Hydrologic and hydraulic model development for flood mitigation and routing method comparison in Soap Creek Watershed, Iowa

In 2008, the state of Iowa suffered a disastrous flood that caused extensive damage to homes, agricultural lands, commercial property, and public infrastructures. To reduce flood damage across Iowa, the U.S. Department of Housing and Urban Development (HUD) awarded funds to the Iowa Flood Center and IIHR-Hydroscience & Engineering at the University of Iowa to conduct the Iowa Watersheds Project. The Soap Creek Watershed was selected as one of the study areas because this region has suffered frequent severe floods over the past century and because local landowners have organized to construct over 130 flood detention ponds within it since 1985.

Although the detention pond is a widely accepted flood control practice, its effectiveness as a system to reduce the peak flow rate has rarely been investigated. One primary objective of this thesis is to evaluate the benefits that these detention basins could bring to the downstream areas of the Soap Creek Watershed. The thesis also provides an overview of the physical characteristics of the watershed, which can help local residents gain a better understanding of their living environment with respect to streams, soil type, land use, and so on. In order to achieve this goal, we developed a numerical model that can mimic the process by which rainfall is converted into runoff. In addition, we developed a different numerical model that simulates how water flows through the channel. The second objective of the model is to compare these two models with respect to technology.