DNR suggests taking Little Trout water to fix Powell Marsh

From the Lakeland Times

When the Powell Marsh was created in Vilas County through the construction of 14 miles of ditches and dikes 51 years ago, the motive was commendable: Create a home for wildlife dependent on wetland habitat.

But today, property owners on Dead Pike Lake, found directly downstream of the marsh near Manitowish Waters, say the Powell Marsh is doing more harm than good, a situation they say the Department of Natural Resources needs to remedy.

At issue is the accumulation of an oxidized iron substance known as iron floc in the man-made ditches that crisscross the Powell Marsh and eventually discharge into Dead Pike Lake.

The iron floc, according to members of the Dead Pike Lake Association, is not only a bright orange eye-sore obscuring the once-clear waters of the lake, but is also covering the sandy underwater bars where the lake's walleye population traditionally has spawned.

"We know that iron floc naturally occurs in the groundwater that flows into the lake," said Dead Pike Lake Association member Rev. Gale Wolf. "But, we also know that the discharged water we receive from the marsh compounds the floc problem exponentially."

As evidence, Wolf and other lake association members have collected Secchi disk readings throughout the past decade, demonstrating that during periods of low or no water discharge from the marsh, lake clarity levels increased dramatically from 7.4 feet to 13 feet.

When water was released from the Powell Marsh into the lake, water clarity again plummeted to as low as 4.8 feet.

"I love that marsh and I don't want to see it destroyed," Wolf said. "But, we also want the clean, adequate water the marsh was naturally intended to give us."

Marsh not working well

As part of an ongoing dialogue between the DNR and the Dead Pike Lake Association, the DNR held a public meeting at the Manitowish Waters community center in August to discuss the future of the Powell Marsh.

"Things are not working as well as they used to," said DNR area supervisor Chuck McCullough, referring to the marsh's extensive ditch and dike water control system.

Repair of the man-made system due to old age has admittedly been expensive, said McCullough, referring to an example several years ago when approximately one-half mile of the 14-mile system was refurbished at a cost of $160,000.

The ditch and dike system helps marsh managers control how much water is pooled in man-made ponds, how much remains stationary in the ditches and how much is released into Dead Pike Lake, said marsh manager Linda Winn.

By controlling the flows, she added, wildlife managers are able to provide the most suitable habitat for marsh wildlife such as ducks and geese, sharp-tailed grouse, sandhill cranes, wolves, fox and otters.

Effects were unknown, unstudied

Before the Wisconsin Conservation Commission directed the construction of the ditches and dikes in 1955, Winn said, the marsh was a swampy, tamarack bog that was periodically cleared of overgrown vegetation by natural wild fire.

In a cyclical pattern, Canada geese would flock to the marsh after a natural burn to feast on the
tender, new growth.

In an attempt to keep the geese population at the marsh year after year, the commission decided to manipulate the marsh into a waterfowl management area.

Because the ditch and dike construction took place years before the federal government began requiring environmental assessments for large projects, Wolf said, the high level of iron present in the soil was unknown and the effect the iron could later have on water quality went unstudied.

Due to the depth of the constructed ditches, groundwater flows under the marsh are intersected, forcing the groundwater to seep into the ditches and pool there.

While the additional water source is beneficial for marsh management, contact between the iron-rich groundwater and the air causes the iron to oxidize and form unnatural amounts of rust-colored floc, which finds its way into Dead Pike Lake when the ditches are flushed, said both Wolf and DNR representatives speaking at the meeting.

"There are a lot of shortcomings on the property right now," McCullough said at the meeting, "and we need to talk about what to do in the future."

Little Trout Lake water

What DNR water quality specialist Jim Kreitlow proposes for the marsh's future entails pumping more water through the man-made ditches in an attempt to suppress the creation of iron floc.

Kreitlow's proposal would not affect the basic function of the marsh as a waterfowl management area, and would allow the DNR to continue updating the antiquated water control structures.

According to Kreitlow's research, pumping more surface water - most likely obtained from Little Trout Lake, found just south of the marsh - through the ditches to maintain adequate water levels in the marsh would result in reduced groundwater seepage into the ditches.
Less groundwater finding its way into the ditches should mean less iron floc formation, he added, since the groundwater would stay either underground or would remain under the flowing surface water and out of contact with the air.

"The pressure of the surface water flowing through the ditches would suppress some of the groundwater and would shorten the retention time for water in ditches, therefore reducing the amount of time for the orange color to appear during oxidation," Kreitlow explained at the meeting.

Additionally, he said, any groundwater that does become oxidized and produce iron floc would be diluted with the iron-free surface water pumped through the ditches.

While Kreitlow said he has already experimented at the marsh with increased surface water flow through the ditches, he said there are unanswered questions as to the project's sustainability.

"We still have to look at whether we have enough water to do this," Kreitlow said.
Diverting water from Little Trout Lake for use in the marsh could prove problematic, said DNR regional water leader Tom Jerow, because part of the lake is on tribal land and the lake's water is used extensively to support the local cranberry industry.

There is also the possibility of finding enough water within one of the marsh's water impoundments rather than using water from Little Trout Lake, Jerow said. But any potential sources have not yet been identified and remain an "unknown," he added.

"To be frank, the issue will be a difficult one," Jerow said. "We plan to work with the tribe and the cranberry growers. But we do have a permit allowing the legal take of the lake water, and I suppose we (the DNR) could argue that we could just do it."

According to Jerow, Kreitlow is expected to finish a report on his proposal for increased ditch flows over the winter and increased flows, or construction to access water from Little Trout Lake, could begin as early as next summer.

Cart before the horse

But Dead Pike Lake Association president Pete Guzzetta said at the meeting that it appears the DNR is latching onto Kreitlow's proposal when other options have yet to be thoroughly explored.

"You are putting the cart before the horse here," Guzzetta said. "Why try these experimental flows before you even know if the water is available?"

Instead, Guzzetta said, the DNR should conduct an official environmental assessment on the marsh to determine if other options, such as letting the marsh return to its natural state, free of the water control structures, would better suit the entire watershed.

"When [Kreitlow] was experimenting with increased ditch flows, there may have been more clarity in the ditches on the marsh," Guzzetta said. "But during that time on Dead Pike Lake, we lost a foot of clarity in the bay [where the water discharges]."

Wolf also said he believes the DNR's reluctance to explore options other than what he refers to as Kreitlow's 'dilution solution' is troubling.

"Why do they simply want to mask the problems created by the marsh when they could find a way to fix the real, underlying problems?" he asked. "In recent history, with examples such as the Mississippi and Missouri river waterways and the devastation following Hurricane Katrina, I believe we have seen what happens when natural waterways are tampered with."

"Personally, I have been amazed to see what a marsh can do [to control water flows] with its own natural design," Wolf added.

Not a realistic option

Though Wolf and Guzzetta both maintain that the option of allowing the Powell Marsh to return to its natural state, free of the man-made ditches and dikes that control the flow of both ground and surface water through the 4,300-acre marsh, should at least be studied by the DNR, marsh manager Linda Winn said she has not considered the idea as a realistic option.

"Doing that, we would lose the impounded water, which provides a great value for waterfowl and rare birds," Winn said following the public meeting.

"We could potentially manage the marsh with prescribed fire, which would keep the landscape open and prevent the return of the tamarack bog," she admitted, "but I really haven't considered that possibility and don't know how it would work."