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Miles (1996) describes the Bluford-Ava-Hickory Association as being nearly level to very steep,
somewhat poorly drained, very slowly to moderately permeable soils. This association is on side
slopes along drainages and on broad ridge tops. It was originally deciduous forests. Slopes vary
widely, ranging from one to 45 percent. The Cisne-Hoyleton-Darmstadt Association is not
recognized as a distinct soil association by Miles (1996). This association is found in nearly level
to gently sloping, poorly drained areas. These are the prairie soils; they are found on broad till
plains, with slopes up to 7 percent.
Both of these soil associations are considered by Miles to be well suited or moderately well
suited to cultivated crops.
Climate
The climate in the East Fork Kaskaskia River watershed is temperate continental. The Midwest
Regional Climate Center (Champaign, Illinois) provided 30 years of historical precipitation data
for Station 114756 in Kinmundy, IL. Kinmundy averages 41.23 inches of precipitation each
year. The monthly average is 3.44 inches, and ranges from 2.09 inches in February to 4.19 inches
in July.
Hydrology
Streamflow data for watershed ILOK01 are available from a gage on the East Fork Kaskaskia
River near Sandoval, IL (05592900). The gage is located on the left (south) bank at U.S.
Highway 51, at river mile 9.9. The drainage area of this gage is reported by the USGS to be 113
square miles (72,320 acres). There are daily discharge records from October 1979 to date. From
these records, Harza Engineering Company calculated return periods for given floods (Table 5).
Table 5. Estimated discharges for select return periods at East Fork
Kaskaskia River near Sandoval, IL (Source: Harza, 2003)
Return Period (years) Discharge (cfs)
1 750
2 2,900
3 3,800
5 4,900
10 6,400
Figure 5 is a flow duration curve, indicating median flows around 8 ft3/s. According to Singh et
al. (1988) the 7-day, 10-year low flow is zero for this stream.
Electronic Documents of Illinois
