What is the height requirement for a dike at the inlet of a sediment trap?

The height requirement for a dike at the inlet of a sediment trap is determined by ensuring that it is adequate to contain the flow and prevent sediment from bypassing the trap. By specifying that the dike's height should be equal to the pipe diameter plus 6 inches, the design ensures that there is sufficient elevation to account for potential variations in flow and sediment load. The additional height serves as a buffer to accommodate debris or other factors that might affect the water level, thereby enhancing the trap's effectiveness in capturing sediment before it can enter downstream areas.

This approach reflects an understanding of the hydrological and sedimentation processes at play, which is critical in managing stormwater runoff and minimizing erosion. It helps maintain the intended function of the sediment trap by ensuring that it can adequately capture and settle sediment while preventing overflow during high-flow events. The other options do not directly address this critical need for an appropriate dike height relative to flow dynamics and sediment capture within a sediment trap.