Document Type

Technical Report

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Spokane River (Idaho and Wash.) -- Water quality -- Models, Water-supply -- Models, Spokane River (Idaho and Wash.) -- Water quality -- Computer simulation, Hydrologic models, Hydrodynamics -- Mathematical models


The Washington Department of Ecology is interested in a water quality model for the Upper Spokane River system for use in developing Total Maximum Daily Loads (TMDLs). The goals of this modeling effort are to:

• Gather data to construct a computer simulation model of the Spokane River system including Long Lake Reservoir and the pools behind Nine Mile dam, Upper Falls dam and Upriver dam for 2001 based on the calibration conducted for 1991 and 2000 data sets, (Annear et al, 2001).

• Ensure that the model accurately represents the system hydrodynamics and water quality (flow, temperature, dissolved oxygen and nutrient dynamics) for the three simulation years

A hydrodynamic and water quality model, CE-QUAL-W2 Version 3 (Wells, 1997), is being applied to model the Spokane River system. CE-QUAL-W2 is a two dimensional (longitudinal-vertical), laterally averaged, hydrodynamic and water quality model that has been under development by the Corps of Engineers Waterways Experiment Station (Cole and Wells, 2000).

In order to model the system, the following data were required:

• Spokane River flow, water level and water quality data at the upstream system boundary (the State of Idaho boundary)

• Tributary inflows and water quality

• Meteorological conditions

• Bathymetry of the Spokane River, the dam pools along the river, and Long Lake Reservoir

• Point source (wastewater treatment plants, WWTPs) inflows and water quality characteristics

Data have been primarily collected from 1991 to 1992, during 2000, and more recently during 2001. This report summarizes the 2001 data used in the modeling effort to expand the model calibration period.


Technical Report EWR-04-02 is a production of the College of Engineering and Computer Science Department of Civil Engineering, Portland State University and U.S. Army Corps of Engineers Waterways Experiment Station.

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