The Fox Waterway Agency has issued a no wake and debris advisory alert for the Fox River.
Zone A of the river, which extends from the McHenry dam to the Algonquin dam, is a no wake zone with a debris advisory, the agency announced Friday morning.
The upper river and lake remain open for full boating, but a debris advisory is in place, according to the agency.
The National Weather Service has also issued a flash flood watch expected to remain in place through Saturday morning in McHenry County. Heavy rain and thunderstorms are expected to produce up to 2 inches of rain per hour.
The Fox River at the McHenry dam is nearing its 4-foot flood stage, according to the National Weather Service.
At 9:15 a.m. Friday, the river was at 3.68 feet.