CIV E 444 - APPLIED HYDRAULICS SPRING 2016 HOMEWORK No. 13 A watershed in coastal Southern California has a drainage area = 6.8 mi2, 24-hr rainfall = 4.5 in, and time of concentration = 1 hr. The current estimated curve number CN = 80. What reduction in CN would be necessary through watershed improvements in order to reduce the peak discharge to less than 80% of the current value? Use ONLINE TR55. What is the Darcy-Weisbach friction factor in a channel with Q = 7.2 m3/s, b = 1.2 m, z = 1, So = 0.0006, and n = 0.013? [Hint: Find critical slope using ONLINE CHANNEL 04].