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Miron Construction Co. of Neenah is restoring the Little Falls Dam on the Willow River near Hudson at a cost about $19 million.

HUDSON — Despite heavy rain setbacks this spring, restoration of the Little Falls Dam on the Willow River at Willow River State Park remains on schedule for “substantial completion” around Dec. 18, 2019, according to a Department of Natural Resources official.

Refilling of a 172-acre lake to be formed by the new dam is going to be weather dependent, but should occur sometime in early 2020, said Cameron Bump, DNR’s recreation liaison in Eau Claire.

“We want to make sure that there is a minimum base flow in the Willow River,” Bump said. “If we happen to have a dry fall, it could take some time to fill the basin. There are some timing restrictions to protect fish and wildlife in the Willow River.”

Fish habitat improvements will include rock boulder piles, fish cribs and tree drops and eventually tree drops and stocking of fingerling and catchable-sized walleyes and smallmouth bass. No dredging is planned above the dam, but a small sediment basin below the dam will be dredged, Bump said.

Miron Construction Co. of Neenah is handling the project, expected to cost about $19 million, that was approved by former Gov. Scott Walker and the state Legislature.

“The construction bid was less than that, but there is engineering and other costs (including road paving) that go into the project,” Bump said.

Over the past several months the contractor was repairing flooded cofferdams around the dam and by-pass culverts to the Willow River, Bump said. Currently the contractor is pouring concrete to gate abutment walls and spillway slabs. When completed, the dam’s design will allow park staff to adjust depth at which water passes through the gates, thereby managing water temperature downstream for coldwater species like brown trout.

A 2013 study revealed a previous dam could not meet 100- and 1,000-year flood safety requirements to meet state and federal regulations. Thus it was rated a high-hazard dam because of threats to occupied structures downstream. The lake drawdown began in 2015.

Two other dams on the river have been taken out — the Willow Falls Dam in 1992 and the Mound Dam in 1997.

Citizens were concerned that removing the Little Falls Dam and the lake would have significant economic impact on the area. The park is one of Wisconsin’s most heavily used for day trips and overnight camping. Figures provided by the DNR show that since 2011 attendance has nearly doubled: 514,500 in 2011, 633,660 in 2012, 646,443 in 2013, 721,480 in 2014, 810,000 in 2015 (lake was drained in summer), 912,290 in 2016, 936,895 in 2017 and 930,580 in 2018.

“While the numbers for the first half of 2019 aren’t in yet, it is shaping up to be similar to recent years,” Bump said.

Paving of roads in the park will begin in November after heavy construction work is near its end. A new bathhouse costing about $480,000 was constructed at the park before the lake was lowered in 2015.

“The public has been excited to see this happen,” Bump said. “They want fishing and nonmotorized (boating) like they had before. Next summer it should be back.”