On April 9, 1973 a Nor'easter storm event on Green Bay caused flooding 4 feet deep in downtown Green Bay, Wisconsin. Flood waters reached the elevation of the 500-year flood as strong winds blowing the length of the bay produced storm surge on already high lake levels. Erosion damage occurred on the open coast with property damage due to flooding in the City of Green Bay alone being estimated at several million dollars (NOAA, 1973; FEMA, 2011).
The 1973 storm occurred during a period of higher lake levels, but even during low lake level periods, coastal storms can produce high waves and storm surge. For example, in December, 1990 a winter storm produced the largest recorded water level in the lake, at the Green Bay gage, located at the southern tip of Green Bay (Jensen et al., 2012). Then again on December 9, 2009, the same gage recorded a peak storm surge ranked as the second highest for the gage. (Melby et al., 2012)
These extreme waves and storm surge can affect property owners on the coast and further into the coastal watershed due to the combined impact of storm surge and riverine flooding.
The following photos help visualize the extent of flooding during this storm: