Summer 2004

Giving a Dam for Wild Rivers

Every river in Chicago Wilderness is dammed.
Now scientists are asking
whether it's time to break them free.

By Robert Heuer

Stroll along Batavia's Riverwalk on the Fox River in southeastern Kane County, and you hear an endless roar of water rushing over the North Batavia Dam.

A 10-foot-tall, 357-foot-wide concrete strip, the dam was built a century ago to power the machinery of a windmill factory. The factory is now occupied by businesses serviced by conventional electricity sources. But its stone façade bears a banner that reads "Keep the Batavia Dam."

Last February, the Batavia City Council voted to support the Illinois Department of Natural Resources' (IDNR) $8.6 million plan to tear down the dam and reconfigure this stretch of the Fox. This project — the first large dam removal in Illinois — could begin by 2006. Located in the heart of downtown Batavia, the dam has become a focal point in the debate about what's best for the rivers of Chicago Wilderness and the people who live along them.

Communities regionwide are facing decisions. Five years ago, in Kendall County, the Oswego Park District removed its damaged Stonegate Dam on Waubonsie Creek. Kane County removed the YWCA Dam on Brewster Creek this year, while the Kane County Forest Preserve District is finalizing plans to remove Batavia's breached South Dam.

In Wisconsin, which leads the nation in dam removals, a coalition is working to remove a critical dam on the Pike River in Kenosha County. All of this signals a growing awareness about the importance of healthy river ecosystems. Yet, as the City of Batavia discovered, people grow attached to their dams. Dam removal advocates have much work to do in building popular support for an asset, and an issue, that people usually see only on its surface.

Evolution in Understanding
The aging of America's dam infrastructure, combined with a mounting interest in ecologically oriented policies, explains why 114 dams have been torn down nationwide since 1999, according to the organization American Rivers.

"We've known for a long time that dams have a negative effect on rivers' health, but the real shift has come since passage of the federal Clean Water Act in the 1970s," IDNR streams biologist Steve Pescitelli explains. "Rivers are a lot cleaner now and capable of supporting a lot more fish. But fish need to have access. In northeastern Illinois, where there are so many dams, removal is the most effective way to complete the return on investment for river restoration."

Several years ago, IDNR launched a survey to evaluate the effects of dam removal and modification in Illinois. Its benchmark is a Fox River fish passage study by the Dundee-based Max McGraw Wildlife Foundation. The study was co-authored by Victor Santucci, now a fisheries biologist with IDNR's Office of Resource Conservation, and Stephen Gephard, a fish passage specialist from Connecticut.

Finished in 2001, the study evaluated the cumulative effects of 15 dams on the Fox River system in Illinois. (Eleven of these are in Kane County, including a 14-mile stretch with eight dams.) Dams cause a river to widen just upstream in what is called an impoundment. According to the study, more than half of the Fox's total surface area is impounded by dams. Unlike those designed to hold back giant reservoirs for flood control, most of the dams on Chicago-area rivers are low-head dams originally built to generate power at mills. They slow water, but don't stop it.

Over two years, Santucci took sediment, fish, invertebrate, and water samples, in addition to detailed habitat observations, from 40 Fox River stations. The stations were located in both free-flowing and impounded reaches of the river.

Santucci found dramatic differences. "On average, the natural flowing river had more species, four times the number of individuals, double the number of harvestable-sized sport fish, more suckers, darters, and [sensitive] fishes, a higher percentage of [insect-eating] minnows, and a lower proportion of diseased individuals than impounded areas," the study reported.

The scientists also discovered that 30 species of fish known from the drainage were no longer found in certain dammed sections of the river. Some species were absent from the heavily dammed middle reaches, while others-including sauger, American eel, skipjack herring, mooneye, speckled chub, longnose and shortnose gar, and the big-mouth, black, and small-mouth buffalo-were restricted to the lowest reaches of the river.

	Fish of the Fox: Candidates for a Comeback?
	Illustrations by Joseph R. Tomelleri. Not to scale.

The fish have vanished, Santucci contends, in part because dams impede their movement. (One joke circulating in Batavia goes, "Q: What did the fish say when it got to Batavia? A: Dam!") Dams prevent fish from migrating into breeding areas, from leaving unsuitable living conditions, and from replenishing depleted local populations.

But there's also the question of water quality. "Dams create a lake-like environment where water stagnates," says Santucci, "and sediment, which is normally moved downstream by current, collects on the river bottom." River advocates point out that dams often concentrate the effects of other problems such as polluted runoff and erosion. "Nutrient pollutants feed the growth of algae" causing dramatic fluctuations of dissolved oxygen, says Santucci. "This is not a habitat that river fish like."

