Bids for natural rapids replacement of dams expected mid-October
Dams are beginning to “drop like dominoes” on the Pelican River, from rural Detroit Lakes–all the way to Fergus Falls.
Two more will essentially vanish from the Lake Lizzie and Prairie Lake landscape by next summer.
Dam modifications are the easy part–a few hundred thousand bucks, some heavy equipment, and a dose of hydrology and river science is all it takes.
The hard part falls on Prairie Lakers Roger and Peggy Mayfield and Al and Carol Kuvaas–who will need to reassure skeptics that altering existing dams will not affect lake levels any more than Mother Nature does, in high and low water cycles.
Meanwhile, Kim Janecky has a similar assignment with the Lizzie Association members. Generally, there has been little vocal opposition around Lizzie, based on annual meeting discussions last summer. But Prairie Lake, because of its generally shallow structure, has drawn more scrutiny.
There are plenty of people who are sensitive to dam modifications, in the wake of the scrutiny over the Pelican Rapids city dam–which is now scheduled, though there are still skeptics on the impacts of the removal of the iconic city-owned dam.
A room full of interested parities gathered at the VFW meeting room Sept. 18 to discuss the Lizzie-Prairie dams.
Timeline for the dam projects, and the funding, has already been set. Bids are expected to be turned in by October. Construction is slated for late fall of 2019 to winter of 2020. Total project cost is estimated at between $300,000 and $400,000, at no cost to local Lizzie and Prairie taxpayers.
Modifying dam structures to return rivers to a more natural flow has been a priority of state and federal conservation officials. River scientists advocate projects in order to improve habitat, increase natural spawning of fish, and allow free passage of aquatic species up and down stream.
The modification of the Fish Lake dam, on the Pelican chain, was completed last winter. Within literally a day of completion, walleyes and northerns were already running through, said Howard Fulhart, Minnesota DNR-Fergus Falls.
“It’s one of those situations where ‘build it and they will come’…It was like the fish were just waiting to move downstream,” said Fulhart. By June, redtail chubs–a favorite bait fish for anglers–were spawning in the recreated rapids at the former damsite.
The Pelican Group of Lakes Improvement District is chipping in $75,000 toward the Lizzie-Prairie projects. Last year, the Fish Lake dam modification project was completed at about $270,000. It came in $75,000 below budget. Initial estimates were as high as $400,000.
“When’s the last time a government project came in under budget?” said Elshaug, who said the quasi-governmental Pelican LID worked “ten years to get rid of a deteriorating, 80 year old dam” at Fish Lake.
Instead of turning the spare money back to the state, Pelican LID official Jay Elshaug said the board preferred the money stay to benefit local waterways. The DNR agreed, and the money will be applied to the Lizzie-Prairie projects.
Interestingly, the modification of the Fish Lake dam on the Pelican chain is becoming something of a model for other projects around the state, said Elshaug.
The “rock arch rapids” that replace traditional dams “look natural, but they are actually very engineered,” said Moriya Ruther, Houston Engineering, who with Erik Jones, outlined the Prairie Lizzie plans.
Without getting into the detailed science, the rock and boulder rapids are all constructed to a “set point” that matches the current “crest” of the existing dams. The cubic foot per second water flow and elevations are measured. Using GPS and other scientific means, the natural “rapids” are designed to essentially recreate the existing dams, according to Jones, and Howard Fulhart of the Minnesota DNR offices in Fergus Falls.
Houston Engineering is the same firm that is working on the Pelican city dam modification, in downtown Pelican.
Houston will be monitoring the effects of the dam modification for at least a year, based on the contract, noted Jones. The DNR, which actually owns both the Lizzie and Prairie dams, is also responsible and will make adjustments in the natural rapids construction if there are unexpected consequences, said Fulhart.
The natural rapids design is intended to allow non-motorized traffic, such as kayaks and canoes. But not power boats and pontoons.
Locally known as Hosterman’s Dam, much of the Lizzie dam’s concrete structure will remain–with the modifications installed over the top and along the shoreline.
“Placing a cap on a tooth” was how Elshaug described the modification.
Prairie Lake has additional challenges, as the Pelican River runs under Highway 59. The design calls for a natural rapids on both sides of the highway
The next meeting on the Prairie-Lizzie dam initiatives is expected in October, after bids are received.