Open-Channel Capacity Determination Using Hydraulic Performance Graph

A method for determining the flow carrying capacity of a channel system, capable of accounting for the interacting backwater effect among channel reaches and incoming lateral flow, is presented here. The method makes use of hydraulic performance graphs-a new tool for dealing with open-channel-flow problems. The hydraulic performance graph summarizes all the backwater profile information for a channel reach. As an illustration, the method is applied to evaluate the channel capacities of a portion of Boneyard Creek in the city of Urbana, Ill. The example demonstrates that the channel flow capacity is a function of the exit water level, of which the maximum normal flow capacity and the absolute maximum carrying capacity are special cases.