Drive south on Ill. Route 25 along the Fox River from the Kane County line during the coldest winter months and you won’t help but notice that the farther you travel into Kendall County the more the amount of ice on the river increases.
Granted, the river from the Montgomery dam south to Oswego is generally swift moving and dotted with small rapids, but swift-flowing water isn’t the reason the Fox doesn’t freeze over, because it used to just a few decades ago.
So what’s the reason for the open water until you nearly reach Yorkville?
The main answer seems to be that the largest tributaries of the Fox River these days are not those creeks, springs, and wetlands created by the last Ice Age. Instead, we are the river’s largest tributaries—the men, women, and children who live in the Fox Valley.
When the 18th Century ended, it was less than three decades until the first permanent white settlers arrived in the Fox Valley. As 1799 turned into 1800, the river’s largest tributaries were the creeks that drained thousands of acres of wetlands that dotted the river valley from Wisconsin to the mouth of the Fox on the Illinois River. In Kendall County, the largest of these subsidiary streams were, from north to south, Waubonsie Creek, Morgan Creek, Blackberry Creek, and Big Rock Creek.
Most of these creeks were the main outlets for large wetlands. Waubonsie Creek, for instance, drained the Wabausia Swamp on the Kane-Kendall County border, a wetland that covered nearly a square mile. Morgan Creek, too, drained extensive wetlands that were the remains of a former glacial lake.
Both north and south, other smaller and larger streams and springs added their flows to the river.
During the winter months, the water that seeped and flowed into the river from its bordering wetlands and tributary creeks was cold, having been pre-cooled as it slowly made its way to the river.
As soon as the settlers arrived, they began to wage war on the Fox Valley’s expansive wetlands. Over a 50-year period, they aggressively drained marshland and channelized streams, the former to create more farmland and the latter to drain stormwater into the river as quickly as possible to stop nearby farmland from flooding. Their efforts were extremely effective, even given that all the earliest drainage work was completed by animal power and hand labor. By the start of the 20th Century, drainage efforts continued, now assisted by steam-powered dredges.
The result was the addition of additional tillable land, and the elimination of wetlands that were homes to hordes of disease-carrying insects. Drying up the county’s numerous marshes and sloughs led to a precipitous decline in the occurrence of malaria—called “the ague” by the settlers.
But a major unintended consequence of all those drainage efforts was that they not only sharply decreased the summer and winter flows of the river, but they also led to more frequent flooding. That’s because the stormwater “banks” created by the county’s wetlands and meandering streams were eliminated. Instead of runoff trapped in sloughs and marshes slowly soaking in to recharge ground water supplies and be slowly discharged over a period of weeks following rainstorms or snow melt, the runoff was rapidly channeled into the Fox River where it flowed downstream to the Illinois River. When dry months arrived, there was no water “bank” to add to the river’s flows, and it nearly dried up during some dry periods.
In addition, the velocity of the water from the Fox’s tributaries greatly increased due to the elimination of meanders in the streams—channelization—and the disappearance of the wetlands that once slowed the speed of stormwater runoff. That resulted in farmland drying out much more quickly after precipitation fell, but it also resulted in more erosion, with the area’s incredibly rich topsoil washing into the fast-flowing channelized streams. The fast-flowing muddy water caused major flooding far more frequently.
And then, as the 19th Century ended, a new sort of tributary started adding to the river’s flows, this one far from the crystal clear water that was once generated by wetlands and meandering creeks. In the early decades of the 20th Century, it finally became apparent, that simply dumping raw sewage, from human waste to industrial products, didn’t get rid of the problem; it just moved it downstream. The human, animal, and industrial waste pumped directly into the river began to be treated to greater or lesser degrees as recognition of the dangers of pollution became clearer, and as wastewater treatment technology advanced.
With the Fox Valley’s population growth, the increasing volume of body temperature sewage began raising the river’s temperature, but at first there wasn’t enough inflow volume to noticeably affect it. As late as the late 1960s, the river regularly froze over all the way from Aurora south to Yorkville. When I was in high school in the early 1960s, we regularly ice skated on the river from Oswego north to Boulder Hill, a distance of three or so miles.
But shortly after that, as my friend, Dr. Paul Baumann, pointed out in his 1976 monograph, A Bicentennial History of the Fox River, by the time we celebrated the United States’ 200th birthday, about one-third of the water in the Fox River had already been used at least once by humans or businesses by the time it reached Kendall County.
And then came the Fox Valley’s explosive growth from the 1970s into the first decade of the 21st Century. With that growth, it’s likely the river’s single largest tributary has become the sanitary sewage treatment plants lining the river’s banks. And the relative warmth of that water (it’s slightly warmer, but no less pure than water already in the river thanks to modern wastewater treatment technology) means that nowadays the river seldom freezes between the Fox Valley Water Reclamation District’s huge wastewater treatment plant, located across the river from Boulder Hill, and the pool created behind the Yorkville dam.
As shallow as it is now and historically has been, the Fox River was never a main transportation route, but its dams did provide power for mills, its waters were rich in clams harvested for freshwater pearls and shells for buttons, and in winter its ice was harvested for use in both the home and industry. In fact, huge ice harvesting operations were conducted at each of the dams across the river, including at Yorkville and Oswego. How huge? In 1880, the Esch Brothers & Rabe ice company shipped 581 railcars of ice from Oswego. Of that number, they shipped 124 railcars full of ice from Oswego in August alone. By 1884, the ice company was shipping nearly 1,100 railcars of ice annually.
It’s fortunate cooling technology advanced so far that we don’t require that ice today, because through the impact on the environment of our mere presence here in the Fox Valley, we’ve managed to raise the river’s average temperature so much that it seldom freezes along much of its length in northern Kendall and southern Kane counties.