CORVALLIS, Ore. — With a pair of long-handled loppers in hand, Jona Engel waded into a willow thicket just south of the Benton County Fairgrounds on a late morning last week and started snipping 2-foot cuttings off branches.
"You want ones that are going to survive," Engel said. "Good green leaves, nice and straight."
Engel, a 23-year-old senior in mechanical engineering at Oregon State University, was one of six students in Steve Cook's Geosciences 300 class, Sustainability for the Common Good, who spent several hours Nov. 5 grubbing out weeds and planting willow cuttings on the site of a former lumber mill.
The students get course credit, and Benton County gets free labor for an 18-acre wetland restoration project on the site.
"This is the third time we've done this in cooperation with this course instructor," said Adam Stebbins, a project coordinator for the county.
The county also has used work crews from the jail and the juvenile corrections program to help keep costs down on the project, which began in 2009.
The early phases of the restoration focused on taking out levees and accumulated woody material from the old mill's log pond, reconstructing the channel of Dunawi Creek through the property, and uprooting invasive plants such as reed canary grass and Scotch broom.
"We had to dig down close to eight feet to remove all the reed canary and all the chipped wood," Stebbins said.
After that, the focus shifted to regenerating native vegetation. In addition to seeding the area with a variety of grasses, work crews have planted close to 10,000 shrubs and trees, from willow and cottonwood to swamp rose and Pacific ninebark.
The project is intended to meet state and federal requirements to mitigate the environmental impacts of a street realignment and some redevelopment work undertaken by the property's owner, Andrew Martin.
Benton County Public Works Director Roger Irvin said the wetland reconstruction to date has cost about $250,000, with the county and Martin splitting the bill. The cost of monitoring and maintaining the restoration work over the next five years or so, which will be considerably less, will be absorbed by the county, Irvin said.
Under a conservation easement negotiated between Martin and the county, the project area is to be maintained as a natural wetland.
In the meantime, the former mill site is already beginning to look more like a natural area than an industrial zone.