In 1936, all the flood gates were opened for the first time. During Hurricane Agnes, in 1972, all 53 flood gates were opened, for only the second time, and explosives planted to blow a section of the weir, as the waters rose during the early morning hours of June 24 within of topping the dam (a record crest of , above normal level for the entire long Conowingo Reservoir.) Paul English, dam superintendent, released a bulletin at 10:30 p.m. on June 23 saying that the water levels were reaching a point at which the stability of the dam "cannot be controlled. When it reaches ...it will be in the hazy area...It is not known...whether a structure of the dam may give and...people downstream should be advised." At this time, the flow sensor in the dam recorded its record discharge of , and the stream height gauge, at the dam's downstream side, registered a record . On January 20, 1996, the gauge recorded its second-highest recorded crest of . A severe ice jam also developed behind the dam on this date. The record minimum recorded discharge was on March 2, 1969, when the flow sensor registered .