The primary objective of this study was to develop a real time automatic control model that could be used in connection with a combined sewer system to minimize overflows during storms. The model was applied to the North Shore Outfall Consolidation Project in San Francisco. This project consists of a large transport storage facility that intercepts existing outfalls and allows flows to be pumped to a primary or a secondary treatment plant depending on operational strategy. Four reactive control strategies and one reactive-predictive strategy were formulated and evaluated for pollutant removal performance. The cost effectiveness of each was then determined.