RAPIDAN — The beleaguered Rapidan Dam continues to weigh on the minds of Blue Earth County commissioners.
At their first meeting of the year, which included new board member Kevin Paap, whose district the dam is in, approved two more engineering studies of the 111-year old dam as they prepare to decide whether to remove the structure or continue repairing it.
The board unanimously approved the two studies to be done by Barr Engineering, which has done several past studies of the dam.
Public Works Director Ryan Thilges said one study, costing a maximum of $69,700, will study the long-term feasibility and costs of repairing and maintaining the dam.
A second study, costing up to $117,800, will look at the costs of removing the dam as well as the potential to develop a larger regional park near the dam and possibly creating a whitewater rapids if the dam is removed.
Commissioners, who’ve heard complaints of the money that’s been poured into studies and repairs over the years, said they are destined to make a big decision with a massive price tag attached, no matter which route they choose.
Vance Stuehrenberg said the dam has been the focus of many studies and discussions with multiple agencies.
“It would be great to have a final solution with this. This is one of those things — damned if you do, damned if you don’t with a dam.”
Paap said that because cost estimates and environmental requirements continue to change, the board needs the best information as a decision is made.
“To some it might seem, why do two studies? But if we’re going to continue to have those conversations and decisions, doing nothing is not an option. The only way we can work toward those decisions is to have the most current facts.”
Kip Bruender said that while a lot of money has been put into the dam, “We have to keep it safe.”
Big dollar decisions
Since 2008, $3.82 million has been spent on the dam on the Blue Earth River southwest of Mankato, according to Thilges. The repairs were needed because of the age of the dam and because it’s been hammered by flood waters.
The latest assault on the dam came last winter when an ice dam built up downriver, which caused water to back up to the dam and flood the electric powerhouse with 15 feet of water, ruining electrical generation equipment. The plant hasn’t produced any electricity since.
The company that ran the power plant ended its contract with the county after the plant was ruined. The revenue the county got from the power plant wasn’t significant but it at least provided some offset to ongoing repair costs for the dam.
The county will need to decide whether to repair the power plant to working order and make necessary repairs to the dam; only do repairs needed to keep the dam safe; or remove the dam.
Two decades ago the estimated cost of removing the dam was pegged at $20 million. Thilges estimates the removal cost would now be about $50 million.
If the county chooses to repair the power plant, the last study said it would cost an estimated $2.3 million. That would be on top of other necessary structural repairs that had previously been identified. Those include an estimated $2.7 million apron repair and $450,000 for repairs to damaged tainter gates.
Removal of the dam has been looked at before, but the price tag is immense because polluted silt that fills a large area behind the dam would have to be taken out and disposed of before the dam could be removed.
Thilges has been looking at multiple federal and state agencies for potential funding, whatever track commissioners finally choose.
It’s unlikely a final decision will be reached this year. The latest two studies are expected to take six to 12 months.