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North Santiam and Santiam River Model --
Willamette River Water Temperature Investigation

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USGS personnel constructed, calibrated, and tested a model of flow and water temperature in the North Santiam and Santiam Rivers, Oregon. These rivers are major tributaries to the Willamette River, and have been listed as impaired by the Oregon Department of Environmental Quality (ODEQ) due to water temperatures that exceed the Oregon State water-quality standard. Under the Federal Clean Water Act, ODEQ is required to produce a water temperature Total Maximum Daily Load (TMDL) for these rivers as a plan for bringing these rivers into compliance with the water-temperature standard. Flow and water-temperature models of the Willamette River and its major tributaries had to be constructed to provide the necessary tools for the TMDL. The USGS assisted in the TMDL effort by providing bathymetric and travel time data, and by constructing, calibrating, and testing models of the North Santiam and Santiam Rivers.


The approach and scope of the overall TMDL efforts in the Willamette Basin have been documented by ODEQ (ODEQ, 2001a; ODEQ, 2001b). ODEQ and its technical partners analyzed the available numerical models that could be used to simulated flow and water temperature in Willamette Basin rivers. Previously, models of flow and water temperature had been developed for these rivers, but all suffered from the absence of one or more important capabilities. For example, a previous QUAL2E model of the main stem Willamette River was developed by Tetra Tech in the 1990s, and that model simulated flow and water temperature in addition to other parameters (Tetra Tech, 1993). Unfortunately, the QUAL2E model uses steady-state streamflow, which is a limitation for the purposes of this TMDL, and lacks any sort of sophisticated algorithm to account for the effects of topographic or vegetative shading. Similarly, a previous USGS flowrouting model (DAFLOW: Laenen and Risley, 1997) had been developed for rivers in the Willamette Basin, but that model is one-dimensional, which does not allow for an adequate representation of thermal stratification in the Newberg Pool section of the Willamette River (river mile [RM] 50-26.5).

ODEQ decided that the requirements for the temperature TMDL work, and any future modeling work for nutrients, algae, dissolved oxygen, and pH, were best met by developing new models for these rivers using the latest version of the CE-QUAL-W2 model (ODEQ, 2001a). CE-QUAL-W2, developed by the U.S. Army Corps of Engineers and by Portland State University, is a dynamic two-dimensional model that simulates flow, water temperature, and many other constituents related to eutrophication processes (Cole and Wells, 2000). It has been applied to more than 400 waterbodies around the world; it is a well tested and proven model with known capabilities. The USGS used a previous version of CE-QUAL-W2 for its studies on the Tualatin River (Rounds and others, 1999; Rounds and Wood, 2001).

In this investigation, USGS personnel constructed a flow and temperature model of the entire length of the Santiam River and of the North Santiam River from its mouth upstream to Big Cliff Dam (the reregulation dam downstream of Detroit Dam). The models were calibrated for periods in both 2001 and 2002, focusing on the period from spring through fall. Calibration and model use was enhanced through discussions with the members of the Willamette Basin Model Coordination Team, which consisted of scientists from USGS, ODEQ, Portland State University, and the U.S. Army Corps of Engineers, among others.

Flow and temperature data used for the model came from several sources. Most of the streamflow and boundary temperature data came from USGS gages. Point source data were obtained from the appropriate municipalities. Some additional water-temperature data were collected by consultants, municipalities, or industries, using ODEQ protocols. Meteorological data came from a variety of sources, such as the Bureau of Reclamation's AGRIMET stations and the University of Oregon's Solar Radiation Monitoring Laboratory. Riparian vegetation data were digitized from aerial photographs by ODEQ staff, using a variety of GIS and field verification protocols.

The final models were used to simulate both baseline and hypothetical scenarios to provide the quantification of heat loads necessary for the TMDL. Scenarios tested included a number of sensitivity tests, in which changes in stream temperature were quantified as the result of changes in streamflow, dam-release temperature, and riparian shading.


