A watershed average slope value is often needed in some hydrologic calculations, for example, Time of Concentration (TOC) estimation using NRCS Lag Time Method. The slope tool in AcrGIS or…
A watershed average slope value is often needed in some hydrologic calculations, for example, Time of Concentration (TOC) estimation using NRCS Lag Time Method. The slope tool in AcrGIS or…
Even if 2D modeling by XPSWMM, PCSWMM, HEC-RAS, and InfoWorks has become popular these days, 1D modeling still holds its ground on storm water management and flooding study due to…
Head Losses (or energy losses) associated with conduits in a storm sewer system include pipe friction losses and minor losses. Pipe friction losses are normally solved by Manning’s equation, while…
A DEM, before it can be used for watershed delineation, often needs to be reconditioned and pre-processed by “filling” any depressions or sinks (an area lower than its surroundings) to…
TauDEM, developed by Utah State University is a set of tools to extract and analyze hydrologic information from topography as represented by a DEM. TauDEM is a set of standalone command…
In HEC-RAS 2D, the terrain created from LiDAR DEM often does not have enough details for areas located within a river channel. For better modeling purpose, normally a river bathymetry…
A storm water pump station (Figure 1) is needed in low areas of a drainage system where drainage by gravity is not possible, such as a depressed roadway segment. Pump…
In hydrologic modeling, "nested" storm distributions are widely used such as SCS Type I, IA, II, III, or the frequency storm in HEC-HMS. One of the advantages of a "nested"…
A previous post introduced the design of a detention basin using Modified Rational Method in HydroCAD, and this post is about detention basin design using SCS hydrology in HydroCAD. The…
After a detention basin (a pond in HydoCAD) is added to the model and its storage is defined as explained in here, the next step is to model and design…