Which of the following is considered a structural BMP?

Retention basins are classified as structural Best Management Practices (BMPs) because they involve physical structures designed to manage stormwater runoff. These basins temporarily hold stormwater to allow sedimentation, which helps reduce pollution entering local waterways. By detaining stormwater, retention basins also help manage the rate and volume of runoff, minimizing flooding and erosion downstream.

In contrast, employee education programs, community awareness campaigns, and regulatory guidelines focus on behaviors, outreach, and policies rather than physical infrastructure. While they are essential aspects of a comprehensive stormwater management strategy, they do not fit into the category of structural BMPs, which specifically refers to the physical installations used to control and treat stormwater.