Development of a Water Quality Model of the Sammamish River

A laterally-averaged, vertically 2-dimensional water quality model of the Sammamish River was developed using the CE-QUAL-W2 (Version 3.2) model developed by the U.S. Army Corps of Engineers Waterways Experiment Station (ACOE-WES). The model was developed to allow for simulation of the effectiveness of possible future river restoration scenarios, including but not limited to riparian restoration and increased groundwater inflow. These restoration approaches have been considered due to the high water temperatures routinely observed during summer low-flow conditions in the river.

The development (including minor code modifications), calibration, and testing of the Sammamish River model is described in this report. The current version of the model is most capable of simulating water temperatures, except in the lower portion of the river influenced by the backwater from Lake Washington based on comparison to temperature data collected between 1998 and 2003. Primarily due to the difficulty of capturing the dynamics of aquatic plant growth in the river, the model does not perform as well for other water quality constituents of interest – particularly dissolved oxygen.

Download the Report

This report is provided in Adobe PDF format. You will need Adobe Acrobat to view the document. For help using Acrobat files, please visit our Acrobat© help page.

Download the Sammamish River Water Quality Modeling Report