Determine the upstream depth of flow in a subcritical transition from an upstream rectangular flume that is 49ft wide to a downstream trapezoidal channel with a width of 75ft and side slopes of 2:1. The transition bottom drops 1 ft from the upstream flume to the downstream trapezoidal channel. The flow rate is 12,600 cfs, and the depth in the downstream trapezoidal channel is 22ft. Use a head loss coefficient of 0.5.