A combination of the STORM runoff model and a two-dimensional dynamic lake type model successfully reproduced the fecal coliform levels of an urban beach on a lake in the Ottawa River. The elevated fecal coliform levels were associated with rainfall events and runoff from two large catchments upstream of the beach. Due to prevailing conditions in the lake the second largest summer storm did not produce elevated fecal coliform levels while the third and fourth largest storms did. The models predicted these events.The STORM model was calibrated on a subcatehment and supplied the runoff flow volumes and pollution levels to the dynamic lake model. The other input data for the lake model were supplied by field measurements.The models were used to assess the effectiveness of management options to improve the water quality on the beach. The most cost-effective option was identified by the model predictions. Key words: beach fecal coliform predictions, stormwater beach fecal coliforms, storm, runoff, modelling.