2026 C.shasta and Klamath Water Temps

Klamath Irrigation District · Setting the Record Straight

The Facts on Spring Flows and Young Salmon

Each spring, we hear that large river releases are needed to protect juvenile salmon from disease. This year's monitoring tells a more specific story. The chart below puts three things on one timeline: when the wild young Chinook leave the river, how warm the water gets, and how the C. shasta infection rate climbs.

What the data shows

Ceratonova shasta (C. shasta) is real, and we take it seriously. It is also seasonal — it tracks water temperature. This year the first detection came on April 2, and the infection rate in the weekly samples then climbed steeply, reaching roughly 90–100% by late April as the river warmed.

By then, most of the wild run was already gone. Across all the reporting juvenile traps — Shasta, Scott, Bogus, Fall, Shovel, Jenny, and the ODFW Spencer and Klamath stations — about 580,000 natural-origin young Chinook were counted this season, and an estimated 80% had emigrated before that first April 2 detection, while the water was still cold.

In plain terms: the bulk of the wild outmigration moved through cold water, ahead of the disease-and-temperature spike. We do not pretend the cost was zero — coupling the catch to the measured infection rate puts an estimated 13% of the run (about 75,000 fish) as infected, mostly in the warm-water tail. But the largest spring flow demands arrive after most of the fish they are meant to protect have already passed the upper river.

Regulated for one fish — while the water follows another

Here is the part worth sitting with. The flows that limit water to Klamath Project farms are required under the federal Endangered Species Act to protect coho salmon, which are listed as threatened. Coho are the listed species — they are the legal reason the river is given priority over the headgate in a dry year like 2026, when stored Upper Klamath Lake water is released to hold river flows above what the season would naturally provide.

But the fish in this chart are Chinook — and Klamath Chinook are not listed under the federal Endangered Species Act, fall run or spring run. They are the fish that fill the juvenile trap counts, and they are the fish at the center of the disease monitoring used to argue for higher spring flows.

There is one more link in that chain. Klamath Chinook still enter the federal picture — not on their own, but as food. Reclamation's own 2024 Biological Assessment defines an action area that reaches out into the Pacific Ocean, where, in its words, the Southern Resident Killer Whale — an endangered population of orcas — “feed on concentrations of adult Chinook Salmon.” Chinook are the orca's primary prey. So the unlisted Klamath Chinook are folded into the federal consultation indirectly: as ocean prey for a listed animal that lives hundreds of miles away. Whether that distant link should drive how a dry-year river is rationed at the headgate is a fair thing to put on the table.

So the record raises a fair question: Klamath farmers are being curtailed for a listed species (coho), while the disease case used to argue for higher spring flows is built largely around an unlisted one (Chinook). And when the bulk of those Chinook have already passed in cold water — as the chart shows — it is fair to ask how the late-spring flows line up with the fish they are meant to protect, and which fish those are.

A closer look: where the 2026 water came from

This second chart uses Reclamation's own daily accounting. The blue line is the natural water arriving at Upper Klamath Lake (net inflow, with the A Canal already subtracted); the orange line is the flow released downriver at Keno to meet the federal target; the gold line is the lake's surface elevation. Through the winter and the cold-water outmigration — when the young Chinook were actually leaving — inflow ran well ahead of the release, and the lake filled more than three feet, peaking on April 5. Only after that, as natural inflow fell away, did the release begin to outrun it: on 42 of the 60 days after the April 5 peak, the prescribed Keno flow exceeded what nature delivered to the lake that day, so the river was held up by drawing stored water back out. In plain terms, the stored water that sustains the prescribed flow is spent mostly in May and June — after the fish have gone.

We support healthy fish runs. We also believe water decisions affecting hundreds of farm families should rest on measured timing and real numbers. The cold-water window is when these fish actually move — and that is where management should follow the science.