When constructing a pipe outlet sediment trap, how far below the top of the embankment must the top of the riser pipe be?

The requirement for the top of the riser pipe to be set 1.5 feet below the top of the embankment when constructing a pipe outlet sediment trap is established to ensure effective sediment control while maintaining the functionality of the trap. This specific height helps to prevent the overflow of sediment-laden water while still allowing for adequate water storage capacity in the sediment trap.

By setting the riser pipe at this height, the design ensures that sediment can settle out effectively in the trap's basin before water is permitted to exit the system. If the riser were too high, sediment would escape with the water flow, undermining the purpose of the sediment trap. Additionally, this height allows for fluctuations in water level and sediment accumulation without compromising the trap’s efficiency. Proper placement of the riser is crucial in managing stormwater runoff and minimizing erosion, thereby preserving the integrity of surrounding landscapes.