -- 976 0.365 1.699 975 1330 0.849
1964 1 -- 976 0.373 1.116 621 908 0.950
1965 1 -- 976 0.382 1.054 1290 1660 0.735
1966 1 -- 976 0.391 2.035 3240 3810 0.121
1967 1 -- 976 0.399 1.273 1690 2070 0.564
1968 1 -- 976 0.408 2.132 3420 3950 0.104
1969 1 -- 1515 0.417 0.680 1090 1370 0.835
1970 1 -- 1515 0.425 1.331 1830 2170 0.523
1971 1 -- 1515 0.432 1.100 1250 1520 0.784
1972 1 -- 1515 0.438 1.256 1410 1680 0.724
1973 1 -- 1515 0.445 1.031 3060 3430 0.168
1974 1 -- 1515 0.451 1.713 2970 3310 0.184
1975 1 -- 1515 0.457 1.453 1630 1880 0.642
1976 1 -- 1568 0.464 1.702 1940 2200 0.510
1977 1 -- 1568 0.470 1.277 1580 1800 0.676
1978 1 -- 1568 0.476 1.242 2020 2250 0.489
1979 1 -- 1568 0.483 0.641 2680 2920 0.263
1980 1 -- 1568 0.489 0.971 1440 1620 0.751
1981 1 -- 1568 0.491 2.182 4140 4430 0.070
1982 1 -- 1568 0.493 2.538 2370 2580 0.370
1983 1 -- 1568 0.494 2.458 3370 3610 0.146
1984 1 -- 1568 0.496 1.090 2060 2250 0.491
1985 1 -- 1568 0.497 1.008 2110 2300 0.472
1986 1 -- 1568 0.499 1.368 1630 1790 0.680
1987 1 -- 1568 0.501 1.982 1350 1500 0.792
1988 0 -- 2657 0.502 0.715 964 1120 0.912
1989 2 -- 2657 0.504 1.903 3000 3290 0.188
1990 2 -- 2657 0.506 1.507 1620 1820 0.667
1991 2 -- 2657 0.508 2.868 4210 4570 0.063
1992 2 C 2657 0.510 2.114 1070 1230 0.881
1993 2 C 2657 0.512 2.094 2610 2860 0.280
1994 2 C 2657 0.514 1.403 1640 1830 0.665
1995 2 C 2657 0.516 1.114 1400 1570 0.767
1996 2 C 2657 0.518 4.279 4470 4810 0.052
1997 2 C 2657 0.520 2.160 3370 3640 0.142
1998 2 C 2657 0.522 1.496 2360 2570 0.373
1999 2 C 2657 0.524 0.787 2230 2430 0.423
2000 2 C 2657 0.526 1.155 1390 1540 0.777
2001 2 C 2657 0.533 0.636 1900 2060 0.568
2002 2 C 2657 0.541 1.461 2920 3100 0.222
2003 2 C 2657 0.549 1.860 2730 2880 0.274
2004 2 C 2657 0.557 2.321 2340 2460 0.413
2005 2 C 2657 0.564 1.123 3400 3520 0.157
2006 2 C 2919 0.572 2.603 5540 5680 0.030
2007 0 C 2919 0.580 1.837 2820 -- --
2008 0 C 2919 0.588 4.412 5860 -- --
2009 0 C 2919 0.595 1.089 3490 -- --