LWI Region 3 Modeling Overview

Gage Analysis and Results HEC-SSP v2.3 was used for Bulletin 17C flood frequency analysis with model-derived (rating curve) peak flows. Deer Park (1990–2023) and Wild Cow Upper (Open Gate, 2003–2023) were analyzed. A Log-Pearson Type III distribution with station skew was applied due to local influences. April 2021 served as a perception threshold. Wild Cow Upper showed higher peaks in comparison to Deer Park, consistent with its larger drainage area (Figure 4-23).

LEARN MORE: (C_APPENDIX A-4)

Figure 4-21: Best fit rating curve for the Wild Cow Upper gage under Open Gate conditions.

Figure 4-22: Comparison of rating curve predicted flow and model flow hydrograph at Wild Cow Upper under Open Gate conditions. (September 2020 event)

Figure 4-23: Flow frequency plot for Deer Park.

51

Precipitation and Frequency Analysis and Consequence Modeling