Buttress Dam: Leave It Alone!
You've decided that the electric power this dam provides is more important than the population of salmon in the river. You're not alone. Large dams all over the world, like the Grand Coulee Dam in Washington, have endangered salmon populations. But these dams also provide a significant chunk of electric power to millions of people.
Many businesses that rely on this dam's electric power will be happy with your decision. But environmentalists and sports fishermen will be very upset.
This is a difficult decision, because there really is no perfect answer. See what would happen if you made a different choice.