For decades, the Illinois River has felt the impacts of a region on the rise.
There’s a reason the City of Peoria is located in central Illinois: water. The Illinois River and Lake Peoria lie at its heart, a symbol of both its historical identity and future prospects. This great waterway connects Peoria to the ports of Chicago and St. Louis, and from there, to the rest of the nation and the world. But despite the tight connection between the river and its people, the Illinois hasn’t always been revered as the great asset it is—nor treated as a resource worth protecting.
Industrial and Agricultural Development
By the mid-1900s, development of the Illinois River Valley, including the Peoria area, was driven by a population of three million people. The river and its vast variety of aquatic habitats formed a tremendous natural resource for those who were busy building farms, industries, and their supporting businesses. Recreational opportunities and commercial harvest produced millions of pounds of fish, bottomland wood and waterfowl. The commercial harvest of fish alone made up the second largest inland fishery in the United States. This era was known as a “period of plenty” for the river’s plentiful food and beautiful environment, but it was short-lived.
As human populations exploded in the 1960s, the region and the river changed, with large increases in industrial production upstream in Chicago, and sharp rises in barge shipping following the completion of dams on the Illinois and Mississippi rivers. Agriculture was booming as well, as the construction of levee districts allowed some three quarters of the floodplain to be drained. But while agriculture was growing, the draining of the floodplain greatly reduced the quantity and quality of river habitat.
During this period before the Clean Water Act (CWA), the tradeoff made for development was the degradation of the river. In the upstream reaches, the only fish caught regularly for years were common carp and goldfish. Eventually, the water was no longer drinkable or swimmable—let alone safe for fish consumption.
Traffic on the Waterway
In the decades following the CWA’s passage in 1972, the economy became largely focused on river navigation, as continued barge traffic drove the need for improvements to locks and ports. By 2001, some 30,000 barges carrying 30 million tons of cargo—including approximately 50,000 bushels of corn and 500,000 gallons of petroleum—traveled the Illinois River past Peoria.
Barges proved a far more cost-effective way of shipping bulk commodities than rail. Between 2000 and 2002, moving a ton by barge averaged $8.37, while by rail, the cost was nearly a dollar more, at $9.23 per ton. These simple economics led to increased barge traffic year-round, boosting the river economy. In 2011, for every ton it received, the state of Illinois shipped nearly four tons out of the state by barge. That same year, the total for the entire Mississippi River navigation system (of which Peoria and the Illinois River are integral parts) included 37.4 million tons moved by river, totaling $9.2 billion. The predominant commodities being shipped included coal (37 million tons), grain for domestic consumption (24 million tons), and petroleum (eight million tons).
And barges are not the only traffic on the waterway—it’s estimated that an additional 2,000 recreational boats pass through the locks each year in Peoria. And there are other, less obvious river uses as well. For instance, Peoria gets about half of its municipal water from the river, and a number of power plants in the region use river water for cooling purposes. In addition, there are tourism interests, represented by the Illinois River Road National Scenic Byway and the region’s various municipalities.
Accumulated Stress of Growth
In time, the accumulated stress of decades of development needed to be addressed. The passage of the Clean Water Act was the first step in coming to terms with the effects of growth on our waterways. Fortunately, today’s post-industrial era is a period in which reductions in sewage and waste as mandated by the CWA, combined with shifts away from a single-minded reliance on agriculture and industry, have dramatically improved the aquatic environment. Highlights include the steep decline in invasive common carp since the CWA went into effect. At the same time, recreationally important channel catfish and sauger have increased substantially, thanks to large reductions in point-source pollutant discharges.
But there are some newer problems for fisheries resources, including non-point source pollution and erosion issues related to land use and farming techniques. For instance, recent estimates suggest that more than 13 million tons of sediment from soil and bank erosion make it into the Illinois River each year. Pesticides and other chemicals attached to soil particles can kill or severely injure populations of aquatic organisms. Further, these particles turn clear water murky, damaging beds of aquatic vegetation that are critical for young fish, and filling in the backwaters used by adult species to survive winter freezes, summer droughts and major floods.
Biological pollution is a problem as well. Invasive species like the zebra mussel and Asian carp, for example, have caused serious issues for native fish, power plants and even recreational boating. While many commercial fishermen now harvest Asian carp for foreign and domestic markets, several recreational species like largemouth bass are showing early signs of decline.
There’s also been a realization that the rhythm of the river has changed, likely resulting from expanded navigation dams and levee systems. These changes influence the timing and duration of the annual high and low-water periods, which influence vegetation, fish and waterfowl. Normally, the river rises in the spring, bringing water to critical fish spawning and nursery habitats, and helping to maintain the moist-soil vegetation relied upon by waterfowl during seasonal migration. But in the last three years alone, several 50-year historic floods have wreaked havoc on these patterns. This changing climate, paired with new levee construction and lock and dam operations, has shifted the potential for a “spring flood” to occur at any time of the year—as evidenced by the floods of April 2013, June 2015 and December 2015.
New Solutions, Fresh Opportunities
But navigation has also brought opportunity. A great example can be seen in habitat enhancement projects like the two-decades-long partnership between the IDNR and the U.S. Army Corps of Engineers to build the Peoria Lake Upper Islands, completed in 2013; the proposed north and south Pekin Lake projects; and the Ten Mile Creek and Senachwine Creek projects.
The result of such projects has been a resurgence in people’s connection to the Illinois River. This renewed interest encompasses tourism potential, as seen in the revitalization of riverfront properties like Bass Pro Shops; in the missions of organizations like the Illinois River Road; and in economic diversification efforts, such as the potential expansion of commercial fishing and subsidiary industries explored at the 2015 International Asian Carp Conference, held in Peoria.
Each decade, the waters of the Illinois River adjust to the growth and life of the Peoria area, its business and its citizens. Whether as a lumberyard for building, a transportation artery for people and goods passing between the Great Lakes and the Mississippi, or as a source of rich farmland in the middle of the nation’s breadbasket, the river has always accommodated our changing needs. And as we continue to recognize the river’s health is essential to our ever-shifting intentions, there’s no doubt its best may be yet to come. iBi
Andrew Casper is Director of the Illinois Natural History Survey’s Illinois River Biological Station (IRBS) in Havana and a research biologist with two decades of field experience and background in freshwater ecology and coastal oceanography. Jason DeBoer is a research biologist with over a decade of field experience and background in freshwater ecology and fisheries science, and a large river fisheries ecologist at IRBS. For more information, visit inhs.illinois.edu/fieldstations/irbs.
