Observed and urbanization-adjusted annual maximum peak discharge and associated urban fraction and precipitation values at USGS streamgage:
05549700 MUTTON CREEK AT ISLAND LAKE, 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
1960 1 7 0 0.021 0.513 378 513 0.008
1962 1 -- 0 0.023 0.262 172 251 0.069
1963 1 -- 0 0.025 1.267 20 43 0.952
1964 1 -- 0 0.026 0.914 24 50 0.933
1965 1 -- 0 0.027 0.063 114 171 0.221
1966 1 -- 0 0.028 0.481 111 167 0.238
1967 1 -- 0 0.029 1.285 45 79 0.785
1968 1 -- 0 0.031 1.237 47 82 0.769
1969 1 -- 0 0.032 1.337 98 150 0.317
1970 1 -- 0 0.033 1.521 37 68 0.852
1971 1 -- 0 0.035 0.423 263 361 0.019
1972 1 -- 0 0.037 0.999 75 120 0.499
1973 1 -- 0 0.039 1.462 82 129 0.437
1974 1 -- 0 0.041 1.115 57 94 0.682
1975 1 -- 0 0.043 0.814 33 62 0.886
1976 1 -- 0 0.045 1.582 220 307 0.036