ERCA Maximum Observed Flooding Flood levels observed due to ice jamming in Feb 1985. They were staked and serveyed by ERCA staff where the observed flood levels surpassed the 1:100 yr flood line. In some cases, these levels are above the Hurricane Hazel flood levels. Source: Deliniation of areas with maximum observed flooding for specific events. Does not include the Harrow flood of 1989. Data created by Geordon Harvey (ERCA) ~ 2000. Licensed to faculty, staff and students at the University of Windsor only. All others please contact the Essex Region Conservation Authority.