What does an online BMP capture in terms of runoff management?

An online Best Management Practice (BMP) is designed to manage runoff by capturing and treating water in real time as it flows into the system. This approach allows these BMPs to handle the entirety of the runoff generated from a specific area during a storm event. They actively manage and mitigate the effects of runoff by facilitating processes such as infiltration, detention, and treatment before the water is discharged into receiving bodies. The design and functionality of online BMPs aim to ensure that all runoff is captured and managed effectively to reduce sedimentation and to control pollution, which underscores why the response indicating that they capture all runoff is accurate. Understanding this concept is crucial for effective water resource management and for achieving sustainable development goals.