New Studies Confirm Klamath Dam Removal Beneficial for Salmon and Water Quality, No Increased Flood Risk
Three reports examine sediment transport, fish, and water quality impactJanuary 27th, 2009
Steve Rothert, American Rivers, 530-478-5672
Craig Tucker, Karuk Tribe, 916-207-8294
Caitlin Jennings, American Rivers, 202-347-7550
Nevada City, CA- Three new reports funded by the California Coastal Conservancy show that removing four large dams on the Klamath River will cause relatively minor negative effects in the short-run, will not require sediment removal, and will provide great benefits for the long-term health of the river and its fish.
“These new studies add to the already impressive library of scientific and economic reports that show dam removal to be a safe, affordable, and effective way to restore struggling runs of salmon,” said Steve Rothert, Director of the California Field Office for American Rivers. These reports and many others can be found at www.americanrivers.org/klamath.
Dam removal advocates from Tribal, fishing, and conservation communities lauded the findings. “The data confirm what we have been arguing for years dam removal is the best option on the Klamath,” said Karuk Vice Chairman Leaf Hillman.
The Water Quality report shows that the removal of the dams would:
Eliminate or greatly reduce toxic blue green algae production.
Greatly alleviate releases of harmful nutrients from oxygen-starved reservoirs.
Significantly decrease summer and fall water temperatures, from 4-7Â_ø F.
Substantially increase dissolved oxygen levels.
Reduce dramatic fluctuations of pH levels.
Likely reduce levels of fish disease-causing parasites.
The Downstream Biological Impacts study concludes that although fish populations will suffer some negative impacts immediately following removal, this effect will be short lived. Specifically,
Impacts to fall Chinook will be short-term, and the population should fully recover to pre-removal levels within five years.
Spring-run Chinook should experience rapid recovery to pre-dam removal stock levels.
Coho salmon should experience only short-term effects and populations will recover fully.
Steelhead populations could be highly affected but should experience a strong recovery.
Pacific lamprey are expected to recover relatively quickly from impacts.
The Sediment Transport analysis concludes that:
Less than 1/3 of the sediment trapped by the dams will be transported downstream.
Nearly all of the sediment that is transported will travel directly to the ocean without being deposited in the river.
Flood risk will not be increased appreciably.
Sediment concentrations will likely be significant during the first winter after reservoir drawdown.
After years of negotiations, PacifiCorp recently announced that it will surrender the four dams on the Klamath to restore imperiled salmon and steelhead runs. Removal of the dams is part of a broader agreement to restore the river and revive the basin’s fishing, farming, and tribal communities through watershed scale restoration, a water sharing agreement between agriculture and fisheries interests, and affordable power for local communities.
When these dams come down it will be the biggest dam removal and river restoration effort the world has ever seen.
The Klamath, flowing through Oregon and California, was once the third most productive salmon fishery on the west coast. Removing the four dams and restoring the river will boost ailing salmon runs by reopening access to over 300 miles of habitat and eliminating water quality problems caused by the reservoirs.