it has blocked condensor tubes of power plants in Illinois and else- 

 where. In addition, it may possibly displace the native fingernail 

 clams . 



Recommendations 



Restore lakes 



Past surveys of fish populations in the Illinois River and the 

 present electrofishing survey demonstrate that the most fish and the 

 most desirable kinds of fish are generally produced in the reaches of 

 the river with the most lateral lakes and backwaters. Marshes, lakes, 

 and backwaters are essential for fish production in the Illinois River, 

 because they serve as fish nurseries. The lakes have been degraded by 

 sediment, and fish and wildlife production has declined. 



The Illinois Department of Conservation has taken two approaches to 

 restoration of lakes along the Illinois River. One approach is to keep 

 the Illinois River from entering and degrading the lakes, and to rely 

 on groundwater and rainfall to maintain the water level. This is the 

 approach that will be taken in Banner Marsh. The Department of 

 Conservation is currently purchasing the Banner Special Drainage and 

 Levee District (mile 138-145.5), a former strip mine on the flood plain 

 of the river. The Department plans to restore the natural lake and 

 marsh habitat within the Banner district. The existing high levees 

 which surround the district will be maintained in order to keep the 

 river out of the restored area. 



The other approach to lake restoration is exemplified by Rice Lake 

 (mile 133-137) and Stump Lake (approximately mile 5). The Department of 

 Conservation has been able to restore aquatic vegetation in these lakes 

 by pumping water out of the lakes or allowing them to dry out naturally 

 (Personal Communication, September 1973, Mr. Robert L. Glesenkamp, Area 

 Wildlife Manager, Illinois Department of Conservation, Havana, Illinois). 

 Midsummer drying was a natural occurrence in this type of shallow lake, 

 during low-flow years, prior to Lake Michigan diversion and construction 



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