From superstar to sewer: The path of the Minnesota River

There's really no excuse, folks. The way we're treating a Minnesota "superstar" is a tick or two below shameful.

I refer to the state's aging natural wonder — the Minnesota River.

The Minnesota was central in the region's settlement history, a highway to the interior of a territory that as a state would take the river's name. River sediments together with rich glacial till produced remarkable soil that still yields a cornucopia of sustenance.

In 1903, a visionary in the river town of Le Sueur founded a vegetable-growing and -canning operation that became a world-famous brand overseen by a jovial Green Giant.

Long before recorded history, this "superstar" was more dramatic by magnitudes than that other famous river, the Mississippi. Internationally, geologists still know the Minnesota as a wunderkind of forces that shaped fascinating landforms, a living laboratory for earth-science study and discovery.

For recreational explorers, the river's valley yields fossilized shark teeth (really!), along with petroglyphs and other artifacts of indigenous habitation over more than 8,000 years. There are outcroppings of pre-Cambrian gneiss dating back 3.5 billion years, among the oldest anywhere on Earth.

By any reasoned reckoning, the Minnesota River is deserving of superstar status. For several thousand years it rumbled and roiled, its miles-wide valley filled to the brim with meltwater from glacial Lake Agassiz, a monster that dwarfed today's five Great Lakes combined.

As late as 1800, a goose winging from Sleepy Eye, Minn., to Bismarck, N.D., would have flown over glistening pearls of ponded marshland extending to the horizon, tall grasses waving in near-constant wind and colossal swarms of buffalo.

Today, a small-plane pilot over the same route would see what some call a "black desert." In many places, a duck looking for a pond to raise a brood would have to bring her own tub of water.

Back when that goose flew, some 70% of the prairie was lush wetland; today it's 80% farm fields. Only slivers of original prairie remain.

The assault started in the mid-1800s, when European immigrants boarded small stern-wheelers at Fort Snelling, westbound on the Minnesota for a new beginning. Their routine was arduous: Build shelter, clear land, plow the prairie, plant seeds, repeat. To gain the planting space, dig a ditch and drain those darn "slough-holes" (the "pond" pejorative).

With relatively few settlers initially, it was all harmless enough. But in less than a century the few became multitudes, and their practices became a textbook "tragedy of the commons" (which ensues when individuals, each acting in rational self-interest, collectively deplete their common resource).

Today, tens of thousands of miles of ditches and drain tiles spare few "slough-holes." Small farms have grown ever larger, as have tractors (air-conditioned cabs, sound systems), planters and harvesters, and fertilizer applicators with ever-longer booms.

Why fertilize already fertile lands? Once, fields were planted with crop varieties in a regular rotation that managed to renourish the soil. But today's giant fields mainly grow just two crops, corn and soybeans, that deplete soil nutrients replaced by bathing fields with phosphorus and chemical nitrogen.

The result has been predictable. If some fertilizer is good, then more is better, with the excess flowing into ditches and tiles and carried to — where else? — the Minnesota River, where chemical-induced algae devour oxygen. The stew remains active down the Mississippi into the Gulf of Mexico, where nutrients from Midwest farms have created an ever-expanding, oxygen-free dead zone.

The same process of field runoff into the north-flowing Red River in a wide valley shared by Minnesota and North Dakota farmers is producing algal blooms in Lake Winnipeg.

In 1992, Gov. Arne Carlson vowed to make the "impaired" Minnesota fishable and swimmable by 2002. A noble try, but like all attempts to clean up the state's waters, it was plowed under by the combined power of big-agricultural interests.

Now, a quarter century after Carlson's vow to clean the river, the state's Pollution Control Agency has revealed yet another assault ("E. coli crisis along the Minnesota River," Feb. 17). It seems that bacteria from failing residential septic systems and uncontrolled animal feedlots have expanded the portion of the Minnesota that's unswimmable, unfishable — and unwelcoming.

Shockingly, many straight-pipe septic tanks still illegally dump raw sewage; nearly 1 in 5 systems in the river basin are rated an "imminent health threat."

Runoff loaded with nutrients, weed-killing agents and bacteria continue to ravage, degrading our superstar Minnesota River to a sewer status as it approaches the Twin Cities.

A few years ago, Gov. Mark Dayton won legislation to require 50 feet of buffer grasses on either side of drain ditches to soak up excess nutrients. Another good try.

But, on cue, the ag lobby got its legislative friends to exempt "private ditches," on the worn argument that buffers would cost farmers unfairly. Never mind that farmers escape the high, steadily rising public cost of upgrading wells and municipal water systems to cleanse unsafe nitrates produced by … farmers.

There are efforts by the state Department of Natural Resources, the U.S. Fish and Wildlife Service, Ducks Unlimited and dedicated others to turn things around, but relative to what needs doing, it's like spitting into a stiff prairie wind.

But, oh, what a glorious past, this Minnesota River.

With the last glacier in retreat, the natural northward flow of meltwater was blocked by ice, and the massive Lake Agassiz overtopped a natural dyke at present-day Browns Valley, Minn., sending torrents into the "River Warren" flowing toward present-day Mankato, where a moraine from an earlier glacial event turned the river sharply northeast to rendezvous with the Mississippi, then a minor stream.

A few rods east of modern-day downtown St. Paul, the River Warren gushed atop a limestone layer and formed a commanding waterfall — larger than Niagara. The gorge seen today from St. Paul upriver to Fort Snelling was created by the falls' migration. (That falls, now smaller, migrated up the Mississippi and formed the spectacular gorge between Minneapolis and St. Paul; the falls was named St. Anthony. The same process created several tributary waterfalls, including the still-active Minnehaha).

And about those shark teeth:

The rushing River Warren scoured deep to bedrock gneiss, whose swirling pink-black-gray bands on polishable stone is mined today as "Rainbow Granite" for monuments and decorative building facings. Outcroppings remain for hikers to traverse, but a drive-by view of the famous "Morton Gneiss" can be seen on welcome signs to Morton, Minn.

The Minnesota basin is a lamentable mess, with intractable political forces preventing common-sense solutions. At the same time, there are many places on the river around New Ulm and Granite Falls where canoeists can experience amazing scenery of heavily-wooded banks and steep cliffs.

The Minnesota today is a speck of its former magnificent self, and like an aging soldier the grand old river has faded — but it still rolls on.