A 36-in diameter water supply line was installed 20 years ago on a slope of 0.1% and designed to flow nearly full (D/d = 0.95). If the Manning coefficient at

time of installation was 0.015 and current pipe capacity is 15 cfs, answer the following: a) Calculate flow velocity immediately after installation b) Calculate current flow velocity and current value of Manning coefficient c) Briefly explain why a water supply line can be designed to flow safely whennearly full but a sewer or storm drain cannot