When I was a kid I loved to go down to the local park after a heavy rain. Water running down to the river in the channels alongside a dirt path could be dammed up with mud--for a few minutes. But water is relentless and eventually it will find a way to squirt through and completely destroy your work. It was wonderful, dirty entertainment for an eight-year-old. After a summer thunderstorm, I could get in a good couple of hours of hydro-engineering.  

I had no idea there were grown-up people with jobs like that.  

Some of them work out in the channel of the Mississippi River in downtown Minneapolis, in a boxcar-shaped building perched on the edge of St. Anthony Falls. They build river deltas, demolish dams, dig channels, and restore wetlands. And their next job is to help shape the future of renewable energy.

The building is the University of Minnesota's St. Anthony Falls Laboratory, and Fotis Sotiropolous is its director.       

"We are a living history of the Minneapolis waterfront�the only building around here that I know of that is still using the falls as a source of hydro power. To produce science," he says, "not flour."

Modeling Hydro-Happenings

He's not kidding.  People enter the lab on a walkway that passes over the supply channel that gives the Mississippi its own separate entrance to the place. (Even in this cold winter, the waterfall is producing a steady flow, though once in a while the scientists have to clear a little surface ice.)  

"The lab is unique," says Deborah Hudleston of the National Center for Earth-Surface Dynamics, a National Science Foundation Center housed at the lab. "The water falls the height of the building, which is the height of the falls, and goes into the bottom pool."

In between is where all the fun happens, as water is directed into flumes where University scientists, graduate students, and visiting researchers construct scale models of rivers and streams with gravel, sand, and charcoal.  They're using the Mississippi's waters to cut model channels and form faux deltas, all in the name of solving the river's real problems.  

Problems like algae blooms that create a "dead zone" in the Gulf of Mexico, and sediment trapped behind dams that should be spread out at the river's delta to bolster drowning wetlands.  

 "The most pressing problem that Louisiana is facing is rebuilding the delta," says Sotiropolous. "Can we use the best science to actually impact the way that you can re-grow land?"  

Re-growing land sounds Frankenstein-level cool, but it's serious science too. It involves detailed mapping of the way sediment collects and checking the results against sophisticated computer models.  

Some of the researchers work in "Jurassic Tank," a mammoth sandbox with bottom sections designed to sink (or not) in response to swirling water. The work area is a visual reminder that scientists and grad students are famously messy, and they don't throw anything away. A jellyfish-tentacle nest of power cords dangles above 1950's-era desks piled with 21st-century computer equipment--everything coated with a thick layer of dust from piles of dried sand being sliced for close examination. Nearby, a large white board is completely scribbled over with equations and charts. It all looks terribly smart and hopelessly intricate. 

"That's what makes the science of fluid mechanics really exciting," says Sotiropolous, "To try to figure out the complex rules that govern water flow."

What Water Can Do to a Laboratory

And flowing water is what brought me here. Though the river enters the upper levels of the lab by invitation, I find out that at ground level it's much less well-mannered.

"The building itself is designed to flood," says Hudleston.  "The river just comes in. And then it leaves. Every spring the basement is flooded and we know that it will be."  

The Mississippi is a bad house guest.  Seven decades of constant traffic from nature and graduate students has taken a toll.

"This is a crumbling building," says Sotiropolous.  "We have water running through it year round. We have pipe systems that are corroded�we don't have a working elevator. You don't' even want to look in some corners."  

Oh yes I do, but there's not enough time to examine the whole thing. As I gaze down from the top of a four-story-high central shaft, the jumbled clutter of pipes and machinery at the bottom level looks like the abandoned engine room of a doomed submarine. I fully expect Captain Nemo to come stumbling through with a giant octopus tentacle around his neck. But it's just Fotis Sotiropolous again, and he's got a plan to put things back in order thanks to federal stimulus money to remodel and update the place. 

The purpose of the update? Adventure! And a global challenge! 

Future Flows

The new mission, he says,  is "coming up with ways to power our civilization that are sustainable.  We are a fluid mechanics laboratory and therefore we want to find ways to develop research programs in areas of energy that intersect with fluid mechanics.  So we decided to focus on three forms of energy."

And those are: Wind power. Biofuels. Hydrokinetics.

Wind power is something I already know about, or think I do. I'm interested to hear there's a wind tunnel on the top floor of the lab where toy-sized turbines are arranged on a phony landscape, and then watched very, very closely.  I'm even more interested to hear that the lab has funds from the Department of Energy to build a full-sized wind turbine on University-owned land in Rosemount. And for the best possible reason--trying out stuff.  

"Can we go to a wind farm, to a developer who has spent millions of dollars and say 'by the way, shut down your turbine.  We want to take over for a couple of months to see what happens?' Sotiropolous asks before providing the obvious answer. "It's not going to work ...  so we are building this full-scale turbine. The idea is not to produce power, it's really to do research."  

Biofuels are the latest attempt to find a way to run our machines on juice from living things, as opposed to the dead-thing juice we've been using for ages. Sotiropolous tells me that algae secrete oil, which cements my strong feeling that I don't want to spend a lot of time around algae. Turbulence, he says, causes even more oil production.  Researchers at the lab already know a lot about algae blooms from their work in the rivers, and the people who work in fluid mechanics could lead a filibuster in the Senate with a mere fraction of what they know about turbulence, so biofuels are a natural area of focus for the lab.

The third area is hydrokinetics, which is not a health-club fad, but a way to get around building dams.  

Holding water back "created all kinds of issues," Sotiropolous says. In hydrokinetics, "if you have a river or stream where you have high enough velocities you can simply put some type of a turbine in there to spin, like an underwater wind turbine."

I like the idea of a submerged wind turbine, especially when he tells me the lab has joined with a company called Verdant Power to test ideas for the technology in New York City's East River. Generating Manhattan's electricity underwater sounds wonderfully dangerous to my inner eight-year-old.      

Clearly the people at the St. Anthony Falls Laboratory have found a way to turn stuff that is wildly fun into something of real value--useful scientific knowledge and the possibility of a future with reliable, renewable energy.  More power to them, I say, and perhaps that will bring more power to the rest of us.

As the Resident Tourist, Dale Connelly introduces readers of The Line to out-of-the-way points of interest in the Twin Cities. In our November 16, 2010 issue, he took in the classic movies and classic ambience at the Trylon Microcinema. For many years he was the co-host of Minnesota Public Radio's Morning Show.


Photos, top to bottom:

The Laboratory sits right next to Saint Anthony Falls.

Fotis Sotiropolous, head of the lab and hydro-expert.

Mississippi water flows into the laboratory, where experiments are created.

Looking down into the lab's depths

All photos by Bill Kelley