Detailed Representation of a Large Pumping Station using EXTRAN

摘要

Rigorous representation of "real world" structures and systems in hydraulic and hydrologic models is a nontrivial task. Since the 1960s and 1970s when SWMM and other EPA models were developed, representation of the physical characteristics of systems has often been unduly simplified due to the lack of features in the model necessary to simulate the real physical system, simulation duration, or level of detail (Wisner et. al., 1984). Current increased computational capability provided by significant advances in computer technology coupled with the availability of tools that can be used to better measure, monitor and simulate real world structures provides a sound foundation for detailed representation of complex structures in hydraulic and hydrologic models. The addition of an array of structural and operational capabilities to SWMM such as the various pump types and settings has significantly improved its ability to rigorously represent and simulate real world structures. For a flooding study of the South End neighborhood in Boston, Massachusetts, it was desirable to rigorously represent a 500 cfs (14 m~3/s) pumping station which included a weir, three entry gates, screening channels, a large wet well, four pumps, pressure lines, and a tidally-influenced discharge chamber. A comprehensive flow-monitoring program was conducted to characterize inflow to the pumping station and field tests were conducted to develop head-capacity curves for pumps at the station. A SWMM model was developed and successfully used as a tool to evaluate facilities planning alternatives for the South End neighborhood served by the pumping station.