Great Miami and Whitewater Basin Modeling Study
Ohio and Indiana
In order to provide information on the benefits of their projects, the Louisville District Corps of Engineers is required to compare the flood elevations that have occurred with projects in place (modified conditions) with what would have occurred under natural conditions. The District uses a combination of the PRECIP, HEC-1, and HEC-5 models to produce the data required for this comparison. The District contracted with Skees Engineering and FTN to develop the required models, and prepare the comparison data for the Great Miami and Whitewater River Basins for 15 historical events.
Based on a basin map prepared by Skees Engineering showing basin outlines and locations of precipitation and flow gages and ArcInfo GIS developed basin centroids, FTN developed a PRECIP model to produce 3-hour basin-average precipitation using data from the District's DCPs, the National Weather Service, and NCDC.
Using the basin-average precipitation data and available observed flow data, HEC-1 models were developed and calibrated (Snyder parameters, loss rates, and base flow parameters) for 7 headwater gages for 3 storm events each to within 10% of the observed peak and within 3 hours of the observed time of peak.
Using the calibrated models, total basin HEC-1 models were developed and calibrated for both the Great Miami and Whitewater Basins for 15 events each. Regional correlation of hydrologic parameters was used for the ungaged basins modeled.
HEC-2 was used to develop a rating curve for an ungaged control point to provide the data necessary to compare modified vs natural condition water surface elevations.
HEC-5 models were prepared for each system based on the District lakes and their physical characteristics and operating criteria: CJ Brown Lake in the Great Miami River Basin and Brookville Lake in the Whitewater River Basin. The HEC-5 model for each lake was then applied to the 15 events calibrated earlier with HEC-1.
Comparisons were made to observed data and modified vs natural condition water surface elevations.
Little Rock, AR
● Fayetteville, AR
● Baton Rouge, LA
● Jackson, MS
