Klamath Water Users Association 

Fact Sheet

 

 


MYTH VS. FACT: 2002 Klamath River Fish Die-Off

Arguments made by environmental advocates and tribal biologists are lacking because they do not articulate how increased releases from Iron Gate Dam could have prevented the fish die-off more than 170 river miles downstream of the dam. If the primary cause of the fish die-off was warm water, it was physically impossible for Iron Gate Dam to cool the river down to tolerable levels for salmon.

MYTH: Biologists for the Karuk and Yurok Tribes have stated that water temperatures at Iron Gate Dam were 6 degrees cooler than water temperatures in the vicinity of the fish die-off more than 170 miles downstream of Iron Gate Dam. They suggest, but do not describe how, increased Iron Gate Dam releases in the upper river could have ameliorated water temperatures in the lower river.

FACT: Maximum water temperatures in the upper Klamath River were much higher than the lower river just prior to the fish die-off and very similar during the time of the fish die-off.

MYTH: Increasing upper Klamath reservoir releases during late summer or early fall during naturally dry hydrologic conditions, such as occurred in September 2002, would benefit salmon.

FACT: Because of a variety of meteorological, physical, and biological reasons, artificially increasing flows at that time would probably be harmful. This is due to the fact that Iron Gate Dam discharges are too warm for salmon during much of September.

MYTH: Additional Klamath Project flows released from Iron Gate Dam in early September 2002 would have prevented the fish die-off.

FACT: There is no evidence that releasing more water from Iron Gate Dam during early or mid-September could have prevented a fish die-off more than 170 river miles downstream because upper main stem temperatures were within the range known to cause mortality or reproductive failure in salmon. The gradual declining temperatures in the Klamath River downstream of Iron Gate Dam during the fall are primarily attributable to normal seasonal declines in ambient air temperatures, not river flow.

MYTH: 2002 was unique because there was a large salmon run and low Iron Gate Dam flows, which explains the fish die-off in September 2002.

FACT: Contrary to this claim, 1988 had a much larger salmon run than 2002 and the lower Klamath River flows were similar to that observed in 2002. According to the CDFG fish die-off report, in 1988 the lower Klamath River flow during September was 2,130 cfs, the salmon run was 215,322 fish and there was no consequent fish die-off; in 2002, the lower Klamath River flow during September was 2,129 cfs and the salmon run was 132,600 fish. These facts provide empirical evidence that this assumption is invalid.

Klamath Water Users Association
2455 Patterson Street, Suite 3
Klamath Falls, Oregon 97603
(541)-883-6100 FAX (541)-883-8893 kwua@cdsnet.net

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