Pacific Northwest Cooperative Ecosystem Studies Unit (CESU)

Willow Creek Reservoir Water Quality Research and Evaluation Studies

Project ID: W912HZ-26-2-A035

Federal Agency: U.S. Army Corps of Engineers

Partner Institution: Portland State University

Fiscal Year: 2026

Initial Funding: $92,596

Total Funding: $92,596

Principal Investigator: Wells, Scott

Agreement Technical Representative: Bellringer, Holly

Abstract:

Willow Creek Reservoir, near Heppner, Oregon, is located at river mile 52.4 on Willow Creek, a 

tributary of the Columbia River at river mile 250. The dam was completed in 1983 as a multi-purpose flood control project with other project purposes including recreation, irrigation, water supply, water quality and fish and wildlife habitat.

The goal of the current study sponsored by the Corps of Engineers (2026) is to improve the water 

quality of Willow Creek Lake with a focus on cyanobacteria, dissolved oxygen and nutrients. Also, the National Resources Conservation Service (NRCS) within the USDA has goals of improving Willow Creek water quality “by reducing the amount of irrigation runoff and 

erosion/sedimentation that leaves the [agricultural] area” and makes its way to Willow Creek Lake 

The four study pillars from the Corps (2026) that are discussed in the current proposal include the following elements:

  • Empirical data acquisition and evaluation
  • Water quality and hydrodynamic model set-up and evaluation
  • Evaluation of mitigation scenarios with field data and the model
  • Dissemination of results to the community and in published research