The principle of Concentrations of Flow appears in many aspects of drainage. Understanding that it is critical to proper drainage design. It simply states that as water moves from larger areas through smaller areas, flow rates increase.
We see this every day on our golf courses when water runs off of hillsides. Not only is the bottom of the slope the wettest, but areas that run between mounds or valleys where the flow travels will be the wettest. These areas have to handle not only the water that is falling on the flow area, but the water that has fallen on the watershed above it. If we don’t collect this water before it concentrates in these areas, the heavy Concentrations …