The National Weather Service is predicting a record amount of flooding this spring due to snow melt, but Dakota County is well positioned to pass the flood event safely. The Byllesby Dam has the capacity to accommodate a significant amount of water safely passing over the dam without ever being at risk structurally.
Lake Byllesby has the storage potential for additional rain and snow melt draining into it from the Cannon River. The lake level is currently lowered 3 feet to an elevation of 853.7 feet due to our annual drawdown requirements during the winter period.
Dakota County plans to keep the water levels below the normal summer elevation during the spring floods, which is 856.7 feet above sea level, to accommodate abrupt changes in water levels downstream in the Cannon River in Cannon Falls. As a result, there is currently no need to sandbag around Lake Byllesby.
Historically, the record event at the Byllesby Dam was in 1965 when 36,500 cubic feet per second (cfs) was discharged. The current capacity at the Dam can accommodate 80,800 cfs, over double the flood on record. Discharge levels at the dam are 3,000 cfs and continue to rise. There is currently no indication of how much flow the dam could receive.
Dakota County continues to work closely with the City of Cannon Falls, Dakota County Emergency Preparedness and Goodhue County Emergency Management to track weather conditions. Anyone adjacent to the Cannon River downstream of the dam should consult with the City of Cannon Falls and Goodhue County to prepare for any potential flooding concerns.
For safety purposes, we encourage people to stay off the ice due to cracking and other changes in the reservoir.
For more information regarding flowrates and water levels at the dam, contact the Byllesby Dam Hotline at 651-438-4626 or go to the Lake Byllesby Dam page.