Projects & Programs
East Bank Fireboat Dock Project—Willamette River 100-Year Flood Analysis, Oregon
The construction of the Eastbank Fireboat Dock on the Willamette River, Oregon requires a hydraulic modeling analysis as part of the "No-Rise" certification to demonstrate that construction will not cause the 100-year flood water surface elevations to rise. PNNL staff were contracted by the Portland Development Commission in collaboration with KPFF Consulting and Engineers to conduct this study. The model selected for this evaluation was the U.S. Army Corps of Engineers' river analysis model, HEC-RAS.
Using the data available, a HEC-RAS model of the Willamette River extending from its mouth at the Columbia River up to the Willamette Falls at river mile 26.4 (RM 26.4) was developed. River cross-section data, including modifications for bridges, were incorporated into the model. The model runs were conducted using the Willamette River 100-year flood flow of 375,000 cubic feet per second. Following calibration, the model was applied to simulate project conditions with the presence of the Eastbank Fireboat Dock. The predicted 100-year profile for the project conditions was compared with the 100-year flood profile corresponding to existing conditions. Based on the model results, there is no predicted rise in the water surface elevation as a result of reduction in cross sectional area due to the Eastbank Fireboat Dock. In the worst-scenario simulation, the model prediction showed a maximum water surface increase of 0.03 feet in the upstream cross section of the proposed Eastbank Fireboat Dock, which is still negligible.
Project Highlights:
- Developed a HEC-RAS model of the Willamette River, extending from its mouth at the Columbia River up to the Willamette Falls at RM 26.4
- Predicted 100-year water surface elevation profile for the project compared with the 100-year flood profile of existing conditions and determined no significant impacts as a result of the Eastbank Fireboat Dock project.