First Advisor

Scott Wells

Term of Graduation

Winter 2020

Date of Publication


Document Type


Degree Name

Master of Science (M.S.) in Civil & Environmental Engineering


Civil and Environmental Engineering




Hydrodynamics -- Mathematical models -- Case studies, Chehalis River (Wash.)



Physical Description

1 online resource (xiii, 174 pages)


The Chehalis River is located in southwest Washington State. Its headwaters are in the Willapa Hills, and it drains parts of the Doty Hills, the western foothills of the Cascade Mountains, and the southern Olympic Mountains. The Chehalis River is over 125 miles long and its basin is over 2000 square miles spanning parts of seven counties and diverse land uses.

CE-QUAL-W2 is a widely used two-dimensional (vertical and longitudinal) hydrodynamic and water quality model developed by the US Army Corp of Engineers and the Water Quality Research Group at Portland State University. Version 4.2 includes the ability to run waterbodies in sequence rather than simultaneously, which improves model run times.

This study expands and refines the work of Van Glubt et al. (2017). Model calibration was extended an additional year through 2015. Flow and temperature correlations used to fill model data gaps were updated with new data. 2018 dye study and periphyton data collected by the Washington State Department of Ecology were used to improve model calibration. Temperature and flow models of four large tributaries of the Chehalis River were created.

There remains room for improvement to the mainstem and tributary models. Better characterization of tributary water quality would improve the mainstem model's predictive ability. Model geometry in mainstem and tributary models could be further refined. Measurement of tributary flow rate and temperature at upstream boundaries would improve the utility of the tributary models.


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Persistent Identifier (692851 kB)
Chehalis River CE-QUAL-W2 model files (72580 kB)
Tributary CE-QUAL-W2 model files