Luckiamute Confluence Planning and Design

The Luckiamute Confluence property is nestled between two tracts of the Luckiamute Landing State Natural Area, five miles north of Albany, on Willamette River mile 110.5. Greenbelt Land Trust recently acquired this 106 acre property, which is a critical addition to an expansive network of protected lands. This complex establishes 1,300 acres of protected floodplain forest habitat. Additionally, it is positioned between the Willamette River (with 0.42 mi of frontage), the Luckiamute River, and just upstream of the Santiam. The confluence of these rivers make it one of the most significant sites for fish & wildlife in the mid-Willamette. The Willamette Planning Atlas highlights it as one of the best opportunities for restoration on the Willamette. Key features of this property are that half of the site is in the two-year flood zone and the potential for allowing lateral migration of the river. Few sites allow for such significant natural processes to occur. In order to facilitate greater river / floodplain connectivity, Greenbelt is partnering with River Design Group to develop a hydro restoration alternatives analysis with a 30% engineering design. This design requires extensive GIS and remote sensing analysis, field surveys, data processing, hydrology and hydrolic modeling. This will inform how best to improve overall habitat conditions for juvenile spring Chinook salmon and Steelhead. This project will also develop a revegetation plan for the 100 acres of agricultural land that will be retired and planted to a floodplain forest.

The two-year inundation map for this site indicates that at least 50% of this property routinely floods and provides crucial off-channel habitat for salmonids. A primary opportunity for this property is to allow the Willamette to continue its lateral migration in a section of river that has few societal constraints. Past land clearing activities have removed vast tracks of riparian forests and converted these lands to agriculture. While 100 acres of this property are still being farmed, the mid-19th century survey maps show this site was composed of complex braided channels, extensive riparian forests with intermixed wetlands, side channels, and sloughs. This proposal seeks to understand how we best go about restoring these habitats in a highly modified system.