Observed and urbanization-adjusted annual maximum peak discharge and associated urban fraction and precipitation values at USGS streamgage:
05534600 NORTH BRANCH CHICAGO RIVER AT NORTHFIELD, 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 -- 0 0.317 0.441 358 601 0.370
1961 1 -- 0 0.327 1.257 277 482 0.581
1962 1 -- 0 0.338 0.230 307 520 0.507
1963 1 -- 0 0.349 1.280 204 375 0.783
1964 1 -- 0 0.359 0.802 214 384 0.767
1965 1 -- 0 0.370 0.525 273 457 0.627
1966 1 -- 0 0.381 0.500 361 573 0.416
1967 1 -- 0 0.391 1.407 470 699 0.228
1968 1 -- 0 0.402 0.734 213 367 0.796
1969 1 -- 0 0.413 2.037 424 633 0.315
1970 1 -- 0 0.423 1.799 327 505 0.535
1971 1 -- 0 0.432 0.347 430 631 0.319
1972 1 -- 0 0.440 2.319 424 620 0.338
1973 0 -- 600 0.448 1.232 473 668 0.264
1974 2 -- 600 0.457 1.254 384 558 0.443
1975 2 -- 600 0.465 1.024 399 572 0.419
1976 2 -- 600 0.474 1.299 481 661 0.274
1978 2 -- 600 0.491 1.581 307 443 0.654
1979 2 -- 600 0.499 0.949 471 636 0.309
1980 2 -- 600 0.508 0.600 232 348 0.827