Introduction to Culvert Design
A culvert is a closed conduit under a roadway or embankment used to maintain flow from a natural channel or […]
Hydraulics
Various types of drainage facilities are required to protect the highway against surface and subsurface water. Drainage facilities must be designed to convey the water across, along, or away from the highway in the most economical, efficient, and safe manner without damaging the highway or adjacent property. The purpose of this manual is to provide detailed information on the subjects of hydrologic and hydraulic analysis related to highway design. This manual should be used in conjunction with the Washington State Department of Transportation (WSDOT) Highway Runoff Manual and the WSDOT Design Manual, specifically Section 1210.
Examples of Hydrology
Compute the 25-year runoff for the Spokane watershed shown in Figure 2-3. Three types of flow conditions exist from the
Existing Hydrologic Studies
Existing hydrologic studies have been developed for many rivers in Washington State. FEMA has developed most of these reports. USACE
USGS Regression Equations
While measured flows provide the best data for design purposes, it is not practical to gage all rivers and streams
Published Flow Records
When available, published flow records provide the most accurate data for designing culverts and bridge openings. This is because the
Modeling Requirements
MGSFlood should be used once the PEO has selected the BMP(s) for the project site and has determined the input
Continuous-Simulation Hydrologic Model (Western Washington Only)
When designing stormwater facilities in western Washington, the PEO must use an Ecology-approved continuous-simulation hydrologic model to meet the requirements
Continuous-Simulation Hydrologic Model (Western Washington Only) Read Post »
Runoff Parameters
The SBUH Method requires input of parameters that describe physical drainage basin characteristics. These parameters provide the basis from which
Design Storm Hyetograph
The SBUH Method requires the input of a rainfall distribution or a design storm hyetograph. The design storm hyetograph is