Development of a Hydrologic Modeling System for the Dry Valley Catchment

Abstract

The natural geology and topography of Putnam and surrounding counties have created a drainage system reliant on karst features such as sinkholes and caves. One limiting feature of such a system is the potential for greater flow demand than the capacity of these often-narrow swallets and cave openings, which can lead to increased flooding scenarios. Within Putnam County, the Dry Valley Watershed southeast of Cookeville, Tennessee, which spans roughly 7580 acres, experienced massive flash flooding due to this effect in July of 2015. The objective of this study is to explore the karst drainage flooding problem in the Dry Valley area and develop a HEC-HMS model to simulate the 10-year, 50-year, 100-year and 500-year floods for this region while also analyzing previous storm events. To achieve this objective, the project team collected survey and meteorological data and imported these data into the ArcGIS and HEC-HMS models to develop basin and meteorological models using Soil Conservation Service (SCS) Technical Release 55 (TR-55) methods in order to force HEC-HMS solutions for the various expected flood recurrence intervals. These solutions were used to estimate potential storm runoff hydrographs at points of interest within the study region, and potential engineering solutions were explored to aid in ameliorating the flooding situation within this watershed.