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Lecture XIII.

Hydroelectric Power - The Risks:
The Salmon Problem:

Extremely Emotional Issue --> icon of the PNW
Some Federal Dam Licenses can now be lost because of salmon migration problems

Some studies suggest Federal dams are mostly resonsible for drop from 16 million to 300,000 wild fish per year
Actual Salmon Count data is available for these dam sites:

John Day Dam
Bonneville Dam
Lower Monumental Dam
McNary Dam
The Dalles
Ice Harbor Dam
Lower Granite Dam
Little Goose Dam

Estimated that to improve migration, utility rates will rise in the PNW by 8%
There are lots of other factors at work as well:

El Nino
Agressive Fishing
Poor logging practices and increased soil erosion

Note that reservoirs offer expanded habitat for geese, pelicans, eagles, osprey. They also help with flood control thus minimizing soil erosion in the watershed.

Adverse effects of dams on salmon:

migratory barrier
killed in turbines (especially young ones swimming downstream)
supersaturation of air in water (high pressure of water falling down forces air into the solution)
reduced oxygen content if river flow is reduced (summer) due to separation of warm and cold water; cold water doesn't mix to be aerated (this is mostly a problem in the Tennesee Valley)

Solutions:

Build fish "passages" to direct them towards tributaries --> this has proven successful for trout in Oregon
Better turbine design and screen systems can help eliminate fishkill on the downstream migration
Minimize turbulence in the operation of the turbine
Have better flow control

How will potential lost power be compenstated for?

energy conservation?
sale of hydro to the US by Canada?
Coal-fired plants?
Read More About it (note: this document will take a few minutes to load)
The Columbia River Salmon Passage model (CRiSP)
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