DNR raises new concern over lake water levels

State environmental officials have floated a new concern about fluctuating water levels on the Wolf River and Shawano Lake that could imperil a compromise reached last year over how much water should be retained at the Shawano dam, located just off Richmond Street in Shawano.

Based on boater safety concerns, an agreement was reached last year to maintain water levels at the dam during the summer at the volume they had been kept at for some 30 years.

It was agreed that water levels would be lowered during the fall and winter.

Now, however, the state Department of Natural Resources is raising concerns about what impact the changing water levels could have on fish spawning.

In a letter from the DNR to Shawano Area Waterways Management (SAWM), the agency wrote that DNR Fisheries staff has expressed concerns about what impact holding back water levels during the fall and winter months could have on the eggs and fry deposited in the grassy marches and rocky shorelines during the spring spawning season.

“While decreasing water levels happen naturally each year, the additional withdrawal of water from the river may have a negative impact on the success rate of the spawn,” the DNR wrote. “At this time, we do not have data to aid us in determining if an impact will be felt.”

The DNR has asked SAWM to participate with the DNR and two fishing clubs — Walleyes for Tomorrow and Sturgeon for Tomorrow — in a study aimed at determining the impact.

The study will require water level gauges to be placed in key rock and marsh spawning areas in Shawano Lake and below the Shawano dam, possibly as far downstream as Fremont and Lake Poygan.

The gauges would be monitored “over the next few years” to determine whether there has been any impact on walleye and sturgeon egg and larval success.

After that time, the DNR said, discussions over water levels could be re-opened if it’s determined those levels are impacting spawning.

The Shawano dam was mandated by the Federal Energy Regulatory Commission (FERC) in May of last year to reduce its target elevation from 802.9 feet mean sea level (msl) to 802.5 feet msl, resulting in a difference of more than 4 inches in the water level for the river, channel and lake.

The lower water levels resulted in multiple reports of damage to boats and near-injury while the new level was in effect.

A compromise was reached in June allowing the operator of the Shawano dam, Eagle Creek Renewable Energy, to return to a target elevation of 802.9 feet from May 25 to Sept. 15 each year.

The water level would then be lowered to 802.5 from September to May.

That agreement was not a permanent fix, however, and would have been subject to review even without the new spawning concerns.

The dam had been operating year-round at a target level of 802.9 feet for about 30 years before a single property owner complaint was filed in 2015.

SAWM board member Jeff Puissant said a final resolution and final approval to leave the water at the higher level in the off-ice months is still at hand.

“I feel like we’re moving in that direction,” he said.

Puissant said there’s no way to know what the impact on spawning might be until the study is done.

“You just like to hope that it doesn’t further delay our coming to a permanent resolution,” he said. “I feel like if we can continue to work with the DNR and bring in the two fishing groups that we can collectively come to a solution. The sooner we can wrap this up and put it to rest the better.”

Puissant said the original solution that was proposed, to keep the water at the higher levels year-round, ran into DNR concerns about floodplain mapping and flooding issues.

“So, we said, ‘Hey, what if we just raise the level during the navigation season,’” Puissant said. “It was kind of a happy medium.”

Puissant also said that waiting to raise the water level until May 15 should keep the spawning season safe.

“In most cases, it gets us passed the spawn season, so that’s why I’m thinking it should be a non-event,” he said.

Now that the first fall and winter under the agreement during which water levels were kept lower has passed, it remains to be seen what was accomplished, according to Puissant.

“I don’t know that there was a specified goal that they were hoping to achieve,” he said. “We thought maybe drawing that down a little bit will reduce ice shove damage and other things, so maybe there would be some type of carry-through benefit that would apply, but that didn’t occur. We still saw the same level of ice shove and shoreline damage.”

SAWM will hold its annual meeting Saturday at 9 a.m. at the Main Event in Cecil, at which time the group will seek volunteers and discuss how it will participate in the spawning study.

After that, Puissant said, “we’ll sit down with the DNR and the two fishing clubs to define the scope of the project.”