The project is located at the confluence of Gales and Roderick Creeks. Historically, the confluence of Roderick and Gales Creek was characterized by a mosaic of primary and secondary channels with extensive off-channel wetlands. The project successfully restored some of these historic functions on a 20 acre parcel by realigning Roderick Creek, which was in a straightened ditch, greatly expanding floodplain, and restored off-channel wetlands that are hydrologically connected to Roderick Creek and its floodplain during high flow events. The site was revegetated with native species, creating a mosaic of riparian, wetland, prairie, and upland habitats. In addition, a partial fish passage barrier at Half Mile Lane was replaced with a free-span bridge.
Half Mile Lane Mitigation Bank
Client: Clean Water Services (CWS), Oregon Department of State Lands (DSL)
Waterways assisted Clean Water Services and Department of State Lands in the planning and design of a 20 acre mitigation bank in the Tualatin River Watershed to provide wetland, temperature, and salmon credits. In addition to providing purchasable credits, the project simultaneously tested a function-based accounting system developed by the Willamette Partnership’s Counting on the Environment program (http://www.willamettepartnership.org). This program was developed with the help of public, private, and non-profit stakeholders to create a shared accounting system for quantifying impacts and benefits to ecosystem services for application to ecosystem markets. The Partnership has completed a test version for water temperature, wetlands, salmonid habitat, and upland prairie that was applied to pilot projects. Half Mile Lane was one of the pilot projects that tested three of these services, and was the first pilot site that resulted in real-world transactions. The project tested not only the ecosystem credit calculator, but also the sequence of developing, selling and buying ecosystem credits.