A long-troubled rock dam regulating flow between Big Pine Lake and the Pine River in Crosslake will be removed.
The Crow Wing County Board Tuesday heard the future plans for the dam, the subject of numerous repair projects in the 47 years since its construction. County Engineer Tim Bray told the board the most recent maintenance completed was already breached by water flowing from the lake to the river. Erosion along the river bank over time led to the loss of trees.
"Big Pine Lake is flowing free around the east side of that repair," Bray said. "What we're here to talk about is a permanent solution."
That solution is to remove the dam and replace it with a series of five rock weirs, coaxing the water to flow on a gradual downward slope toward the narrowing banks of the tributary. The weir arrangement is called an arch riffle structure and uses various sizes of boulders, fabric and sediment to minimize water seepage. An earthen dike and stabilization of the shore will strengthen the river banks to increased flows from rain events and changes at the Army Corps of Engineers dam upstream.
The structure is designed with fish in mind, explained Bill Westerberg, an engineer with the North Central Minnesota Joint Powers Board who is working with the Crow Wing Soil and Water Conservation District on the project.
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"It allows fish passage to go up and down, a lot easier than it was before," Westerberg said. "There will be a pool between each of them (the weirs), so the fish can rest before they go to the next one."
Westerberg said groups in the Red River Valley used similar structures in several locations-17 to be exact-to improve the flow and fish accessibility in tributaries.
The timing of the reconstruction, planned for January or February 2018, is concerning for property owners on Big Pine Lake, Bray said. Westerberg said this time of year was selected because it is a period of low flow, but Bray asked him to explore the possibility of completing the project sooner.
"January is a whole year away, and that's a whole summer without water," Bray said. "And I know they're concerned about that."
Bill Korchik, vice president of the Big Pine Lake Association, said there is some urgency in addressing the water levels of the lake. He said the water levels are tied to whatever is flowing from the Corps of Engineer dam, and are noticeably impacted by the breach on the rock dam.
"It's obvious that the lake, even with the ice on it, that the lake is down," Korchik said. "I almost wonder if you ice fish if you wouldn't hit air instead of water. And actually, that happened in the past, when the dam blew out. ... Spring is coming and much of the lake may not well be usable."
Korchik said if some of the construction could begin sooner, it could prevent some of the water loss in the lake-although it could also amount to throwing money away for a stop gap until the replacement could begin.
"I would look to the engineers, to the experts here, to see if there's anything they can possibly do to phase the project such as it would help us out," Korchik said, before adding, "A miracle?"
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The board and others laughed in response to Korchik.
"I'm trying to understand whether we should pray for rain, or pray for drought," Commissioner Paul Thiede responded in jest.
"That's up to the engineers," Korchik said.
Thiede asked Westerberg for more specifics concerning the engineering of the replacement structure.
"I'm not an engineer ... but the problem with this (current) dam is (the water) goes around the end, and your earthen dam doesn't go all the way to the shore," Thiede said.
Thiede wondered whether the angled ends of the weirs would direct the water away from the troubled eastern bank.
Westerberg said although difficult to tell from the drawing, the elevation of the weirs angled up as they neared shore.
"The bank is going to be armored to protect that shoreline," Westerberg said.
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Thiede asked whether the elevation was high enough to prevent impacts along the shore farther east "10 years in the future when we've slowed that down."
Westerberg said he did not expect the design to cause issues farther east.
"The idea with this levee is to make sure this water, to try to keep all the water that comes into the Pine River, inside this channel area," Westerberg said. "It might back up this way downstream, but that's not as big of an issue."
Thiede said his concerns were alleviated.
"That does reassure me, that it is more than a 5-foot elevation," Thiede said.
The project is possible through a $399,935 grant awarded by the Minnesota Department of Natural Resources. The Conservation Partners Legacy Grant Program provides funds to conservation projects through the Outdoor Heritage Fund, established by the 2008 Legacy Amendment. Funds collected from the Big Pine Lake Subordinate Service District, a taxing district established in 2010 to pay for repairs to the dam, will cover about $50,000 of the costs.
The dam is owned by Crow Wing County-a source of consternation expressed whenever issues concerning the structure are discussed among commissioners. The taxing district was approved when the board said it would no longer fund repairs of the troublesome dam.
"I will again state my opposition to us owning this thing," Thiede said. "I think it's ridiculous that we're forced to own it. I've fought that fight as long as I could fight it, and I guess we're stuck with it."
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Crow Wing SWCD technician Beth Hippert said they explored the ownership conundrum once again, and came to the same conclusion-no one is interested in taking over ownership from the county.
In 2013, the board approved spending $16,000 on an engineering study, seeking recommendations on more permanent solutions along with potential funding sources.
The report completed by Short Elliott Hendrickson was used to show the need to replace the dam. Funding the report was a key to receiving nearly $400,000 for the county's constituents, Bray said.
"What that allowed the lake association to do is to actually go after those funds themselves," Bray added.
