WRRCTR No.114 Digital Simulation and Evaluation of Storm Drainage Systems: St. Louis Heights Watershed Model

Abstract

The adequate design of a storm drainage system depends upon the proper estimation of various peak discharges (produced from a given storm) along the drainage network. The objective of this study is the development of a digital computer model utilizing available hydrologic data obtained during 1972 to 1975 to simulate runoff from given rainfall patterns in Hawaiian urban watersheds, and the development of procedures for channel flow routing through gutters and storm drains and runoff routing from pervious and impervious areas. The computer model is the result of using the kinematic wave equation, which is most suitable to steep topographic terrain such as that of the study area, to modify the overland, gutter, and sewer flow routing procedures of the well-known Illinois Urban-Drainage Area Simulator (ILLUDAS) model. Available infiltration data were used to modify the infiltration process. Examples of the system capacity design and evaluation, and computer programs for the application of this simulation model are presented for users' adaptation.