North Coast Land Conservancy has completed the first phase in an ongoing project to decommission roads in the Rainforest Reserve to help rewild the landscape and prevent erosion that can have detrimental impacts on the watershed.
As a former timber farm, the Rainforest Reserve included roughly 16 miles of logging roads when NCLC acquired it in 2021. An ecological assessment of those roads found that without intervention, the roads and associated culverts posed a significant risk to fish and amphibian habitat, as well as community drinking water sources below.
As a result, a broadscale roads assessment was completed as part of management planning for the reserve. The goal was to determine the least amount of road milage necessary for NCLC to access various parts of the Rainforest Reserve to carry out long-term stewardship, identifying which roads are necessary and which pose the greatest risk.
For several decades, it’s been known that deteriorating roads in the mountains can have a negative impact, particularly if they cross a stream or river.
“You bring crushed gravel and put millions of pounds of it on the mountainside,” NCLC Stewardship Manager Colin Meston explains. “It causes this ongoing erosion.”
A landslide can cause sediment and debris to fall into the water, creating downstream problems throughout the watershed. Meanwhile, maintaining a road along a steep mountain, which involves replacing culverts, is costly.
Once the roads assessment was completed, the first phase of decommissioning began last fall in partnership with the Oregon Department of Forestry (ODF) and Arch Cape Community Forest staff.
Emulating the Mountainside
There are several different approaches that can be used for this process. NCLC elected to remove the culverts and then unpack the road materials and recontour them to mimic the natural angles of the mountain slopes.
“When you don’t have that shelf, it’s less likely it would erode,” Colin says.
The team also has replanted diverse species of trees, shrubs and wildflowers to stabilize the new bank.
Not all the roads needed to be decommissioned. The focus is on those that pose a threat of mass failure, where road debris like gravel, logs, silt and mud slide into streams, suffocating salmon and amphibian habitat, as well as having a detrimental impact on drinking water filtration.
Responding to an Emergency Landslide
In January, the importance of this project came into focus, as a landslide further up in the Rainforest Reserve required 200 dump-truck loads of debris to be removed and a temporary culvert to be placed. Fortunately, the team got to the landslide prior to another big rain, which could have propelled tons of debris into the West Fork of Ecola Creek.
“Landslides in the mountains are natural, but this one landed on one of our roads and could have caused ecological harm if we hadn’t worked quickly to clean it up,” Stewardship Director Melissa Reich says.
Currently, NCLC has finished decommissioning about 2 miles of roads above Arch Cape Creek, funded by a grant from the Oregon Watershed Enhancement Board (OWEB). Now, the organization is seeking funding and planning for decommissioning about 4 miles of roads in the Ecola Bowl, past where the landslide occurred, which would be phase two of the project.
“Once we remove those 4 miles of road, landslides will continue to happen in the future, but they will deliver gravels and wood and good habitat to our streams, rather than road fill and human-caused sediment delivery that can be harmful to habitat and drinking water,” Melissa says. Phase three will likely include about 2 miles along Onion Peak Road. However, the team continues to evaluate the plan, determining the most important roads to decommission to restore the landscape to its healthy ecological function, while protecting the drinking watershed for the communities, Colin says.
Comments