Problem Statement

Located near the Jefferson National Forest in Virginia, John's Creek is a mountain stream that is popular for recreation and kayaking. The stream also runs through New Castle, Virginia, a small rural town with a population of about 200 people (US Census, 2019). The location of the streamgage sits under a small bridge, where it has been determined that a large culvert should replace the current structure due to flooding concerns. You have been tasked by the Town of New Castle and Craig County to determine the necessary capacity of this new culvert by performing a flood frequency analysis. The resulting culvert should be able to carry the design flood safely while also remaining as economical as possible.

Module Overview

To design this new culvert, you will first need to understand the basics of probability theory and stochastic analysis in hydrology. Then the module will walk you through the steps of frequency analysis and how such an analysis can be helpful in water resources design and hydrologic studies. Finally, using USGS streamgage peak flow data from the John's Creek Streamgage location, you will perform a flood frequency analysis to choose a culvert design that can carry the required design flood and is both safe and economical for the town.