The mud flows started because of an intense rain event in the footprint of the wildfire. One-to-three inches of rain fell on parts of the McKinney Fire on Tuesday, according to the Klamath National Forest, which resulted in debris flows on multiple drainages in the area.
“Is it going to kill fish all the way down the river? Is it going to be a localized effect? We were observing dead fish twenty miles or more downstream from where we think the mudslides entered into the river,” says Craig Tucker with the Karuk Tribe in Northern California.
A variety of fish species live in the Klamath River, including Chinook and coho salmon, suckers and lampray. The fall run of Chinook salmon are just beginning to enter the river system, Tucker says. Among the sensitive fish populations in the Klamath River, the Southern Oregon/Northern California Coast coho salmon are a threatened species under the Endangered Species Act.
Tucker says biologists are worried the ash and debris has affected dissolved oxygen and pH levels in the river.
“Every time there’s a high-severity burn event in one of these watersheds, it creates the possibility of debris flows and mudslides,” he says.
The tribe is currently trying to get biologists into the restricted burn zone to find out the extent of the fish kill.
In hopes of clearing out the debris, the tribe is considering requesting an extra release of water into the river from Upper Klamath Lake from federal water managers at the Bureau of Reclamation as well as PacificCorp, which manages the several dams on the river.
But, during another year of intense drought, quickly accessing extra water from an over-allocated system would likely be challenging.