Rochester Public Utilities | Blog

Archive for October, 2023

2023 Lake Zumbro Dam Fall Drawdown

Friday, October 6th, 2023

ROCHESTER, MN—The fall drawdown of Lake Zumbro is scheduled to begin on October 29th. The drawdown is necessary for planned maintenance at the hydroelectric facility and shoreline restoration work.  The public should be aware that the drawdown planned for this fall will be substantially greater than normal.  A typical fall drawdown is less than two feet; whereas this year a four foot drawdown will be attempted.  These plans are subject to change depending on rainfall and resulting runoff.  RPU’s drawdown plan is as follows:

  • Sunday, October 29th start the 4 foot drawdown.
    • RPU will plan to draw the lake level down 0.5 feet per day while maintaining a minimum flow of 70 cfs.
  • Monday, November 6th the lake level will be held at 910.5 (~4.0 feet below the spillway) for 2 weeks.
  • Monday, November 20th start to slowly refill the lake level until it reaches the winter pool elevation of 913.0
    • RPU will plan to refill the lake level while maintaining a minimum flow of 70 cfs.

The drawdown plan is subject to change depending on weather conditions.

During the months of December through March, Rochester Public Utilities (RPU) will attempt to maintain the lake level at the winter pool of 913.0 MSL.

Real-time lake level information, along with Lake Zumbro hydro updates are available on the RPU web site ( For additional information regarding the Zumbro Hydroelectric Facility please contact Tony Benson at (507) 280-1534.

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 56,000 customers.  Water customers number more than 40,000.  RPU continually investigates innovative technologies to help customers realize the best value from the services they receive.  Current initiatives include photovoltaic offerings, wind energy, energy and water efficient equipment, and electric vehicle charging.