With all of the talk about renewable energy sources, many continue to argue for hydroelectricity as an important resource and maintain its long-term viability. Because many of the small, older dams have long-since paid for themselves, the argument is that they are a virtually free way to generate electricity locally. I recently had the opportunity to tour the Lake Zumbro dam owned by Rochester Public Utilities (RPU) and learned quite a few things I didn’t know and a few things I didn’t expect.
Built in 1920, the Zumbro dam provides Rochester with up to 2.6 megawatts of electricity daily, or approximately enough to power 370 homes annually. The original generators were replaced for the first and only time in 1984 and a small team of RPU workers keep the dam functioning, monitoring water levels and making adjustments as necessary to keep it performing optimally. But, much has changed since 1920 and as a result of computerized monitoring, it’s possible for anyone to now view daily lake levels at http://www.rpu.org/about-rpu/facilities/lake-zumbro-water-level.html.
But, the downside to damming the Zumbro river all those years ago is that over time, a significant amount of sediment has built up and whereas in the beginning it was a perfect recreational lake–surrounded by homes with docks and a destination for boaters and fishermen alike–now areas of sediment have become sandbars and are prohibiting access. The state has dedicated bonding dollars for $3.5 million of the $7 million overall project cost, RPU has set aside $1.17 million and Wabasha County, in which half of the lake resides, has approved $100,000. Now it’s up to Olmsted County to decide if they will make up the difference or if it will fall to residents on the lake to divide up that cost. The urgency is not so much because of the rate of sedimentation but because the state’s funds are only available through next year. If no agreement can be reached by then, the process will start all over.
Obviously, RPU has a stake in the project because steady flow is necessary for the dam to perform most efficiently. For residents on the lake, their home values and lifestyle are in jeopardy if the lake ceases to be good for recreation, but the counties feel that the cost is a lot to ask taxpayers, many of whom do not use the lake themselves. Advocacy groups like Lake Zumbro Forever are actively fundraising and advocating for the dredging and a recent discussion on the topic at the Rochester library, hosted by the Post Bulletin, drew a large crowd. So, while the Zumbro Dam is a virtually free generator of a significant electric supply, it is not without its issues and liabilities and in order to protect their investment, RPU is going to need the counties, residents and state to come together to preserve the lake’s integrity.
Stay tuned to the Post Bulletin for more information as decisions are made.