After almost completely drying out this summer, water has begun to return to the 140-acre Oaks Bottom Wildlife Refuge in southeast Portland, as work wraps up on an extensive wetlands rehabilitation project.
Oaks Bottom is the largest remaining natural area within the lower Willamette River flood plain, with meadows, woodlands, and about 75 acres of wetlands, directly adjacent to the Willamette River. It is home to bats, beaver, otter, mink, reptiles, amphibians, coyote, deer, and about 100 species of birds. However, until this summer its only direct connection to the Willamette River was a small culvert which, along with an old water control feature, combined to essentially choke off the fresh water inflow from the river – to the detriment of migrating salmon. That is all changing now.
The Oaks Bottom Wildlife Refuge Habitat Enhancement Project is an $8.8 million tidal wetlands restoration project, and it's nearly complete. The small culvert and water control structure have been removed and a very large new open bottom arch culvert has been installed. As the Willamette River rises this fall, this open connection between the river and the wetlands will allow free-flowing water to enter approximately 2,000 linear feet of new channels to flood the wetlands, providing a refuge for migrating juvenile salmon from the open river, while also enhancing the habitat for its many other wildlife species. The project also includes removal of invasive plants, planting of new native species, and a new wildlife viewing platform along the popular Springwater Corridor.
The lead funder for the $8.8 million budget is the Army Corps of Engineers, with the City of Portland contributing 35%. The general contractor is LKE Corporation of Washougal, a woman-owned business that has worked in land restoration and rehabilitation since 1993. LKE utilized GPS-controlled excavating and contouring machines for the project, following a computer-aided design prepared by another woman-owned business, Westlake Consultants of Tigard.
This wildlife habitat enhancement project both rehabilitates an important natural wetlands environment and provides practical benefits like flood control and natural filters to keep the Willamette clean. These benefits further enhance Portland's reputation as a desirable place to live, work, and invest. The project is on schedule and bicycle commuters will be pleased to know that the Springwater Corridor will be back open shortly. Migrating juvenile salmon should also be pleased with their enhanced habitat.
