What distinguishes the second line of defense in erosion and sediment control?

The second line of defense in erosion and sediment control typically includes practices and measures that are implemented to address runoff and sediment that may have bypassed the first line of defense. This phase often incorporates structural controls, such as check dams, sediment traps, or detention basins, which are designed to manage and treat water that may be carrying sediment.

The key aspect that distinguishes this second line is that it usually requires maintenance to ensure it functions effectively over time. Maintenance may include tasks like removing accumulated sediment, repairing any structural damage, and ensuring that vegetation or other protective measures remain intact. This ongoing upkeep is essential to prevent failures that could lead to increased erosion or sediment transport, thereby undermining the overall objectives of erosion and sediment control efforts.

While the first line of defense is primarily focused on prevention—such as minimizing soil disturbance through vegetation or the installation of erosion control blankets—the second line is reactive, seeking to capture and mitigate the impacts of what has already occurred. Understanding this distinction underscores the importance of both lines in a comprehensive erosion and sediment control strategy.