Lake Zumbro drawdown will be greater than normal
The annual drawdown of Lake Zumbro planned for this fall will be substantially greater than normal.
A typical fall drawdown is less than two feet. This year, Rochester Public Utilities is planning a six-foot drawdown.
The additional drawdown is needed to complete routine maintenance on the minimum flow gate at the dam, said RPU spokesman Tony Benson. Homeowners can also do shoreline restoration work because of the additional access during the drawdown, he said.
The drawdown is scheduled to begin on Oct. 17. This will be a gradual drawdown from summer pool elevation of 919.7 and continuing releasing water until a target elevation of 913.5 is achieved. Depending on the weather, the target elevation could be reached by Oct. 30.
The plan is to maintain the lake level at or about 913.5 from Oct. 30 through Nov. 6. The lake refill should begin on Nov. 7. The level would be slowly raised back up to the normal winter pool level at a rate no more than half-a-foot per day. A minimum of 10 days will be required to raise the lake level to normal winter pool level of 918.5 to minimize the impact on downstream resources.
From November through March, RPU will attempt to maintain the lake level within the winter pool range.
Real-time lake level information, along with Lake Zumbro hydro updates, are available on the RPU website.
