Mississippi River Priority Site

Mackinaw River, Illinois

The Mackinaw River watershed, which covers more than 740,000 acres in central Illinois, contains some of the United States' most productive farmlands. More than 75 percent of the watershed is used for agricultural purposes, and crops such as corn and soybeans are key to the area's economy.

At the same time, the watershed provides habitat for 66 fish species, 31 mussels including the at-risk slippershell, nine species of crayfish and 264 of the 299 birds that regularly occur in Illinois, including nesting sites for four at-risk avian species. Other at-risk species found in the area include three plants, an amphibian and two reptiles.

Although urban expansion and changing agricultural practices have resulted in some habitat loss and declines in water quality, the Mackinaw River basin nonetheless remains a prime example of a restorable watershed. And, for more than 15 years, The Nature Conservancy has been working to accomplish that task.

Strategies and Progress

In 1991, the Conservancy began discussing with a number of partners strategies for protecting and restoring the Mackinaw. The Conservancy then led a successful effort that gained in 1996 official state designation for the Mackinaw Ecosystems Partnership, through which the Conservancy works side by side with farmers, other conservation groups and government agencies. The partnership has led to many projects undertaken as part of the Mackinaw River Watershed Plan, a blueprint for protecting the area's ecological integrity.

Conservancy efforts within the Mackinaw watershed have included a seven-year paired watershed study that revealed that focused outreach efforts—informative meetings and agricultural demonstrations—can persuade farmers to use conservation-oriented agricultural practices such as grassed waterways, stream buffers and conservation tillage. Recent efforts include measuring the effectiveness of constructed wetlands at improving water quality not only locally but throughout the entire watershed.

The Conservancy also has signed a 10-year cooperative agreement with the Franklin family to turn 250 acres of their farm into a place where farmers and others can learn firsthand about cutting-edge agricultural methods that benefit nature.

At this site, the Conservancy and partners are measuring how large wetlands need to be in order to effectively reduce nutrients from agricultural runoff. Because the Conservancy believes it is important to balance the economic needs of farmers with ecology, the effects on farm income of implementing such methods will be carefully evaluated.

The Conservancy's pursuit in central Illinois of solid scientific evidence to identify economically sound farm practices that also benefit plants and animals in agricultural watersheds is now an integral part of the Mississippi River program. Word of ecological successes along the Mackinaw can be transmitted readily to other agricultural watersheds within the Mississippi basin, thus improving water quality and wild habitats throughout the Midwest.

The work along the Mackinaw River is important locally and on a much wider scale. Lessons learned within the watershed will be shared through the Conservancy's Great Rivers Partnership to advance the Conservancy's national and global efforts to protect the Earth's critically important freshwater resources.


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