Dahl Beach Mitigation Project
Cascade supported the Port of Portland in the development of the Dahl Beach Mitigation Project to offset impacts stemming from an early action contamination clean up, related to the Portland Harbor Superfund. Impacts including capping sediments in shallow water habitat; Cascade identified a suitable mitigation area on park property, owned by the City of Gladstone. The project has met all permitting obligations and was released from the permit after its 5 year monitoring period.
The mitigation project restored natural riverbank conditions in two locations at the Clackamas and Willamette River confluence. The project removed a portion of a parking lot and a failed sheet pile bulkhead, graded riverbank topography, installed woody habitat structures, and established native vegetation.
Cascade supported the Port’s efforts to work with the City of Gladstone, local user-groups, and permitting agencies to complete the project within a limited timeline. The Dahl Beach project was constructed during summer 2016, and Cascade has worked with Mosaic Ecology to manage the site, which met its performance criteria during its 5 year monitoring and maintenance program.