Observed and urbanization-adjusted annual maximum peak discharge and associated urban fraction and precipitation values at USGS streamgage:
05438250 COON CREEK AT RILEY, 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
1962 1 -- 0 0.019 0.361 1150 1340 0.499
1963 1 2E 0 0.020 0.247 220 287 0.975
1964 1 E 0 0.020 0.817 220 287 0.975
1965 1 -- 0 0.020 0.105 985 1150 0.613
1966 1 -- 0 0.021 0.642 1390 1600 0.371
1967 1 -- 0 0.021 1.891 1250 1450 0.441
1968 1 E 0 0.021 1.812 1220 1410 0.459
1969 1 -- 0 0.021 0.127 1670 1900 0.258
1970 1 -- 0 0.022 1.969 1940 2190 0.178
1971 1 -- 0 0.023 0.381 1670 1900 0.259
1972 1 -- 0 0.024 1.053 1770 2000 0.224
1973 1 -- 0 0.026 1.505 3020 3370 0.050
1974 1 -- 0 0.027 0.594 1150 1330 0.506
1975 1 -- 0 0.029 0.794 797 936 0.732
1976 1 -- 0 0.030 1.277 1480 1680 0.338
1977 1 -- 0 0.031 1.255 134 177 1.000
1978 1 -- 0 0.033 2.258 5090 5560 0.012
1979 1 -- 0 0.034 0.289 2140 2390 0.143
1980 1 -- 0 0.036 0.388 811 943 0.728
1981 1 E 0 0.036 1.886 479 576 0.899
1982 1 -- 0 0.037 0.340 1360 1540 0.395
1983 1 -- 0 0.038 1.867 2520 2800 0.086
1984 1 -- 0 0.039 0.766 738 859 0.772
1985 1 -- 0 0.040 0.532 2020 2250 0.168
1986 1 -- 0 0.041 1.088 1490 1680 0.340
1987 1 -- 0 0.042 2.260 2110 2340 0.151
1988 1 -- 0 0.043 1.005 779 900 0.753
1989 1 -- 0 0.044 1.183 850 976 0.709
1990 1 -- 0 0.045 1.591 1130 1280 0.534
1991 1 -- 0 0.047 1.233 970 1100 0.639