Modifications to CE-Qual-W2 Model

WEST Consultants, Inc. was tasked by the Portland District, U.S. Army Corps of Engineers to investigate impacts to downstream temperatures due to releases from nine reservoirs in the middle reaches of the Willamette River. As part of the study WEST modified Version 3.7 (beta) of CE-QUAL-W2 to allow for several methods to blend the withdrawals from a reservoir to meet downstream in-stream temperature targets for fish habitat. The study included estimating the change is temperatures released from Hills Creek reservoir, and influenced by tributaries, as inflows temperatures to Lookout Point Reservoir. In addition, we evaluated a number of blending strategies including (1) blending from two existing outlets, (2) release from a single elevation of a multi-port tower, and (3) blending releases from two elevations of a multi-port tower.