The third biggest flood , cresting at 29 @.@ 8 feet ( 9 @.@ 1 m ) in Lock Haven , occurred on June 1 , 1889 , and coincided with the Johnstown Flood . The flood demolished Lock Haven 's log boom , and millions of feet of stored timber was swept away . The flood damaged the canals , which was subsequently abandoned , and destroyed the last of the canal boats based in the city .