By Dr. Betsy Herbert
Betsy Herbert completed her Ph.D. at UC Santa Cruz in environmental studies in 2004. Her area of expertise is forest management for drinking water protection.
If you live in Corvallis, you may not know that the Rock Creek Watershed, just east of Marys Peak supplies about one-third of the city’s drinking water. The heavily forested, 10,000 acre Rock Creek Watershed is owned partly by the city and partly by the Siuslaw National Forest. Both the city and the Forest Service acquired these properties with public funding for the purpose of protecting the drinking water for the city of Corvallis. Instead, they’ve focused on logging, raking in the big bucks since 1955. In the process, they seem to have forgotten all about protecting the water supply . . .
Courtesy DoctorZa
The Good ‘Ole Days
Since the 1950s, both the city and the Forest Service clearcut immense stands of old-growth in the Rock Creek watershed, despite public protest. The city used logging revenue to reduce water user rates, to build pipelines and to update its water treatment plant. After logging was shut down in the early 1990s—to protect the spotted owl and marbled murrelet—the city and the Forest Service had to take a breather from logging for about 15 years.
In 2006, new federal logging regulations allowed some logging around endangered species habitat, so the city and Forest Service started up their revenue-driven logging once again.
Let the Greenwashing Begin
In 2010 the Forest Service authorized a massive 1,394-acre 12-year commercial thinning project throughout the city’s water supply area, eventually hauling out some 3,000 truck loads of logs. The logging plan claimed that the project was designed to improve forest structure and water quality. Trouble is, they logged right around the creeks that supply drinking water to Corvallis.
Meanwhile, the city of Corvallis engaged Trout Mountain Forestry to create a management plan for their ownership, entitled “The Corvallis Forest Stewardship Plan.” It’s actually a timber management plan, designed to greenwash the city’s logging as “improving forest health.” But read the fine print and you’ll find that timber revenues “may also be used to fund City water infrastructure expenses,” motivating the city to continue its exploitative logging.
In 2021, a new task force was appointed to oversee the Corvallis Forest Stewardship Plan update. Frank Davis, the retired Forest Service planner who designed the 12-year logging project in the city’s drinking water supply area serves on the task force.
What are They Trying to Hide?
Public works staff repeatedly claims that the water from creeks supplying the city’s drinking water is generally very clean, with naturally higher turbidity occurring in the rainy season and lower turbidity in the dry season. (Turbidity measures the clarity of the water, with higher turbidity indicating dirtier water).
But this explanation left a major question unanswered: Is turbidity increasing over time?
To answer that question, I obtained the turbidity readings taken at the treatment plant from 2008 through the present. The file contained some 1.6 million turbidity readings. A colleague, Dr. Karl Young, a data scientist, volunteered to analyze the data as a community service.
In January 2024, I submitted Dr. Young’s completed analysis to the task force. The report reveals that the turbidity of water entering the water treatment plant from the three creeks supplying the city’s water has increased over time. It’s increased so much that the water treatment plant has to be frequently shut down, in order to avoid damaging its filtration system. Two of the creeks are barely used at all. You can read the complete report here.
What Could be Causing This Increase in Turbidity?
In the Rock Creek Watershed, logging is the only human activity identified by the Oregon Department of Environmental Quality (DEQ) as a potential high risk to the drinking water source. DEQ identifies the entire area supplying drinking water as “high erosion potential.” Logging roads are known primary threats to water quality in drinking watersheds. The road network in the Rock Creek Watershed is dense enough to threaten both aquatic species and drinking water, according to National Marine Fisheries Service and DEQ. Read more about road density here.
Action Opportunties:
1) Attend the Corvallis Forest Stewardship Plan Task Force meeting on Wednesday, February 28 from 5 - 7 pm at the Madison Avenue Meeting Room, 500 SW Madison Ave. (across from City Hall). 10 days in advance you can register here to attend on line or to speak. If registration is not available, send an email to the task force at RCWTF@corvallisoregon.gov.
Please speak up and urge the city to protect its drinking water by reducing road density throughout the Rock Creek Watershed.
2) Check the Friends of the Corvallis Watershed website for more information.
3) Get involved with the ecosystem protection work of the Oregon Chapter Forest Team by contacting Carol at illinoisvalley@oregon.sierraclub.org.