By Steve Guild, IRU Summer Intern
In southeastern Washington four dams on the lower Snake River have all but extirpated anadromous fish from the most prolific salmon fishery in the lower 48. Those dams still kill the majority of Idaho’s salmon and steelhead even though it’s clear their removal would restore the runs.
There are myths, however, that surround the removal of dams.
- Removing dams comes with excessive costs.
- There is difficulty replacing power when a dam is removed.
- All dams provide flood protection.
To understand the impacts dam removal and what it means for wild fish recovery there are excellent examples of contemporary dam removals that help debunk the myths.
For 98 years the 125-foot Condit Dam completely blocked fish from the upper sections of the White Salmon River and its tributaries. Construction of Condit Dam began in 1912 and when completed the 15MW of energy it produced was more then enough to power the paper mill which required only 3MW. Wooden fish ladders were included in the original dam construction but they failed by 1917 and were not replaced.
In 1996 Federal Energy Regulatory Commission (FERC) issued its final Environmental Impact Statement on Condit Dam. If the dam’s owner, PacifiCorp, wanted to continue running Condit Dam the company would be required to build permanent fish passage facilities. In 1997 PacifiCorp asked FERC reverse its decision to require fish passage in order to run the dam. FERC denied the request, and that forced PacifiCorp to take a harder look at the numbers. Simple economics motivated the company to remove Condit Dam, opening salmon spawning habitat that had been closed off since 1917.
“The cost of building the required fish passage facilities would have been $30 million. Therefore the relicensing of the dam was uneconomical,” write Michael C. Blumm and Andrew B. Erickson in an Environmental Law article titled, Dam Removal in the Pacific Northwest. “Instead PacifiCorp entered into a settlement agreement with several groups which capped the removal costs at $17.15 million. On October 26, 2011 Condit Dam was breached.” For just over half the projected cost of adding fish passages to the dam, Condit was removed.
This debunks myth one, the notion that dam removal comes with excessive costs. Moreover, the 15 megawatts of electricity the dam once produced was easily replaced by new and higher capacity generation equipment–myth two debunked as well.
While some dams in the Columbia Basin provide flood protection a vast majority were built for either transportation or electricity generation. Condit’s removal, in fact, alleviated flood risk by restoring a natural braided river system that gives direction to higher flows and mitigates flood risks naturally–myth three debunked.
Condit’s removal not only proved a common-sense measure that made economic sense, it made salmon recovery possible. Just one year after its removal salmon returned to the headwaters of the White Salmon River. The recovery was swift and unaided. In the first year, 85 percent of the fish upstream of the dam site were wild. Only two years after dam removal 93 percent of returning salmon fish were wild. If this type of fish recovery is possible after total extirpation imagine the impact removing the lower four Snake River dams could have for Idaho, where a small percentage of wild fish still make it home every year.
The natural flow of the Lower Snake River has been altered significantly by the four lower Snake River dams. Built to create an ocean port at the city of Lewiston, Idaho, the dams slowed the river and increased its depth for barge traffic. This comes with a number of negative effects.
Slowing the river causes water to warm more than it would in a natural flow regime. Warmer water has lower available oxygen content then cold water, and studies have shown that warm water also speeds the metabolism of returning fish. The combination of increased metabolic activity with lower available oxygen is often fatal for fish. For salmon returning to Idaho the maximum tolerable temperature is 68 degrees Fahrenheit. Fish that are able to make it back to their headwaters in spite of these odds have a lower fitness level, which means fewer and less productive salmon spawning nests, called redds.
Because the four lower Snake River dams are run-of-river dams they provide minimal power production but cost taxpayers millions of dollars every year. When asked how much power the dams produce, federal agencies offer their total nameplate potential, but for generators to produce at full capacity a deep reservoir and gravity-pressurized system would be required. These run-of-river dams do not provide the necessary conditions for power production–particularly in the summer and winter when flows are low and electricity demand is high.
The bottom line is that the net benefit of the dams is less than zero. According to IRU member and Kooskia, Idaho, resident Linwood Laughy, the 20-year cost of maintaining the shipping channel in the Lewiston area alone is just under $100 million. This does not include the $34 million the Bonneville Power Administration reports it spends on maintenance of the four dams every year.
Contrast this exorbitant expense with the potential of restored runs of wild salmon and steelhead. According to a 2005 study by Ben Johnson and Associates, removing the four lower Snake River dams and restoring salmon would generate a net income of $544 million dollars a year in sport fishing–most of it in rural Idaho towns like Riggins, Stanley and Salmon.
Condit shows it’s possible, and the numbers show it’s probable–not an issue of if, but when. Let’s hope Idaho’s endangered salmon and steelhead are still around when the four salmon-killing dams on the lower Snake River are removed.