A trapezoidal channel is to be designed to carry a maximum discharge of 800 cfs. The channel is to be grass lined and will run on a slope of 0.0035 ft/ft through material with an angle of repose  of...

A trapezoidal channel is to be designed to carry a maximum discharge of 800 cfs. The channel is to be grass lined and will run on a slope of 0.0035 ft/ft through material with an angle of repose
 of 35°

Conditions dictate that Lespedeza grass (50 cm height) will be the optimum lining. Determine the channel dimensions for this case.