Document Type

Technical Report

Publication Date



Willamette River (Or.) -- Water quality -- Models, Water-supply -- Models, Willamette River (Or.) -- Water quality -- Computer simulation, Hydrologic models, Hydrodynamics -- Mathematical models


Water Environment Services of Clackamas County is in the process of planning upgrades on several of its wastewater treatment plants (WWTPs) which discharge into the Lower Willamette River. The goals of the modeling effort were to:

• Gather data to construct a computer simulation model of the Lower Willamette River system in order to evaluate the impact of the WWTP discharges on water quality

• Ensure that the model accurately represents the system physics and chemistry (flow, temperature, dissolved oxygen and nutrient dynamics) by model calibration

• Use the model to evaluate how to meet various future discharge scenarios for Water Environment Services of Clackamas County.

This report evaluates the model calibration and discusses issues relative to that calibration effort. The calibration effort focused on model predictions of hydrodynamics (flow and water level), temperature, and eutrophication model parameters (such as nutrients, algae, dissolved oxygen, organic matter, coliform).


Technical Report EWR-2-01 produced by the School of Engineering and Applied Science, Department of Civil Engineering, Portland State University.

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