Cincinnati’s SWMM Model: A Journey Through Time

Abstract

The Metropolitan Sewer District of Greater Cincinnati's (MSD) SWMM model is one of the largest SWMM models in the world. In developing this model, MSD advanced the state-of-the-art in collection system modeling in a number of areas including the size and scope of the model, the application of radar rainfall data, the use of water consumption data to estimate dry weather flows, and the use of GIS for model development. It provided MSD with an extraordinary tool to evaluate existing and projected conditions and to use a modeled problem with a modeled solution approach for consent decree compliance. This paper provides the history, features and applications of the MSD SWMM model. Modeling challenges and lessons learned are also discussed.