The dams are strictly hydroelectric (generating a combined 163 MW of power, which is considered relatively small) and do not provide water for irrigation. The lowest dam on the river (Iron Gate Dam) provides no passage for fish, thereby locking salmon and steelhead out of hundreds of miles of upstream habitat. The river supports coho, spring Chinook, fall Chinook and steelhead.
Historically, the Klamath supported a large spring Chinook run which — despite the installation of a hatchery when the lowermost dam (Iron Gate) was built in 1964 — did not rebound. It is estimated that the Klamath supported up to one million returning salmon each year prior to the dams. Today, with the assistance of the hatchery, it averages between 100,000 to 200,000 salmon.
Causes for decline:
In addition to the blocking of fish passage, upstream management of other dams — in the cold headwaters of the Klamath — have prioritized irrigation management over salmon management, which presents a particular problem in the Klamath River. While all salmon require cool/cold river water, in the Klamath there is a lethal parasite (called Ceratonova shasta) which thrives in warmer water temperatures, and which is lethal to juvenile salmon. In 2014 and 2015, when the Bureau of Reclamation held water behind their headwater dams on the Klamath for irrigation, the parasite population exploded in the low flow. It is estimated that 80-90% of juvenile Chinook were killed in those two years by the parasite. The Klamath tribes have been fighting in court (and winning) for improved dam management for salmon.
PacifiCorp has been operating the four lowermost dams on the Klamath for years under an expired hydroelectric license, which pre-dates modern environmental laws. The company has determined that the cost to renovate the dams with fish ladders is greater than participating in their removal.
In the original deal to remove the dams (which fell through):
PacifiCorp wanted to transfer its license and contribute $200 million to bow out of the removal project. An additional $250 million would have come from a voter-approved California water bond. But regulators would only agree to it if PacifiCorp remained a co-licensee, which PacifiCorp considered to be a non-starter.
In this new deal:
Oregon, California and PacifiCorp each pay one-third of the cost of removal. The project is on track to begin in 2022, with removal in 2023, and restoration work to follow beyond 2023.
This is a remarkable success story about people working in partnership to benefit salmon.