What are acceptable methods to compare existing and proposed hydraulic conditions?
• The U.S. Army Corps of Engineers’ River Analysis System (HEC-RAS) is the preferred hydraulic model. It allows you to perform one-dimensional steady and unsteady flow river hydraulic computations. • The U.S. Army Corps of Engineers’ HEC-2 program can be used although is has been superseded by HEC-RAS. HEC-2 allows you to conduct a one-dimensional, steady flow water surface profiles analysis. • The Federal Highway Administration’s HY-8 program is also acceptable under certain conditions. This software optimizes the culvert size, shape and inlet configuration to minimize the culvert cost in highway drainage systems. It provides the headwater elevations for a range of flows through the culvert. It does not compute open channel water surface profiles. • Properly performed hand calculations are acceptable. 12.8 Where can I find a good reference to determine the Manning Coefficient’s (N-Value)? You can find very useful information including pictures, descriptions and values from the followi
