Flood in McHenry County, Illinois

Heavy rain fell across McHenry County and southeast Wisconsin between July 11th and July 13th which lead to major flooding along the Fox River. The river gage at the McHenry Lock & Dam crested at 7.60 feet on July 22nd, the second highest crest on record. Flood stage at the McHenry Lock & Dam is 4 feet. The river gage at the Algonquin Tailwater measured a record crest of 13.15 feet on July 24th. Flood stage at the Algonquin Tailwater is 9.5 feet. There were 557 homes affected with some amount of water from the river flooding.

Thunderstorms developed during the late evening of July 11th across far northeast Illinois and continued into the morning of July 12th producing torrential rainfall which continued over the same areas for hours producing flash flooding and major river flooding.