Dakota County will refill the Lake Byllesby reservoir to its summer elevation beginning Sunday, May 15.
In the fall, the reservoir level is lowered 3 feet to 853.7 feet and remains there until May 15 when refilling to the summer elevation of 856.7 feet is permitted to start. The Minnesota Department of Natural Resources sets these seasonal lake levels to make it easier for farmers to get into their lower-lying fields in the spring and to offer residents water recreation opportunities in the summer. Refilling is expected to be complete by Memorial Day weekend.
Refilling the reservoir is done by raising 41 trip gates located at the top of Lake Byllesby Dam. Up to 20 percent of the water flowing from the Cannon River into the reservoir is captured to fill the pool. The remaining 80 percent of inflow is released downstream to ensure continued flow in the river.
To ensure adequate flow downstream, the reservoir cannot be refilled if the flow of the river, as measured in Welch, drops below 50 percent of the normal water-flow levels.
Access weather data at the Byllesby Dam and lake level information generated from river gages at www.byllesbydam.org. For information about the refill process, call Dakota County Environmental Resources at 952-891-7000.