Protecting the 'sponge': Preserving forests in Mississippi headwaters boosts water quality

Stand on the banks of Indian Jack Lake, and you wouldn't know you're on the eastern side of the popular Brainerd Lakes Area tourist hub.

The serene lake is protected by woods of oak and birch trees, and it's ringed mostly with cattails, not houses or cabins. A flock of ducks soars overhead, and a beaver has gnawed away at some of the tree trunks.

There's another reason this property is valuable: Just a short distance away, the Mississippi River snakes through this forest. And protecting this land from being developed is part of a program called Mississippi Headwaters Habitat Corridor Project, aimed at preserving forests in the headwaters region.

The nonprofit Trust for Public Land recently bought a 235-acre site here that curves around the lake and donated it to the Minnesota Department of Natural Resources, permanently preserving two and a half miles of precious shoreline.

Undisturbed land like this is becoming increasingly rare, said Will Cooksey, senior project manager with the nonprofit.

"This area is experiencing greater growth, development pressure and conversion of natural spaces like these to other uses," he said.

The crucial forest sponge

The Mississippi River starts at Lake Itasca in north-central Minnesota. From there, it flows about 2,300 miles to the Gulf of Mexico. And for its first 400 miles — from the headwaters down to Little Falls, Minn., — the river winds through forests dotted with some of the state's most prized fishing and recreation lakes: Winnibigoshish, Bemidji, the Whitefish chain.

Experts say those forests play a critical role in protecting the water quality of the Mississippi and the lakes and rivers in its watershed. They act as natural sponges, collecting rainfall, filtering it and letting it soak into the soil, recharging the groundwater supply and helping keep sediment and nutrients out of lakes and rivers.

"What forests are really good at is putting water in the ground," said Dan Steward, watershed coordinator with the Minnesota Board of Water and Soil Resources. "Most forest situations don't have surface runoff. It's all going in the ground."

That's a good thing, Steward said, because the water doesn't have a chance to collect sediment and pollutants as it moves across the land. Contrast that to agricultural or developed areas, where stormwater washes over fields or pavement, washing pollutants into rivers and lakes.

"As you develop more and more of the watershed or harden the surface, you're switching [the lake] from groundwater-fed to surface water-fed," Steward said. "It's picking up more nutrients. The lake can take so much of that before it starts to decline."

Researchers have found that protecting a "sweet spot" of 75 percent of the forest cover in a lake's watershed helps maintain good water quality, Steward said.

The most important benefit of forests is "what they're not," said Bonnie Keeler, an environmental science professor at the University of Minnesota's Humphrey School of Public Affairs.

"It's the fact that they're not agriculture. They're not development," Keeler said. "It's really what land uses are not there. That's the biggest driver of why we still have high-quality water in most of the Mississippi headwaters region."

The Mississippi provides drinking water for about 1.7 million Minnesotans, plus about 18 million more people living downstream, Keeler said.

Right now, the water in the upper Mississippi is relatively clean. Farther downstream, the river faces some significant challenges, like the polluted runoff from farmland that leads to a Dead Zone in the Gulf of Mexico every year.

A rare opportunity to protect, preserve

In other parts of Minnesota, state and local agencies and nonprofits are working to clean up lakes, rivers and groundwater already polluted with high levels of nutrients, bacteria, chloride from road salt or other contaminants.

In the headwaters region, those same groups see a rare opportunity: to keep a relatively pristine watershed in its current condition.

It costs far more to restore water than it does to protect it, said Paula West, who coordinates the joint Mississippi Headwaters Habitat Corridor Project. "We're spending millions of dollars in Minnesota to try to restore waters in southern Minnesota that can never be restored. So where's the best bang for our buck?"

In the headwaters, the forests are helping keep the river clean — at least for now. But this region is Minnesota's cabin country, and it's facing serious development pressure.

In the last couple of decades, more people are retiring and turning lake cabins into larger year-round homes, said Tim Terrill, director of the Mississippi Headwaters Board, an eight-county joint powers board formed in 1980 as an alternative to federal control to protect the first 400 miles of the river.

This stretch of the Mississippi headwaters region faces another threat, too: Forests in the Park Rapids area have been cleared to plant potatoes and corn. They require significant nitrogen fertilizer that also can pollute lakes and rivers.

A focus on high-quality land

In an effort to get ahead of those risks before they become reality, the Board of Water and Soil Resources teamed up with the Trust for Public Land and the Mississippi Headwaters Board on a habitat preservation program that runs through 2021. With the help of an $8.5 million grant from the state's Lessard-Sams Outdoor Heritage Council, the program focuses on protecting land that is close to a lake or river, especially if it's adjacent to other public land.

Sometimes conserving the land meaning actually buying it, as in the case of the Indian Jack Lake property, which is now a wildlife management area run by the state DNR. Other times, a landowner signs an easement agreeing not to develop or crop-farm the land, although trees can still be harvested.

David and Virginia Parent signed a conservation easement for their 170-acre tree farm, which sits on the Mississippi River near Cohasset. The Parents have managed the forest for years, planting spruce, Norway pine and oak that provide habitat for deer, bear and other wildlife.

"It makes us feel good that we were able to benefit from the sale of the easement, and the fact that it wouldn't be all crowded and broke up into lots," David Parent said.

So far, the partner groups have purchased two properties and secured 10 easements, permanently protecting a total of 1,600 acres and 12 miles of Mississippi River shoreline.

In the past, efforts to acquire private property for public use have met resistance from local government officials, who don't like the idea of losing revenue from their property tax coffers.

But this project has gotten support from local officials like Neal Gaalswyk, a commissioner in Cass County, home to more than 600 lakes and about 30 miles east of the headwaters. He said taking property off the tax rolls is always a concern, and Cass County tries to maintain a balance by selling off county-owned property that would be better suited for private use.

But the county's tourism industry depends on clean water, Gaalswyk said, and sometimes, the benefit of protecting land outweighs the lost revenue. And county boards — which have to sign off on the land transfers — so far have agreed.

"People who live in areas where water quality is an issue — where the lakes are green, where they have algae blooms, where it's nothing but open prairie land and there are no trees," Gaalswyk said. "Those folks come up here to vacation, and they really value it up here."