A smooth concrete (n = 0.015) trapezoidal channel has longitudinal slope of 0.01, side slopes of 3/1 (H/V) and a bottom width of 10 feet. Discharge is estimated in the channel at 705 (cfs) cubic feet per second. The depth of flow at a gaging station is observed to be 3.25 feet.
(a) What is normal depth of flow in the channel?
(b) What is the critical depth of flow in the channel?
(c) Classify the slope of the channel and the water surface profile at the gaging station (e.g. mild, steep, etc.).
(d) If the bottom of the channel just downstream of the gaging station is raised by 0.65 feet, find the resulting depth of flow at the downstream section.