Three Creeks Floodplain Enhancement Project

The Three Creeks stormwater facility is a large, regional complex of wetlands, uplands, and open space areas that provide flood water detention at the confluence of Mount Scott, Phillips, and Dean Creeks. The key project objective was to improve water quality by optimizing over-bank flood storage in the floodplain, reducing peak flow at the facility, and enhancing riparian and wetland habitat. Members of the public use the natural area for recreation; these users were a key part of discussions about future use and access plans. The project met requirements that enabled WES to obtain funding from the Oregon Department of Environmental Quality Clean Water State Revolving Fund loan.

The Parametrix team led system evaluation, permitting, and outreach services to optimize flood control, water quality, and habitat. Parametrix conducted workshops to help the WES team select preferred restoration alternatives using multi-objective decision analysis. The system evaluation included:

  • Selecting the most appropriate hydrologic data for evaluating performance and developing alternatives.
  • Evaluating stream hydraulics and stages corresponding to different flow control rates in Mt. Scott Creek downstream of the facility.
  • Preparing a hydraulic model of the facility and control structure.
  • Developing and assessing alternatives and optimizing the current facility operations.
  • Preparing solutions that can be supported by the public and users of the Three Creeks Natural Area.

Parametrix scientists conducted on-site assessments of natural resources and helped prepare the project for environmental permitting. Engineers are now drafting plans for the selected alternative.

Three Creeks Floodplain Enhancement Project


Clackamas County Water Environment Services

Oregon City, OR
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