Skip to main content
U.S. flag

An official website of the United States government

Modeling water quality effects of structural and operational changes to Scoggins Dam and Henry Hagg Lake, Oregon

June 9, 2006

To meet water quality targets and the municipal and industrial water needs of a growing population in the Tualatin River Basin in northwestern Oregon, an expansion of Henry Hagg Lake is under consideration. Hagg Lake is the basin's primary storage reservoir and provides water during western Oregon's typically dry summers. Potential modifications include raising the dam height by 6.1 meters (20 feet), 7.6 meters (25 feet), or 12.2 meters (40 feet); installing additional outlets (possibly including a selective withdrawal tower); and adding additional inflows to provide greater reliability of filling the enlarged reservoir. One method of providing additional inflows is to route water from the upper Tualatin River through a tunnel and into Sain Creek, a tributary to the lake. Another option is to pump water from the Tualatin River (downstream of the lake) uphill and into the reservoir during the winter--the 'pump-back' option. A calibrated CE-QUAL-W2 model of Henry Hagg Lake's hydrodynamics, temperature, and water quality was used to examine the effect of these proposed changes on water quality in the lake and downstream. Most model scenarios were run with the calibrated model for 2002, a typical water year; a few scenarios were run for 2001, a drought year. More...

Citation Information

Publication Year 2006
Title Modeling water quality effects of structural and operational changes to Scoggins Dam and Henry Hagg Lake, Oregon
DOI 10.3133/sir20065060
Authors Annett B. Sullivan, Stewart A. Rounds
Publication Type Report
Publication Subtype USGS Numbered Series
Series Title Scientific Investigations Report
Series Number 2006-5060
Index ID sir20065060
Record Source USGS Publications Warehouse
USGS Organization Oregon Water Science Center