The river redhorse (CW, Spring '04) is one such fish. Redhorse have disappeared from many heavily dammed sections of the Fox where sediment has clogged gravel beds. "These suckers reproduce somewhere in the Fox or its tributaries," Santucci says. "They run up creeks or they breed on gravel bars in the river where quickly flowing water keeps their eggs oxygenated." He adds that dam removal will also help expand habitat for many invertebrate species, including mayflies and water-cleaning filter feeders such as mussels, which have suffered drastic reductions over the last century.

David Horn, president of the group Friends of the Fox River, says that other animals also could return to the river. While it would be "hard to quantify in terms of 'x-number more Acadian flycatchers along the banks of the Fox,'" he says, "there's no reason to expect anything other than that the removal of the dam will improve habitat for flora and fauna and the organisms that depend on them." He adds that dam removal also could improve community drinking-water quality and lower filtration costs.

The Community Perspective
Many Batavians like the North Dam because the current configuration is pleasant to the eyes and ears, as well as a good resource for boaters and fishermen. In fact, a citizen group called Save the Dam won a non-binding referendum drive to keep the dam. One of the group's organizers, 50-year Batavia resident Ruth Johnson, wishes city officials had followed the example of downstream Yorkville. There, a citizen petition drive led elected officials to back a $6.2 million IDNR plan to modify its Glen Palmer dam. Ten percent of the river's water will flow through a 1,000-foot-long channel designed to allow the passage of fish as well as canoeists and kayakers.

Batavia City Manager Bill McGrath claims the referendum was misleading. Politically, he says, "It would have been a lot easier for us to go the Yorkville way." Yet he contends that the Yorkville project's cost exceeds the benefits. "The jury's out on whether these fish ladders work. And what's the point of spending all these millions if you're not going to deal with all the sedimentation upstream?"

Openlands Project's Ders Anderson says the key to support for healthy rivers is to start educating people early on about the streams in their own neighborhoods. Without public awareness, he says, "the value judgment from the citizenry and their locally elected officials sways towards the aesthetic view that they would rather not change. Understanding the dynamics of the river and what it needs to be healthy is not something that takes hold in the 12 to 18 months of debate when the issue formally arises."

David Horn says that people will care more when they experience a wild river system for themselves. "Whether it's a canoe trip, a walk along the Fox River Path, or wading into a local stream and turning over rocks, you're going to see a great diversity of plant and animal life that lives around or within the river."

Public education efforts are being undertaken by such groups as the Fox River Ecosystem Partnership, Friends of the Fox River, Batavians for a Healthy River, Prairie Rivers, Illinois Sierra Club, Friends of the Chicago River, The Conservation Foundation, many forest preserve districts, and, of course, the IDNR. With more than 120 mainstream and tributary dams in the Chicago region, the river-reconnection crowd will be paying close attention to the example Batavia sets.

Batavia's Post-Dam Look
State-contracted engineers are finalizing designs for the river's new configuration. The waterline just above the dam, they estimate, will drop about seven feet after removal. The water itself will be about a foot shallower, and engineers will redistribute up to six feet of accumulated sediment, some to build islands and streambanks. McGrath anticipates that once the dam is gone, the river could be about one-third of its current width for a half-mile upstream of the dam site. Floodplain vegetation will be planted on dewatered portions, creating a natural buffer zone that will filter runoff and provide some streamside wetland habitat.

When the Fox River breached the South Batavia Dam in late 2002, the impoundment narrowed upstream (left, June 2003). By September 2003 (right), vegetation had returned to the riverbanks. Photos by Steven Scheffel.

Strollers on the Riverwalk won't hear a local version of Niagara Falls anymore, but they will be able to see the bottom of the river. Meanwhile, boulders will amplify the sound of rushing water. "We're going to lose the water -skiing, and the current may be a bit too fast for families who like canoeing on the impoundment," McGrath says. "But there's going to be a lot more sport fishing." And once the North and South Batavia dams are gone, canoeists will be able to cruise continuously for six miles from Geneva to North Aurora.

Victor Santucci's findings have made him an advocate for dam removal. He has presented his study in dozens of forums with hopes of "getting the science out there. A lot of people say they don't care about the fish," he says, "but almost everybody cares about clean water."

Downtown Batavia will have a different look. But Bill McGrath expects positive reactions from anyone visiting the Riverwalk for the first time. "They won't know what was here before. What they come and see will be the Fox River."