There are several spots along the stream where branches collect, creating a natural dam. Water collects and filters through the branches, and when the water is high, over the top. It stops the dirt, pebbles and sediment from flowing downstream and causing erosion or buildup where it isn’t wanted.
There are places in business where natural dams are helpful too. A lot of stuff can flow around a business that isn’t helpful. Creating places where it can be caught and stopped from moving forward, while allowing for the things that should makes business function better.