CE-QUAL-W2 is a laterally averaged, two-dimensional flow and water-quality model developed by the U.S. Army Corps of Engineers and Portland State University. The simulated dimensions are longitudinal (along the length axis of the waterbody) and vertical (from water surface to bed sediment). The model simulates flow, horizontal and vertical velocities, and water temperature. It also can simulate many water quality constituents, including dissolved and suspended solids, dissolved oxygen, phosphorus, ammonia, nitrate, dissolved and particulate organic matter, phytoplankton, pH, bicarbonate, carbonate, alkalinity, and bacteria. It has been applied to more than 400 lakes and reservoirs around the world. Since the release of version 3, the model can also be applied to sloping river channels as well as lakes and reservoirs.

The model documentation, source code, and example applications are all available from the CE-QUAL-W2 web site. The model is actively supported and is under active development.

Analysis and Results

The details of the North Santiam and Santiam River models have been documented in USGS Scientific Investigations Report 2004-5001:

Sullivan, A.B. and Rounds, S.A., 2004, Modeling streamflow and water temperature in the North Santiam and Santiam Rivers, Oregon: U.S. Geological Survey Scientific Investigations Report 2004-5001.
[Available online at]

The report describes the objectives and results of the modeling work, including a quantification of model performance, a discussion of those processes that influence temperature in these rivers, and the results of sensitivity tests and hypothetical scenarios run with the model.


The model code, program, and all data necessary to run it for the years 2001 and 2002 are available from the links below. The model was compiled to run on the Windows operating system, but can be compiled and run on any system that has a FORTRAN 95 compiler. Although CE-QUAL-W2 is available with a graphical user interface, the copy distributed in these packages is a generic version that does not include the interface. The generic version produces the same results, but simply provides less feedback to the model user during the run. The generic version of the model was used exclusively by USGS personnel in this investigation.

The USGS model was compiled from version 3.12 (dated 15-Aug-2003) of the CE-QUAL-W2 source code using the Compaq Visual Fortran compiler (version 6.6.A) with the following options:

  /fast /nodebug /real_size:64
In particular, the "/real_size:64" option was important in avoiding memory alignment problems.


o Download the model and the data to run it:
Calibrated model for 2001 [ZIP, 1,418 Kb]
Calibrated model for 2002 [ZIP, 1,498 Kb]
o Animations of calibrated model output:
2001 water temperature
2002 water temperature

As part of the temperature TMDL, models for the Willamette River and its other major tributaries were constructed by scientists at Portland State University (PSU) and ODEQ. These other models, including code and documentation, are available for download from PSU via


Cole, T.M. and Wells, S.A., 2000, CE-QUAL-W2: A two-dimensional, laterally averaged, hydrodynamic and water quality model, version 3.0,: U.S. Army Corps of Engineers Instruction Report EL-00-1 [variously paged].

Laenen, A. and Risley, J.C., 1997, Precipitation-runoff and streamflow-routing models for the Willamette River Basin, Oregon, U.S. Geological Survey Water-Resources Investigations Report 95-4284, 197 p.

Oregon Department of Environmental Quality, 2001a, Modeling options to address Willamette River temperature, aquatic growth, dissolved oxygen, and pH concerns [Online], URL:, Accessed November 15, 2001.

Oregon Department of Environmental Quality, 2001b, Willamette Basin TMDLs: Work plan for development of models to address Willamette River temperature, bacteria, algae, dissolved oxygen, and pH concerns [Online], URL:, Accessed November 15, 2001.

Rounds, S.A., Wood, T.M., and Lynch, D.D., 1999, Modeling discharge, temperature, and water quality in the Tualatin River, Oregon: U.S. Geological Survey Water-Supply Paper 2465-B, 121 p.

Rounds, S.A. and Wood, T.M., 2001, Modeling water quality in the Tualatin River, Oregon, 1991-1997: U.S. Geological Survey Water-Resources Investigations Report 01-4041, 53 p.

Tetra Tech, Inc., 1993, Willamette River Basin Water Quality Study: Willamette River dissolved oxygen modeling component report, Tetra Tech final report TC 8983-03, volume 1 [variously paged].

Home | Overview | Willamette bathymetric survey | Dye studies | Width survey | N. Santiam temperature model

Questions? Comments? For more information about this project, contact:

Stewart Rounds
U.S. Geological Survey
2130 SW 5th Avenue
Portland, OR 97201

Oregon Water Science Center Home page
Oregon Water Science Center Hydrologic Studies page

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