State and Federal Studies Conclude that Sediment is non-toxic

Studies analyzing the chemical make-up of reservoir sediments have concluded that the sediment poses no risk to human health.[1],[2],[3],[4],[5]   

Opponents to river restoration often cite the Camp, Dresser , and McKee Study which speculates that the high cost of sediment removal will push dam removal into the billions of dollars. However, this report fails to acknowledge the results of the studies referenced above, of of which were peformed after the Camp et al. report was published.

State and Federal Studies Conclude that Sediment pollution will be short lived

Key Findings of the Sediment Transport Studies performed by Federal Agencies include:

  • Dam removal could mobilize between one-third and two-thirds of the 13.1 million cubic yards of sediment trapped behind the dams currently stored within the reservoirs and transport it downstream to the Pacific Ocean. The majority of the material behind the dams is fine grained and would not be deposited in the river channel or estuary, it would float out to sea.
  • Sediment transport modeling indicates that high concentrations of suspended sediments would occur immediately downstream of Iron Gate Dam for two-to-three months following reservoir draw down as we prepare to remove the dams.
  • Sediment concentrations could result in lethal and sub lethal effects on some of the coho salmon smolts and steelhead in the river. However, coho salmon, steelhead, and other fish populations would quickly return to 2012 population numbers, and increase in abundance and viability after dam removal.
  • The plan for reservoir drawdown in a winter of a single year (2020) is designed to minimize negative effects on sensitive fish species, particularly federally listed coho salmon.


Klamath Dams do not serve Flood Control Function

A common myth perpetuated by dam removal opponents is that if the dams are removed, downstream communities will be subject to catastrophic flooding. In reality, implementation of the Klamath Agreements will add to the Basin's water storgage capacity. The Agreements call for removal of the lower four dams which cumulatively have 11,749 acre feet of active storage capacity. However, the Agreements also require expanding the active storage capacity of Upper Klamath Lake by 97,000 acre feet - a net gain of 85,251 acre feet of water storage.



[1] Klamath River Dam and Sediment Investigation,California Coastal Conservancy, November 2006.

[2] Preliminary Review of 2006 Analytical Testing Data from Sediment Sampling Conducted at Iron Gate, Copco 1, and JC Boyle Reservoirs, in Klamath River, Oregon and California,California Coastal Conservancy, September 22, 2006

[3] Klamath River Reservoirs - Preliminary Sediment Sampling Data and Background Info, United States Depart of Interior, October 2010.

[5]Draft Environmental Impact Statement for Hydropower License for Klamath Hydroelectric Project, September 25, 2006.