Street storm water conveyance capacity

The street hydraulic capacity to convey storm water is dictated by the street gutter geometry and hydraulic characteristics. With the consideration of traffic safety, the street hydraulic conveyance capacity (SHCC) is also subject to a reduction defined by the water velocity and flow depth in the street gutter. In this study, the street hydraulic equation is rearranged to demonstrate that the water velocity and depth product in a gutter flow can serve as a safety criterion for determining the allowable SHCC. The velocity and water depth product and discharge reduction methods were examined and revised to establish the consistency in predictions. The revised design procedures developed in this study replace the current iterative process with a direct estimation of the allowable SHCC when a safety criterion is specified.