Mainstem Molalla Large Wood Addition Fire Recovery

The Molalla River is the first major tributary of the Willamette River entering from the east side upstream of Willamette Falls. Located in Clackamas County, on the ancestral lands of the Confederated Tribes of the Grand Ronde, the Molalla River provides habitat for ESA-listed spring Chinook and winter steelhead, resident rainbow and cutthroat trout, as well as coho salmon.
The Molalla River watershed was burned by both the Beachie Creek and Riverside fires and are expected to increase summer temperatures and winter high flow events. High summer water temperatures and a lack of spawning habitat were already identified as limitations before the fires, particularly for spring Chinook and winter steelhead. The long-term effects of the fires are expected to exacerbate these pre-existing limiting conditions in the Molalla watershed.
The fires represent a unique opportunity to restore and improve spawning and rearing habitat in the Molalla Basin. We will install large wood structures to address the major factors limiting fish populations. Burned trees are available for use in the proposed projects, eliminating the need for their purchase and reducing restoration costs.
We will also excavate the side channel and plant the riparian area.Partners in this restoration plan include Fruit Growers Supply Company, and scientists from ODFW, BLM, Bair LLC, and Parr Excellence. The project team consists of experts in watershed restoration with experience designing site-specific large wood jams to create self-sustaining habitat function.

The salmonid species in the Molalla are not only anadromous, but also migrate within the watershed and use different habitats seasonally and at different life stages. The best spawning habitat is in the upper reaches of the river, but suitable gravel and spawning sites are limited.
Wildfires tend to increase catastrophic flow events during winter months due to reduced vegetation, washing out existing spawning gravel, worsening the shortage of appropriate spawning habitat. Incorporating engineered log jams will retain spawning gravel and create deep scour pools to hold spawning habitat long term.