1) The critical depth for the given triangular channel with a 1:1.5 side slope and flowrate of 0.68 ft3/s is 0.53 ft. 2) The minimum specific energy is 0.66275 ft at the critical depth. 3) The specific energy curve plots energy (y-axis) versus depth (x-axis). At a depth of 0.45 ft, the energy is 0.705438 ft and there is an alternate depth of 0.645 ft with the same specific energy.