The video discusses the demolition of the nearly 100-year-old Marmet Dam in Oregon. It highlights the challenges of not only demolishing the dam but also managing the 18 million tons of sediment accumulated behind it. The process involves careful planning, model testing, and real-world execution to ensure the safety of the surrounding environment, including a salmon crossing and a canal. After the dam is demolished, the focus shifts to removing sediment and restoring the river flow.

What is one of the main challenges in demolishing the Marmet Dam?

• Relocating nearby residents

• Building a new dam

• Finding a new location for the dam

• Dealing with the accumulated silt

Why is precise demolition necessary for the Marmet Dam?

• To protect the nearby forest

• To save construction costs

• To ensure the safety of the salmon crossing and canal

• To minimize noise pollution

What must be done to ensure the safety of the salmon during the demolition?

• Increase water flow

• Install protective barriers

• Build a new habitat

• Move them to a safe location

What happens immediately after the dam is demolished?

• The river is redirected

• A new dam is constructed

• The debris is cleared and the canal is closed

• The area is flooded

How much sediment is carried downstream after the river is allowed to flow freely?

• 110,000 tons

• 75,000 tons

• 50,000 tons

• 150,000 tons