Hydrologic And Hydraulic Analyses Of Silver Creek And Selected Tributaries Associated With Scott Air Force Base, Illinois, 2022–24
Abstract
A hydrologic model of the Silver Creek Basin in southwest Illinois, and a hydraulic model of a selected reach of Silver Creek and local tributaries on and near Scott Air Force Base, Illinois, were developed to assess the effects of temporal land-use development in the Silver Creek Basin, the potential effects of projected changes based on future precipitation, and the effects of added detention storage in selected tributaries near Scott Air Force Base. The hydrologic model consists of a total of 52 scenarios—24 scenarios for an assessment of basin-wide changes in hydrology, and 28 scenarios for the hydraulic analysis of a focus area of Silver Creek and tributaries on and near Scott Air Force Base. Scenarios were run for precipitation events of 2-year through 500-year recurrence intervals (50-percent through 0.2-percent annual exceedance probability) and 24-hour durations.
The effects of detention structures added to Silver Creek tributaries throughout Scott Air Force Base were greater on water-level profiles (about 1 to 3 feet) than the effects of projected (2050) changes in precipitation (about 1 foot or less) in these basins. The results indicated that despite the increases in water-surface elevations resulting from projected increases in precipitation, the detention structures could provide a net reduction in water-surface elevations in the flood-prone western tributaries on the base. The effects of detention structures and projected precipitation also were assessed using the mapped extent of inundation for the simulated probabilistic precipitation scenarios. As an example, limited inundation of a residential area along Ash Creek was evident in the 5-year recurrence interval event for the scenarios without detention storage, whereas the first indications of flooding in the residential area from the scenario with detention storage were in the 50-year recurrence interval event.
Changes in hydrologic conditions followed a spatial pattern similar to that of the changes in land-cover development, with the greatest changes in the downstream one-half of the Silver Creek Basin and most pronounced in subbasins on and surrounding Scott Air Force Base. There was up to an estimated 54.6-percent increase in peak streamflows in subbasins on or near Scott Air Force Base from historical (1992) to current (2019) conditions, but changes in peak streamflows of as much as 144 percent are anticipated under the planned (to about 2050) land cover plus projected (2050) precipitation. The changes in the timing of peak streamflows were towards earlier peaks, with cumulative changes between historical and projected conditions approaching 0.75 hour (45 minutes) for a 2-year recurrence interval event. Results of the percentage change in cumulative event volume were similar to those of percentage change in peak streamflows in terms of magnitude of change and temporal and spatial distribution of changes. The greatest magnitude of percentage change in the assessed hydrologic properties was associated with the 2-year recurrence interval event, and the magnitude of the percentage change decreased with increasing probabilistic event recurrence interval. Subbasins with a substantial change in runoff yield between historical and current conditions were primarily in the downstream one-half of the Silver Creek Basin and most were within or adjacent to Scott Air Force Base. The magnitude of runoff yield changes increased with recurrence interval, and maximum changes were associated with subbasins on base and with the changes between the historical and current conditions.
Recommended Citation
C. V. Cigrand et al., "Hydrologic And Hydraulic Analyses Of Silver Creek And Selected Tributaries Associated With Scott Air Force Base, Illinois, 2022–24," USGS Scientific Investigations Report 2024-5117, vol. 2024, U.S. Geological Survey, Jan 2024.
The definitive version is available at https://doi.org/10.3133/sir20245117
Department(s)
Geosciences and Geological and Petroleum Engineering
Publication Status
Open Access
International Standard Serial Number (ISSN)
2328-0328; 2328-031X
Document Type
Article - Journal
Document Version
Citation
File Type
text
Language(s)
English
Rights
© 2026 U.S. Geological Survey, All rights reserved.
Publication Date
01 Jan 2024
Comments
Although this report is in the public domain, permission must be secured from the individual copyright owners to reproduce any copyrighted materials contained within this report.
Prepared in cooperation with Scott Air Force Base.
Recommended Citation: Cigrand, C.V., Heimann, D.C., and Rydlund, P.H., Jr., 2024, Hydrologic and hydraulic analyses of Silver Creek and selected tributaries associated with Scott Air Force Base, Illinois, 2022–24: U.S. Geological Survey Scientific Investigations Report 2024–5117, 87 p., https://doi.org/ 10.3133/ sir20245117.
Associated data for this publication: Cigrand, C.V., and Heimann, D.C., 2024, Archive of hydrologic and hydraulic models used in the analyses of Silver Creek Basin and selected tributaries associated with Scott Air Force Base, Illinois, 1992–2050: U.S. Geological Survey data release, https://doi.org/ 10.5066/ P9GBYP2K.
U.S. Department of Agriculture, 2021, GeoSpatial data gateway: U.S. Department of Agriculture, Natural Resources Conservation Service, http s://dataga teway.nrcs .usda.gov/ GDGOrder.aspx.
U.S. Geological Survey, 2021, USGS water data for the Nation: U.S. Geological Survey National Water Information System database, https://doi.org/ 10.5066/ F7P55KJN.
Acknowledgements: The authors acknowledge Joseph Weber (Restoration Program Manager) and Graham Hults (Environmental Program Manager) from the Scott Air Force Base for their assistance in collecting information and resources on infrastructure, flooding, and planned development on and near Scott Air Force Base. The authors also acknowledge the Illinois Department of Natural Resources for their continued funding for the operation of the Silver Creek near Troy, Illinois, streamgage, and the U.S. Army Corps of Engineers—St. Louis District for their funding of the Silver Creek near Freeburg, Illinois, streamgage.
The authors also acknowledge U.S. Geological Survey employees Dan Grant, Aaron Walsh, and Josh Keele for field assistance in the installation, surveying, and operation of water-level monitoring equipment used in this study, and the collection of streamflow measurements used in model calibration.