Observed and urbanization-adjusted annual maximum peak discharge and associated urban fraction and precipitation values at USGS streamgage:
05551900 EAST BRANCH BIG ROCK CREEK NEAR BIG ROCK, 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
1965 1 -- 0 0.004 0.079 680 701 0.507
1966 1 -- 0 0.004 0.481 795 818 0.397
1967 1 -- 0 0.004 1.113 668 688 0.520
1968 1 2 0 0.004 1.332 243 254 0.921
1969 1 -- 0 0.004 0.110 542 559 0.657
1970 1 -- 0 0.005 1.458 550 567 0.649
1971 1 -- 0 0.006 0.378 498 514 0.704
1972 1 -- 0 0.007 1.080 1410 1440 0.100
1973 1 -- 0 0.008 1.480 744 763 0.446
1974 1 -- 0 0.009 1.329 1580 1610 0.072
1975 1 -- 0 0.010 0.844 398 409 0.802
1976 1 -- 0 0.011 1.095 458 470 0.749
1977 1 -- 0 0.012 0.141 382 392 0.818
1978 1 -- 0 0.013 1.389 713 727 0.480
1979 1 -- 0 0.014 0.353 889 904 0.335