Sliding gate would add $90,000 to estimate
By Bert Lehman
The engineering firm hired by the city of Clintonville to create a plan to repair the Pigeon River Dam presented an estimate of $165,000.
Peter Haug, project manager at Ayres Associates, informed the Street Committee, at its July 5 meeting, about the repairs that are needed for the Pigeon River dam.
Haug said he inspected the dam two years ago and found deficiencies.
The committee was presented with what Haug called a “10 percent concept plan.” He said the plan is a starting point for discussion but nothing has been finalized.
One of the problems with the dam is the concrete has some issues, Haug said. When the dam was redone in the mid-1990s, Haug said gunite was used. Gunite was sprayed out of a hose over the top of the existing dam structure.
“The problem with gunite is it looks great for about a year and then the Wisconsin freeze, thaw weather starts to take its toll,” Haug said. “The biggest problem with gunite is you can not ever inspect what’s underneath it again. It’s like a hard shell on an ice cream cone. You don’t know how bad it has dissolved or how bad the material is underneath it.”
The gates on the dam also need repairs. There is a leak in gate three which Haug said was minor, and the entire seal probably won’t need to be replaced. The bigger problem is the fact the gates are susceptible to expanding and contracting. This leads to leakage problems.
A major problem is the abutment wall on the side of the dam is shifting and pulling the alleyway behind it down with it, Haug said.
Two solutions were presented to correct the wall issue — a gravity wall option and an anchor wall option. The anchor wall option could save the city money, but Haug said since the city doesn’t own the adjoining property that option isn’t feasible.
“I think it raises a lot of questions about using somebody else’s property to strengthen those anchors,” Haug said.
The gravity wall costs more than an anchor wall but it won’t intrude on the adjoining property, Haug said. This would entail adding a new wall over the existing wall. This will narrow the river in that area.
Another problem is the galvanized walkway is pulling away from one of the abutments.
Haug also informed the committee about different gate options. Clintonville Public Works Director Toby Kersten said there is a lot of leakage in the winter, as well as a lot of ice build-up. The ice build-up is a problem if there is a quick thaw in the spring. Haug said a slide gate would solve that problem, but it costs about $90,000.
Haug told the committee that if the city received a grant from the DNR for the repairs, the DNR match is 50 percent of the first $400,000 of the dam repair project.
“I don’t foresee that in the budget you have in front of you, even if you went with a new gate, I don’t think you would be past that,” Haug said.
To bring in a contractor onsite to perform miscellaneous work including replacing the seals, it will cost $60,000, Haug said.
“A large portion of that is the opportunity cost, getting the contractor to the site, setting up, bringing a crane out here,” Haug said.
The seals cost only $13,000, he said.
“The commitment here, you bring a contractor on site you might as well get the work done because every time you bring a contractor onsite you lose 50 grand,” Haug said.
The concrete spall repairs will cost $20,000-$30,000. A new containing wall will cost $60,000. The walkway repairs will cost $2,500. These costs assume a contractor is already onsite.
The total estimate was $165,000.
If the city wanted to replace one of the dam gates with a sliding gate, that cost would be around $90,000, upping the total cost to $255,000. That cost also assumes a contractor is already onsite.
Haug cautioned that the estimate could increase depending on the condition of the concrete in the dam. That won’t be known until the contractor starts removing the gunite. He cited an example of a dam repair in Altoona that was similar to Clintonville’s current situation. He said once work began the repair costs almost doubled because of the condition of the concrete in the dam.
“You can tell them to stop, but do you really want them to? You want them to fix that,” Haug said.
He added that 30 percent of the cost of a project like this is contractor change orders.
The next DNR grant application period is in the fall of 2017.
“We want to have the final design done at least 90 days before the grant [period] starts, so you probably want the final design done by next June or July,” Haug said.
He added that it will take about six weeks to complete the final design for this project.
“I think your project is unique because most people who apply for a grant not knowing what they need,” Haug said. “… Here we have the luxury of not applying until October 2017 so you can take the time you want to vet these things and develop budgets for them.”
Clintonville City Administrator Chuck Kell said since the city wants to apply for the DNR grant, there isn’t a rush to move forward with this project. He also stressed that the city needs to keep the project on the “front burner” because the city is in its current situation because the dam repair issues were not acted on in the past.
Kell added that the city could also budget this project over a two year period.