Observed and urbanization-adjusted annual maximum peak discharge and associated urban fraction and precipitation values at USGS streamgage:
05538440 SPRING CREEK NEAR ORLAND PARK, 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
1955 1 7 0 0.192 3.214 112 180 0.018
1961 1 -- 0 0.296 1.419 66 106 0.125
1962 1 2 0 0.305 0.268 32 58 0.610
1963 1 2 0 0.314 1.497 30 55 0.659
1964 1 -- 0 0.323 0.926 23 45 0.807
1965 1 -- 0 0.332 0.871 23 45 0.812
1966 1 -- 0 0.341 1.399 78 119 0.080
1967 1 -- 0 0.350 1.141 56 87 0.225
1968 1 2 0 0.359 1.468 37 62 0.545
1969 1 -- 0 0.368 0.145 39 65 0.511
1970 1 -- 0 0.377 1.085 49 77 0.338
1971 1 2 0 0.390 0.931 15 32 0.944
1972 1 -- 0 0.404 1.232 37 60 0.588
1973 1 -- 0 0.418 0.839 62 90 0.202
1974 1 -- 0 0.432 1.210 50 75 0.367
1975 1 -- 0 0.446 1.006 46 69 0.448
1976 1 -- 0 0.459 0.904 34 53 0.697
1977 1 -- 0 0.473 1.431 38 57 0.628