LAKE MANAGEMENT REPORTS 



2. FORK LAKE NEAR MOUNT ZION, ILLINOIS 



David H. Thompson and George W. Bennett 

 Illinois Natural History Survey 



Fork Lake was built In 1920 by Mr. Paul S. Smith for waterfowl, hook-and-llne 

 fishing and other recreational uses. Since Its establishment, the lake has been used 

 by large numbers of waterfowl during their spring and fall migrations. As many as 

 25,000 ducks have visited this pond during the course of a season. 



Soon after the lake was made. It was stocked with fish and for a few years 

 furnished excellent catches of bass and other "fine" fish. Later, In spite of heavy 

 stocking, hook-and-llne fishing became very poor. During the past year or two the 

 lake appeared to be crowded with small black bullheads. Golden shiners and small 

 sunflsh were also known to be present. Occasional evidence was seen of large "rough" 

 fish which would not take the hook. 



We recommended that all of these fish be removed and the lake restocked with, 

 largemouth bass and bluegllls. Since the lake could not be drained readily, the 

 fish were poisoned, June, 1938, A complete census of the fish present was made at this 

 time. This census Is especially significant because, very few fish having been 

 removed In recent years. It shows the carrying capacity of such waters for fish. 



After the fish were removed the water became clear. Within two weeks the lake was 

 restocked with largemouth bass fry and adult bluegllls. The bluegllls spawned through- 

 out the summer and their fry have been an Important food for the bass. These bass have 

 grown very rapidly and some of them should reach legal length by the time they are a 

 year old, 



ACKNOWLEDGMENTS 



Mr. Smith furnished a great deal of the Information. In this report and, together 

 with Mr. Sam A. Parr of the Conservation Department and Dr. Donald F. Hansen of the 

 Natural History Survey, helped In all stages of the work. When the census was made, 

 we were assisted by a number of people from the Department of Zoology of the University 

 of Illinois. Mr. Louis A. Krumholz of the Survey made the map. The view of the lake Is 

 from a photograph by Mr. James S. Ayars, editor for the Survey. The duck pictures were 

 taken from a blind by Mr. Smith a number of years ago, 



DESCRIPTION OF THE LAKE 



Fork Lake was formed by throwing an earthen dam across a ravine. It Is fed by 

 surface drainage from about 60 acres, part farmland and part timber. The soil Is a 

 tight, light-colored clay loam. 



In June, 1938, at the time the accompanying map was made, the water surface of the 

 lake was 5 Inches below the crest of the splllv/ay. The water area at that time was 1,38 

 acres. The maximum depth was 9 feet. The average depth was 5,7 feet, and the capacity 

 7.9 acre feet. According to Mr. Smith, there Is now about 4 feet of silt In the lower 

 end of the lake. 



The dam Is 120 feet long. The spillway Is 12 feet wide and 20 feet long. The 

 water descends In four steps, the highest of which Is 3 feet. The height of these 

 steps Is of some Interest since It seems likely that, during freshets, carp and buffalo 

 may have ascended the stream and Jvimped the spillway Into the lake. The lake has not 

 suffered extreme shrinkage during drought years. During the drought of 1930, the water 

 level fell about 3i feet below the crest of the spillway. 



