Rochester Public Utilities | Blog

Archive for December, 2016

RPU warns of unstable ice on Lake Zumbro

Monday, December 19th, 2016

Rochester Public Utilities (RPU) warns of the danger of unstable ice on Lake Zumbro.

RPU draws down Lake Zumbro to a level of approximately 913.0 for the winter season, to prevent damage to retaining walls and shorelines on the lake, as well as for deicing along the dam. Due to a number of factors including increased flow into Lake Zumbro and an emergency outage on a turbine at the RPU Hydroelectric Plant, RPU has not been able to reach and maintain the winter pool level.

RPU will continue to draw the lake level down to the winter pool level even as the ice sets in. The ice will continue to be dangerous because of the drawdown and the lake not being able to settle and freeze. Visible ice on the lake, especially close to shore, may be very unstable because it hasn’t had time to set at the winter pool level.

According to the Minnesota Department of Natural Resources (DNR), ice is not safe to walk on until it is 4 inches in thickness.

Visit the Minnesota DNR for additional ice safety information and view the link to the ice safety level on their website

Real-time lake level information, along with Lake Zumbro hydro updates are available on the RPU web site ( For additional information regarding the winter pool drawdown contact Todd Osweiler at 507.280.1589.

Tips for lake ice safety:

Be extremely careful during winter activities that involve Lake Zumbro such as ice fishing, snowmobiling or just walking out on the frozen lake.
Watch the weather and river flow conditions.
Ice thickness and condition can vary greatly. Be very cautious.
Look out for ice heaves and exposed logs and snags.
Be cautious in the vicinity of the dam. De-icing equipment has been installed along the upstream face of the dam resulting in open water and/or thin ice.
Do not proceed past the warning signs and buoys.

About Rochester Public Utilities

As the municipal utility of Rochester, Minn., for more than 110 years, RPU provides high-quality and reliable electricity to over 50,000 customers. Water customers number more than 37,000. RPU continually investigates innovative technologies to help customers realize the best value from the services they receive. Current initiatives include fuel cell research, wind power, and photovoltaic offerings.