Garlic mustard. Japanese knotweed. False brome. These invasive weeds and dozens more spread fast in parks, trails, roadsides, streambanks and wetlands along the Clackamas River, crowding out native plants. They know no boundaries, taking root on public, private and tribal lands.
An initiative now in its third year aims to coordinate efforts between federal, state, regional, and local partners and private landowners in managing invasive species and preventing the introduction or spread of new species across the 600,700-acre Clackamas River Basin.
The Clackamas River Invasive Species Partnership, or CRISP, grew out of conversations between the nonprofit Clackamas River Basin Council, the Clackamas Soil and Water Conservation District and Metro in late 2015 and now includes 13 public and nonprofit partners.
“The Clackamas River Basin has many different agencies and nonprofits working on various environmental issues, but until CRISP, there was little coordination of their efforts in general and particularly around weed control,” said Peter Guillozet, a former Metro naturalresources scientist who helped spearhead the organization’s efforts. “You had one group spraying weeds over there, one group pulling weeds over there, one group worrying about weeds over there but not having any money to do anything, one group coordinating volunteers over there.”
The partnership brings everyone together to identify and prioritize the weed infestations that pose the greatest threat to the watershed and focus limited resources on where they would be most effective. Weeds are prioritized based on their potential impact, potential spread and feasibility of control, among other factors.
“There are some weeds we can’t control,” Guillozet said. “They’re too widespread already, too expensive or too difficult to control, so we try to focus on species that are just as bad but that we can control and contain.”
Partners say one of the biggest successes of the initiative has been the ability to improve coordination and address gaps in the inconsistent management of weeds across boundaries.
For example, Metro and Clackamas County actively manage weeds on their properties, but private landowners whose properties sit sandwiched between public lands might not have the knowledge or resources to control weeds on their property. Left unchecked, the weeds could spread and eventually reduce the value and productivity of both private and public lands, impair water quality and degrade natural areas important for fish and wildlife.
CRISP provides the Clackamas Soil and Water Conservation District and the Clackamas River Basin Council with additional support, resources and funding to work with private landowners to control the same weeds their public neighbors are tackling – ensuring that high-priority weeds are treated across the entire basin rather than in patches.
Metro and the conservation district worked together to inventory the invasive weeds on several islands in the river, said Lindsey Karr, a specialist at WeedWise, a conservation program of the district, who was hired as part of the partnership to carry out the CRISP management plan.
“They were covered in weeds and causing problems for everyone, but there were so many different ownerships,” Karr said. “Together, we figured out who was managing which island, where the gaps were, and now we’ve collectively been able to treat almost all of the islands.”
The work continues to pay off, and the partners are hopeful they’ll receive another round of funding from Portland General Electric. CRISP received a five-year, $431,250 grant from the Clackamas River Habitat Fund in 2016 to help start its efforts.
“It’s been night and day,” said Sam Leininger, WeedWise program manager for the Clackamas SWCD. “Before, you felt isolated, but now everyone is investing resources, we’re gaining some ground and filling in the gaps. Consistent management across the whole watershed benefits everyone.”
Learn about local invasive weeds and ways to get rid of them