Last Saturday was a day some people living in and near Appleton, Minn., thought might never come. But it did, and a gathering in that town, population about 1,400, near the state's western border with South Dakota, demonstrates once again the power of persistence when natural resources and their conservation are at stake.

Among those on hand was Sen. Amy Klobuchar, D-Minn., whose help in Washington was crucial to the milestone being celebrated. The hard work of many others also was important, including that of local residents, from county sheriffs to small-town mayors, as well as officials from the state Department of Natural Resources (DNR) and a raft of concerned conservation groups.

At issue was Marsh Lake, all 5,100 acres of it, whose average depth is less than 3 feet.

Throughout most of recorded time, Marsh Lake was an oasis for all manner of migratory birds, especially ducks and shorebirds, as well as, more recently, Canada geese and white pelicans.

That was until the 1930s, when, for reasons that made sense at the time, a dam was built at the lake's outlet as part of the Works Progress Administration, or WPA — a Depression-era program intended to give people jobs. The dam was one of three built at the time on the Minnesota River to control flooding.

As part of the project, the Pomme de Terre River was rerouted to flow into Marsh Lake upstream of the 1,200-foot-long dam.

Taken together, the dam and the Pomme de Terre's changed course acted as a double whammy on Marsh Lake:

Where once lay a huge, shallow stretch of vegetation-rich water whose level fluctuated with the weather — completely dry during drought to overflowing at times during spring rains — now sat a stagnant cesspool of turbidity whose most plentiful resident species were common carp.

Dave Trauba, a regional wildlife manager in New Ulm, previously was the Lac qui Parle area wildlife manager who oversaw Marsh Lake and the wildlife-rich region surrounding it.

"I and a lot of other people worked to improve Marsh Lake the entire 24 years I was stationed there," Trauba said.

But not until Saturday was Trauba assured, finally, that his efforts and those of many others had paid off:

The Army Corps of Engineers announced it would spend $7.6 million of federal money, along with about $4 million of Minnesota Legacy Amendment money recommended by the Lessard Sams Outdoor Heritage Council, to replace the old dam with a V-notched weir at Marsh Lake. The new structure will allow water levels to fluctuate seasonally.

Additionally, a drawdown structure will be built that will allow wildlife managers to simulate periodic droughts, and the Pomme de Terre River will be rerouted to enter the Minnesota River below the dam.

Final project plans will be completed later this year, with construction contracts signed by early 2017 and work beginning shortly thereafter.

With luck, the Corps of Engineers, DNR and others will agree to draw down the lake during construction. Plans are to reduce it to 936 feet above sea level from its present 938.2 — enough to simulate the 1,600 acres of mud flats that were exposed in the 1976 and 1988 droughts.

The lower water level will produce multiple positive outcomes.

Sago pondweed — which ducks thrive on, and which was once prolific in the lake — is expected to return, and with it clean water.

Downstream, Lac qui Parle (the lake) will benefit, as will its fish, because the new dam will be constructed so all finned species, not just carp, can swim upstream into Marsh Lake, which is expected to act as a seasonal nursery for game fish such as northern pike.

Still in development is the DNR's Marsh Lake management plan, an undertaking that concerned conservationists should follow closely to ensure that periodic drawdowns of the lake will in fact occur indefinitely — something fisheries managers have been known to protest in the past.

"Marsh Lake didn't degrade overnight, and we're not going to solve these problems overnight," Trauba said. "I'd be lying if I said we know exactly how the lake will respond once we bring management to bear on it.

"But every time we do a drawdown, we'll put more of the pieces back together."

In addition to Klobuchar, Sen. Al Franken and Rep. Collin Peterson, fellow Democrats, were among Minnesota congressional delegation members who worked with the Corps to complete the project's funding.

Ducks Unlimited's Washington office also was a player, as was its state staff, headed by Jon Schneider, as well as the Upper Minnesota River Watershed District, administered by Dianne Radermacher, and many others, including individual conservationists such as Win Mitchell, a state DU volunteer leader who counts Marsh Lake and its environs among his favorite parts of the state.

Everyone's efforts had one goal, as Klobuchar said in Appleton on Saturday:

"To put the marsh back in Marsh Lake."

Dennis Anderson danderson@startribune.com