Studies recently presented by the Comparative Survival Study group suggest an alternative to removing dams for helping spawning salmon in the Columbia River system, which includes not only the Columbia River but also the massive Snake River. The study suggests that increasing the amount of water that comes over the top of the dam—not through the turbines—will be benefit populations.
Oftentimes juvenile salmon returning to the ocean are sucked into the deep reservoirs above dams and then through the turbines. Increasing the spill-over would divert these salmon from the turbines so they can safely return to the ocean, the study suggests. Scientists say that there are non-biological benefits as well: the dam and the cheaper power they provide would still be available, the jobs dams provide would be preserved, the recreational opportunities made available by the reservoirs would be not be hindered, and the plan would not affect irrigation usage.
However, the plan is not without its critics. Opponents point to the above-average salmon returns seen in recent years and the cost of allowing water to spill over the dam rather than go through the turbines. Proponents suggest that factors uncontrollable by humans have caused the greater than average salmon season and that the cost will still be less than removing the dams and other options.