Which description about armored spillways is correct?

Which description about armored spillways is correct?

• A. To dissipate energy at the outlet to minimize scour.
• B. To safely convey excess stormwater flow while preventing erosion.
• C. To filter sediments from runoff before it reaches the downstream channel.
• D. To store stormwater for drought conditions.

Answer: (B)

Armored spillways are designed to handle excess stormwater by providing a stable path for high flows while protecting the channel and downstream from erosion. The armor—typically rock riprap or reinforced concrete—reduces the erosive force of fast-moving water, distributes energy, and prevents scour along the spillway surface and in the downstream reach. This ensures safe conveyance of large flows without damaging the structure or surrounding ground. Filtering sediments isn’t the primary purpose here; that's the job of separate sediment control measures. Storing water for drought conditions isn’t what an armored spillway does either—storage is handled by detention facilities. While energy dissipation can occur at the outlet as part of managing high flows, the main function of armored spillways is to convey excess flow safely while minimizing erosion.

Armored spillways are designed to handle excess stormwater by providing a stable path for high flows while protecting the channel and downstream from erosion. The armor—typically rock riprap or reinforced concrete—reduces the erosive force of fast-moving water, distributes energy, and prevents scour along the spillway surface and in the downstream reach. This ensures safe conveyance of large flows without damaging the structure or surrounding ground. Filtering sediments isn’t the primary purpose here; that's the job of separate sediment control measures. Storing water for drought conditions isn’t what an armored spillway does either—storage is handled by detention facilities. While energy dissipation can occur at the outlet as part of managing high flows, the main function of armored spillways is to convey excess flow safely while minimizing erosion.