Illinois Environmental Protection Agency Charleston Side Channel Reservoir TMDL
Table 8. Comparison of Measured and Simulated Monthly Average Flows.
Simulation Name: Upper Embarras Simulation Period:
Watershed Area (ac): 599,188
Period for Flow Analysis
Begin Date: 10-01-72 10-01-72 Baseflow PERCENTILE: 2.5
End Date: 09-30-82 09-30-82 Usually 1%-5%
Total Simulated In-stream Flow: 121.56 Total Observed In-stream Flow: 110.96
Total of highest 10% flows: 60.56 Total of Observed highest 10% flows: 54.70
Total of lowest 50% flows: 8.96 Total of Observed Lowest 50% flows: 8.04
Simulated Summer Flow Volume (Months 7-9): 18.12 Observed Summer Flow Volume (Months 7-9): 14.48
Simulated Fall Flow Volume (Months 10-12): 26.56 Observed Fall Flow Volume (Months 10-12): 16.47
Simulated Winter Flow Volume (Months 1-3): 44.31 Observed Winter Flow Volume (Months 1-3): 44.63
Simulated Spring Flow Volume (Months 4-6): 32.57 Observed Spring Flow Volume (Months 4-6): 35.38
Total Simulated Storm Volume: 119.85 Total Observed Storm Volume: 109.76
Simulated Summer Storm Volume (Months 7-9): 17.71 Observed Summer Storm Volume (Months 7-9): 14.19
Errors (Simulated-Observed) Recommended Criteria** Last run
Error in total volume: 8.72 10
Error in 50% lowest flows: 10.29 10
Error in 10% highest flows: 9.69 15
Seasonal volume error - Summer: 20.09 30
Seasonal volume error - Fall: 37.98 30
Seasonal volume error - Winter: -0.71 30
Seasonal volume error - Spring: -8.65 30
Error in storm volumes: 8.42 20
Error in summer storm volumes: 19.86 50
* Months 1–3 = January, February, March
Months 4–6 = April, May, June
Months 7–9 = July, August, September
Months 10–12 = October, November, December
** Source: Lumb, et al., 1994.
SWAT2000 Modeling Appendix B-17
