This may not be boating season, but the Rock County Sheriff’s Office has declared a “Slow-no-Wake” restriction for the entire Rock River. Officials point to the U.S. Geological Survey Gauges measuring the water level at slightly more than 9.5 feet at Lake Koshkonong, and more than 9 feet at Afton. Slow-no-Wake is issued when water levels rise above 8 feet at Lake Koshkonong and 6.5 feet at Afton.