ABSTRACT
A storm sewer system consists of a series of inlets, manholes, and pipes that collect and convey storm runoff from streets to the downstream collector. The importance of a storm drainage plan is to incorporate the existing natural waterways and man-made drainage facilities into the drainage system. The layout of a storm sewer system is governed by many factors, such as, existing utility locations, street alignment, inlet placement, outfall location, and surface topography. Manholes and junctions provide efficient transitions in the storm sewer system and also serve as the access passages to storm sewer lines for maintenance and cleaning. The sewer sizing process shall start from the most upstream manhole in the trunk line and then the march downstream as the flow rate and the time of concentration are accumulated downstream. The water surface profile represents the hydraulic gradient line (HGL) in a sewer line.
