Weather related episodic events are typically unpredictable and the episodic inputs of dissolved and particulate material during storm events can have important effects on lake and reservoir ecosystem function and also impact reservoir drinking water quality. We evaluate the impacts of storm events using vertical profiles of temperature, dissolved oxygen, turbidity and chlorophyll automatically collected at 6 hour intervals in West basin of Ashokan Reservoir, which is a part of the New York City drinking water supply. Using data from before, during and after storm events, we examine how the balance between GPP and R is influenced by storm related increases in turbidity and dissolved organic matter, which would in turn influence light attenuation and bacterial production. Storm driven inputs to the reservoir periodically resulted in large input of suspended sediments raising water turbidity beyond 25 NTU. This reduced the euphotic depth several meters? Reducing light availability and thus GPP. Storm inputs stimulated R through elevated external inputs of organic matter as well as internal inputs from upwelling.