Month: April 2022

Bridge scour describes the process of flowing water eroding the streambed or bank near a bridge. It is important to consider bridge scour because it is the most common cause of bridge failures (FHWA, 2012). HEC-RAS uses the methodology outlined in the Federal Highway Administration’s Hydraulic Engineering Circular No. 18 (HEC-18) to estimate scour at … Read more

Introduction Engineers and scientists are using GIS tools to develop HEC-RAS models more and more. As a result, imported cross-sections may have more than 500 points (the limit per cross-section in HEC-RAS). In addition, interpolated cross-sections can easily contain more than 500 points if the bounding cross-sections have more than 255 points. Luckily, the HEC-RAS … Read more

One-dimensional (1D) hydraulic modeling is based on open channel flow principles and calculations. The physical properties of open channels can vary widely, especially in natural channels. For this reason, it is very important to ensure that the cross-sectional geometry in your HEC-RAS model represents reality as closely as possible. Therefore, it is essential that a … Read more

One of the most significant improvements to the United States Army Corps of Engineers River Analysis System (HEC-RAS) program is the addition of two-dimensional modeling functions. Many engineers are accustomed to preparing one-dimensional (1D) models. Therefore, 2D modeling can be a little daunting at first. However, 2D modeling is not any more difficult than 1D … Read more

Many people who use the HEC-RAS Controller to automate HEC-RAS write their code in the Microsoft Excel VBA environment. This is probably because Breaking the HEC-RAS Code, which is the book that outlines how to use the HEC-RAS Controller was written for VBA. However, there are many people who are seeking to use other programming … Read more

HEC-RAS allows users to model a variety of structures including bridges, culverts, inline structures, and lateral structures. The lateral structure element is typically used to model flow coming out of a river into a storage area. However, lateral structures can be used to model a variety of hydraulic structures such as morning glory spillways, berms, … Read more

When I am manipulating station-elevation data for HEC-RAS, I often do this in Microsoft Excel. However, it can be tedious to copy and paste data for each cross-section into the Geometric Data Editor. In order to solve this problem, I used the HEC-RAS Controller to write a macro in Excel that automatically creates an updated … Read more

I have been using HEC-RAS for many projects and at several companies. Throughout my experience as an HEC-RAS user, I have learned how to develop hydraulic models more accurately and efficiently. There are many things I know now that I wish I could tell my younger self when she was struggling through her first hydraulic … Read more

Water resources engineering can be considered a broad field as it involves aspects of the physical sciences, engineering, biology, ecology, and even the social sciences. In this article, I will be focusing on the hydrologic and hydraulic aspects of water resources engineering. Hydrology is the study of how water moves across the land. Hydraulics is … Read more