Answer Happy

Example2: Open Channel Given: You are designing a storm sewer to carry a peak storm flow of 1500 gpm in pipe with a Manning's coefficient of n= 0.13.within the bottom 25% of the pipe's depth. Find: a) What size (diameter in inches) should you specify (remember to round up to the closest inch) if the slope is to be 1% and the flow is to be in the bottom 25% of the pipe's depth? b) If you selected a 16 inch pipe and allow it to flow 30% full, what slope will you need to install the pipe at? c) What do you predict the actual velocity of water to be if you selected a 16" pipe and allowed it to flow 40% full? d) If the actual velocity in the storm drain must be less than 5 ft/sec and the storm drain must flow at a depth less than 80% of its diameter, what is the smallest diameter and slope you would recommend? Solution: