Parched by a Record Snow Drought, the Chicago River Threatens Reversal
It’s been a strange winter here in the Windy City -- even by Chicago standards. Long-time residents like me actually breathed a sigh of relief when significant snow fell during the past two weeks, leaving ice-filled ruts and slick streets behind. At least this was winter weather we could understand. Not like the two-month period after Thanksgiving when almost nothing white fell from the sky. Going back to last winter, Chicago went an unheard-of 355 days without an inch of snow accumulation -- the longest such “snow drought” in the city’s recorded history. Come January, arborists were urging residents to haul the hoses out of the garden shed and water their trees, lest they succumb to mid-winter drought. Unseasonably warm temperatures prevented ice from forming on Lake Michigan, and its levels, which have been decreasing for 18 years due to a number of factors, dropped to record lows. Then, as if all that weren’t strange enough, experts began warning that the city’s murky green iconic river could temporarily reverse itself.
Or actually, re-reverse itself would be a more apt description. As Matthew Power explains in OnEarth’s Spring 2013 issue (see “Cry Us a River”), the Chicago River is a misguided engineering marvel, forced by a series of locks installed in 1900 to run against nature’s course. A little over a century ago, the river was a clear and present danger to the city that bears its name, a sewage dump for the masses carrying pollution into Lake Michigan, the source of the city’s drinking water. Following the simplest of gravitational rules -- that water flows downhill -- the locks were designed to keep the river at a level lower than the lake, forcing it to flow in the other direction. Now, with lake levels dropping far below the point that early 20th-century engineers could have imagined, it has become increasingly difficult to hold back the river from returning, at least temporarily, to the direction it once followed.
As of January, when Lake Michigan was 17 inches lower than at the same time last year, engineers said that another six-inch drop was all it would take to suck the river backwards. The lake usually drops to its lowest point in February and March, meaning there’s probably still a ways to go before the lake starts to level off or recover. Snow melting at higher elevations usually starts to replenish the lake in April, but of course, there wasn’t as much snow this year, and long-term predictions call for drought conditions to continue at least through the spring. Even longer term, climate change could mean a lot more winters when Lake Michigan reaches new lows.
So what’s the problem with nature getting its way? Well, the Chicago River might not be as bad as it was in 1900, but it’s still full of bacteria from human waste that is dumped from water treatment plants. If lake levels do fall to the point of reversal, the locks would continue to hold most of the river back, only letting a small portion of dirty water through when they’re open for ship traffic. The real issue is that the river would no longer get fresh water from the lake and would become a lifeless, stagnant bog crossing the city’s heart. David St. Pierre, executive director of the Metropolitan Water Reclamation District of Greater Chicago, says if that happens, river traffic could be temporarily suspended until the situation rights itself -- however long that takes.
St. Pierre’s agency is meeting regularly with the Army Corps of Engineers to develop short-term contingency plans, but long-term, the only solution might be one advocated by the Natural Resources Defense Council (which publishes OnEarth): hydrological separation of the Chicago River and Great Lakes from the Mississippi River basin -- the source of those nasty Asian carp that have been threatening to invade the Great Lakes in recent years. Moreover, taking the steps needed to clean up the river would mean it wouldn’t matter if it began to flow backward into Lake Michigan again. With climate change threatening the Midwest with more droughts and severe floods, Joel Brammeier, president of the Alliance for the Great Lakes, believes we can no longer try to manage the region’s lakes and rivers to our whims. “We’ve been thinking about this river as engineers for a very long time,” he says, “manipulating the water where we want it to be, instead of letting the water go where it wants to go.”
Former Mayor Richard M. Daley, for one brief summer in 2000, sent gondolas afloat on the Chicago River’s currents, saying he was bringing a bit of Venice, a dash of class to the water. Gondoliers dressed in striped shirts and and ribboned straw hats regaled passengers in fake Italian accents. “You-a-know, this river, she flowa backwardz!” they cried. For now.