outdoors

LAC QUI PARLE WILDLIFE MANAGEMENT AREA — The Department of Natural Resources wildlife manager here, Dave Trauba, oversees a 33,000-acre, snow-covered complex that in a month will be flooded with water and migrating birds alike.

Most of the winged visitors won't stay long. En route farther north, they will arrow toward the Canadian border and beyond, and to North Dakota, where they will nest and rear their young.

Fascinated by this seasonal transition, and the shuffling of birds from south to north, Trauba will be on the lookout, first, for red-winged blackbirds (some are already at Lac qui Parle), and also for snow geese, mallards, canvasbacks, blue-winged teal, various species of shorebirds and, of course, Canada geese.

But not everything that gains his attention will be flying overhead. He will be alert also to changes the new season will bring to a unique portion of Lac qui Parle Wildlife Management Area, the 110-acre Killen Moist Soil Unit, named for Jim Killen, the Owatonna wildlife artist, and his wife, Karen.

Now in its fifth year of operation, the Killen unit is garnering heightened attention. Unexpectedly, in January, the DNR announced a shift in duck management strategy in Minnesota, saying it is exploring adding a number of similar "moist soil" management areas throughout the state in an attempt to aid a waterfowl recovery here.

Few Minnesotans know more than Trauba about the potential benefits of moist soil management (they appear to be many), or the challenges it represents (ditto).

It was Trauba's idea in 2003 to develop the Killen Unit, in conjunction with Ducks Unlimited, at a cost of $340,000. In the years since, he and his staff have encouraged it from infancy to adolescence.

And, yes, after the unit was built, ducks came, particularly during fall migrations, when its clean, clear, carp-free water and ample aquatic vegetation attracted these fowl like magnets to steel.

"It's amazing, really," Trauba said. "I don't know how they do it, but ducks will find food-rich areas."

• • •

Some background:

Before settlement, and before the state's prairie landscape was so dramatically altered by drainage, thousands upon thousands of Minnesota wetlands flooded in spring, dried up in summer and filled again, at least partially, in fall.

This natural cycle -- still replicated across much of the Dakotas in areas where grassland ranching is more common than row cropping -- nurtured the germination of aquatic plants upon which vast flocks of migrating waterfowl depended.

Necessary to the growth of these plants was the elimination of water -- the drying up of the wetlands -- in summer, followed by the moistening of the soil again in fall.

Today across much of prairie Minnesota, this cycle has been broken. So many wetlands have been drained -- more than 90 percent in some areas -- that remaining prairie waters in many cases have become connected, producing historically high water levels.

Worse, most of these waters are now home to millions of carp, a fish first imported to Minnesota about 1880.

Recall now the Killen Unit, which is modeled after scores of similar areas in mid-latitude states such as Missouri, as well as those in many Southern states

Dikes seal off each of these, into which water is either pumped or allowed to flow in spring, before being drained in summer and refilled in fall.

The goal is to mimic natural wet-and-dry cycles and to allow annual vegetation such as smartweed and pigeon grass to germinate before the areas are re-flooded in fall.

"Our first year, 2006, we saw an immediate response with ducks," Trauba said. "It was really impressive."

Some statistics:

• The flooded area of the Killen Unit is 110 acres, and it's surrounded by another 150 acres or so of buffer, all of which is a refuge where no hunting is allowed.

• The Killen Unit contains 1.7 miles of dike.

• Water is supplied by the adjacent 5000-acre Marsh Lake. Sixty-five million gallons of water are required to flood the unit -- a number that rises to about 100 million gallons when evaporation and other factors are considered.

• A 40-horsepower pump capable of pulling in 6,500 gallons of water an hour can flood the Killen Area in about 10 days. Dam-like structures control the outlet.

• Labor, electricity and other costs to operate and maintain the Killen Unit run about $4,000 annually, a sum paid for partially by state duck stamp funds.

• • •

If Minnesota is to benefit on a large scale from moist soil management, a series of Killen-like areas probably would have to stretch north to south along the state's western border.

Already DNR regional wildlife managers have asked their staffs to identify potential construction sites -- not an easy task, considering the multiple criteria required. Such as:

• Land already in public ownership of at least 40 acres is best.

• An adequate source of surface water. Best, and cheapest, are potential moist soil units that can be flooded and de-watered by gravity.

• Soils should be flat or gradually sloping, and clay, with no sand veins to cause leaking.

• Potential sites should be close to waterfowl hunting opportunities, with access to electricity.

"We begin drawing the Killen Unit down shortly after the spring migrants move through," Trauba said. "We like to have dry soils by late May or early June, so we can move out there with equipment by mid-June or early July."

Though Trauba depends primarily on the germination of natural plants in the Killen Unit, last year he and his staff planted five acres of corn, which was flooded. In previous years, millet was seeded.

So far, invasive plants such as reed canary grass haven't been a problem. But lessons have been learned in constructing and maintaining the Killen Unit, and if Trauba gets a chance to build a similar area, he'll do a few things differently.

"In the Killen Unit we have an area along one dike that always has five feet of water or so in it," he said. "That causes two problems: It's a place where hybrid and narrow-leaf cattails can take hold, and we don't want that. It's also where muskrats can live and constantly burrow into the dike."

These problems could have been prevented if the entire unit had been scraped nearly level during construction. Now -- at a cost -- the dikes could be retrofitted with riprap, Trauba said, which would eliminate the muskrat hassle, at least.

Bottom line?

"I am very confident that if we had a series of moist soil areas scattered throughout the state -- in addition to the work being done on the state's shallow lakes and other aquatic habitats -- we could attract more ducks," Trauba said.

"It's true that hunting might not be allowed on the units themselves. But nearby areas will see better hunting, I'm convinced. We already have, on Marsh Lake."

Dennis Anderson •  danderson@startribune.com