Published Flow Records
When available, published flow records provide the most accurate data for designing culverts and bridge openings. This is because the […]
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.
Mean Annual Runoff
Sometimes it is necessary to determine the mean annual flow or runoff for a given stream. When published flow records
General Hydrology
The Washington State Department of Transportation (WSDOT) Olympia Service Center (OSC) Hydraulics Branch uses several methods of determining runoff rates
Flood Reports
Flood reports have been developed for many rivers in Washington State. Most of these reports, and the ones that are
Drainage Basin
The size of the drainage basin is one of the most important parameters regardless of which method of hydrologic analysis