PacifiCorp Powerdale Dam Decommissioning and Removal

MB&G served as Environmental Manager for the decommissioning and removal of PacifiCorp’s 5-megawatt Powerdale Hydroelectric Project on Hood River in Hood River County, Oregon. MB&G prepared all permit applications for the project, including a Joint Permit Application (JPA) to the U.S. Army Corps and Oregon Department of State Lands in accordance with Section 404 of the federal Clean Water Act and Oregon Removal-Fill Law. Additional tasks included preparation of Threatened and Endangered Species Survey Plans; Re-Vegetation Plans to support JPA preparation and submittal; and development of permit applications in support of County permit requirements including the Columbia River Gorge National Scenic Area requirements.

MB&G also conducted a rare plant survey and was responsible for preparation of a project-specific Turbidity Management Plan to monitor and reduce construction-related impacts on turbidity during dam removal.

The environmental compliance phase of the project included Certified Erosion and Sediment control Lead (CESL) trained staff that visited the site on a weekly basis to ensure permit compliance. Monitoring frequency increased with the onset of in-water work. During this phase of the project, MB&G monitored in situ turbidity levels upstream and downstream of the project per requirements of the Turbidity Management Plan.